Tootfinder

A porous medium equation with spatially inhomogeneous absorption. Part II: Large time behavior
Razvan Gabriel Iagar, Diana-Rodica Munteanu
https://arxiv.org/abs/2508.11046 https…

A porous medium equation with spatially inhomogeneous absorption. Part II: Large time behavior
We study the large time behavior of solutions to the Cauchy problem for the quasilinear absorption-diffusion equation $$ \partial_tu=Δu^m-|x|^σu^p, \quad (x,t)\in\real^N\times(0,\infty), $$ with exponents $p>m>1$ and $σ>0$ and with initial conditions either satisfying $$ u_0\in L^{\infty}(\real^N)\cap C(\real^N), \quad \lim\limits_{|x|\to\infty}|x|^θu_0(x)=A\in(0,\infty) $$ for some $θ\geq0$. A number of different asymptotic profiles are identified, and unifor…

A Tale of Two Sightlines: Comparison of Hydrocarbon Dust Absorption Bands toward Cygnus OB2-12 and the Galactic Center
Yvonne J. Pendleton, T. R. Geballe, Laurie E. U. Chu, Marjorie Decleir, Karl D. Gordon, A. G. G. M. Tielens, Louis J. Allamandola, Jeroen Bouwman, J. E. Chiar, Curtis Dewitt, Burcu Gunay, Thomas Henning, Vito Mennella, M. E. Palumbo, Alexey Potapov, Maisie Rashman, Sasha Zeegers

A Tale of Two Sightlines: Comparison of Hydrocarbon Dust Absorption Bands toward Cygnus OB2-12 and the Galactic Center
Infrared spectra of hydrocarbon dust absorption bands toward the bright hypergiant Cygnus OB2-12 are compared to published spectra of the Quintuplet Cluster, a sightline to the Galactic center. The Cyg OB2-12 data include a new ground-based 2.86-3.70 microns spectrum and a previously published, but here further analyzed, spectrum of the 5.50-7.34 microns region. Higher spectral resolution data for the Cyg OB2-12 sightline in the 3 micron region allows a detailed comparison of the 3.4 micron ali…

Dual-species atomic absorption image reconstruction using deep neural networks
Kyuhwan Lee, Yong-il Shin
https://arxiv.org/abs/2508.12120 https://arxiv.org…

Dual-species atomic absorption image reconstruction using deep neural networks
Optical imaging plays an instrumental role in understanding the behavior of trapped neutral atoms. In this work, we describe a deep learning-based online image completion protocol that reduces interference fringes in optical absorption signals for a dual-species atomic system. Regardless of the distinct nature of the task for two different atomic species, 6Li and 23Na, the method displays a robust solution for suppressing fringes. To incorporate this into daily operations, a transfer learning s…

Antiferromagnetic resonance and two-magnon absorption in an XXZ-chain antiferromagnet Cs2CoCl4
T. A. Soldatov, A. I. Smirnov
https://arxiv.org/abs/2509.13953 https://

Antiferromagnetic resonance and two-magnon absorption in an XXZ-chain antiferromagnet Cs2CoCl4
Magnetic excitations of the exchange-dipole quasi 1D XXZ antiferromagnet are studied in the ordered phase. We observe a transformation of the electron spin resonance (ESR) spectrum when crossing the Néel temperature near 0.2 K. The single-mode ESR of a correlated XXZ chain transforms in the multi-mode spectrum in the ordered phase. The multi-mode spectrum consists mainly of the intensive mode of a single correlated chain, which is surrounded and/or indented by numerous weak satellites. The num…

Gravitational perturbations of Dymnikova black holes: grey-body factors and absorption cross-sections
Alexey Dubinsky
https://arxiv.org/abs/2509.11017 https://

Gravitational perturbations of Dymnikova black holes: grey-body factors and absorption cross-sections
We study axial gravitational perturbations of the Dymnikova regular black hole, an asymptotically flat spacetime in which the Schwarzschild singularity is replaced by a de Sitter core. Using the WKB method with Padé approximants, we compute grey-body factors, and absorption cross-sections, and test the recently proposed correspondence between quasinormal frequencies and transmission coefficients. We find that variations of the quantum parameter \(l_{\rm cr}\) affect the effective potential onl…

Quantum Control of Thermal Emission from Photonic Crystals with Two-Level Atoms
Chih-Wei Wang, Jhih-Sheng Wu
https://arxiv.org/abs/2508.11191 https://arxiv…

Quantum Control of Thermal Emission from Photonic Crystals with Two-Level Atoms
Thermal light engineering is a field of considerable interest and potential. We study quantum light-matter interactions in a one-dimensional photonic crystal with two-level atoms as the active medium, replacing classical oscillators in traditional blackbody models. In a thermal bath with pumping, these atoms modulate thermal emission via interactions with photonic modes. The model with quantum two-level systems enables the processes of spontaneous emission, stimulated absorption, and stimulated…

XASDB -- Design and Implementation of an Open-Access Spectral Database
Denis Spasyuk
https://arxiv.org/abs/2509.13566 https://arxiv.org/pdf/2509.13566

XASDB - Design and Implementation of an Open-Access Spectral Database
The increasing volume and complexity of X-ray absorption spectroscopy (XAS) data generated at synchrotron facilities worldwide require robust infrastructure for data management, sharing, and analysis. This paper introduces the XAS Database (XASDB), a comprehensive web-based platform developed and hosted by the Canadian Light Source (CLS). The database houses more than 1000 reference spectra spanning 40 elements and 324 chemical compounds. The platform employs a Node.js/MongoDB architecture desi…

The Type II SN 2025pht in NGC 1637: A Red Supergiant with Carbon-rich Circumstellar Dust as the First JWST Detection of a Supernova Progenitor Star
Charles D. Kilpatrick, Aswin Suresh, Kyle W. Davis, Maria R. Drout, Ryan J. Foley, Alexander Gagliano, Wynn V. Jacobson-Galan, Ravjit Kaur, Kirsty Taggart, Jason Vazquez
https://arxiv.org/abs/2…

The Type II SN 2025pht in NGC 1637: A Red Supergiant with Carbon-rich Circumstellar Dust as the First JWST Detection of a Supernova Progenitor Star
We present follow-up imaging and spectroscopy and pre-explosion imaging of supernova (SN) 2025pht located in NGC 1637 at 12 Mpc. Our spectroscopy shows that SN 2025pht is a Type II SN with broad lines of hydrogen and with minimal line-of-sight extinction inferred from Na I D absorption. NGC 1637 was the target of several epochs of Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) imaging covering the site of SN 2025pht from 31 to 0.7 yr prior to discovery. Using a follow-up HST…

Efficient neutral-IGM inference from noisy 21-cm forest spectra with latent-space U-Net encoding and XGBoost
Sameer K. Patil, Tom\'a\v{s} \v{S}oltinsk\'y, Soumak Maitra, Girish Kulkarni
https://arxiv.org/abs/2507.11611

Efficient neutral-IGM inference from noisy 21-cm forest spectra with latent-space U-Net encoding and XGBoost
The 21-cm forest, comprising narrow absorption features imprinted on the radio spectra of high-redshift radio-loud quasars by intervening neutral hydrogen, offers a uniquely sensitive probe of the thermal state of the neutral intergalactic medium (IGM) during the epoch of reionization. Although over 30 such quasars are now known at $z > 5.5$, the signal remains elusive in practice, owing to instrumental noise, the intrinsic weakness of the absorption features, and the limited brightness of avai…

Replaced article(s) found for astro-ph.EP. https://arxiv.org/list/astro-ph.EP/new
[1/1]:
- Strong NUV Refractory Absorption and Dissociated Water in the Hubble Transmission Spectrum of the...
Chachan, Lothringer, Inglis, Beltz, Knutson, Spake, Benneke, Wong, Rustamkulov, Sing, Bennett…

Tuning and Suppression of YIG Magnetisation Dynamics via Antiferromagnetic Interface Coupling
Oscar Cespedes, Hari B. Vasili, Matthew Rogers, Paul S. Keatley, Manan Ali, Bryan Hickey, Robert J. Hicken
https://arxiv.org/abs/2509.13870

Tuning and Suppression of YIG Magnetisation Dynamics via Antiferromagnetic Interface Coupling
The magnetisation dynamics of yttrium iron garnet (Y3Fe5O12, YIG) are key to the operation of spintronic and microwave devices. Here, we report a pathway to manipulate the frequency, damping and absorption of YIG thin films via interface coupling. The growth on YIG of PtMn, a metallic antiferromagnet, leads to a power dependence of the oscillation frequency and an increased linewidth at low fields. In gadolinium iron garnet/YIG film bilayers, the two films couple antiferromagnetically at low te…

Shock absorption by multilayer carbon nanotube packings
Alexander V. Savin
https://arxiv.org/abs/2507.12034 https://arxiv.org/pdf/250…

Shock absorption by multilayer carbon nanotube packings
The propagation of transverse impact energy in a multilayer packing (in an array) of parallel single-walled carbon nanotubes has been simulated. It has been shown that such nanotube arrays are effective shock absorbers. The depreciation effect is most pronounced for packings of nanotubes with a diameter of 2.7-3.9 nm. Here, part of the impact energy is absorbed due to the transfer of the packing to a higher energy stationary state, in which part of the nanotubes is in a collapsed state. The imp…

Automatic computation of the glycemic index: data driven analysis of the glucose standard
Fabio Credali, Maria Teresa Venuti, Daniele Boffi, Paola Rossi
https://arxiv.org/abs/2506.15471

Automatic computation of the glycemic index: data driven analysis of the glucose standard
The Glycemic Index (GI) is a tool for classifying carbohydrates based on their impact on postprandial glycemia, useful for diabetes prevention and management. This study applies a mathematical model for a data driven simulation of the glycemic response following glucose ingestion. The analysis reveals a direct correlation between glucose response profiles and parameters describing glucose absorption, enabling the classification of subjects into three groups based on the timing of their glycemic…

Imaginary part of the conductivity using Kramers-Kronig relations
Jean-Christophe Pain, Mikael Tacu
https://arxiv.org/abs/2506.14941 https://

Imaginary part of the conductivity using Kramers-Kronig relations
In order to obtain the frequency-dependent photo-absorption in a plasma, both the real and imaginary parts of the AC conductivity are required. The real part can be deduced from the knowledge of the static conductivity (given by the Ziman-Evans formula for instance) and the Drude model. The imaginary part, required for the refraction index, can be obtained using the Kramers-Kronig relations. Usually, it is obtained by complex integration in the complex plane of the usual Kramers-Kronig relation…

Apparent Resonance Splitting in Self-Coupled Excitonic Systems
Avishek Sarbajna, Qitong Li, Dorte Rub{\ae}k Danielsen, Skyler Peitso Selvin, Duc Hieu Nguyen, Manh-Ha Doan, Peter B{\o}ggild, Mark L. Brongersma, S{\o}ren Raza
https://arxiv.org/abs/2508.11370

Apparent Resonance Splitting in Self-Coupled Excitonic Systems
Thin films of high-refractive-index excitonic materials enable self-coupling by simultaneously supporting intrinsic excitonic transitions and optical resonances. These optical resonances take the form of Fabry-Perot resonances in thick films and absorption resonances in ultrathin films placed on metallic substrates. Here, we investigate whether these optical resonances lead to true exciton-photon hybridization. Using far-field reflectance and spectrally resolved photocurrent measurements, we st…

Determination of absorption by Q-method for JHK photometry in embedded clusters
T. A. Permyakova (Kourovka Astronomical Observatory, Ural Federal University, Ekaterinburg, Russia)
https://arxiv.org/abs/2507.11065

Determination of absorption by Q-method for JHK photometry in embedded clusters
In this paper we describe the absorption determination by the Q-method for 2MASS photometry ($J$, $H$ and $K_S$ bands). Using the Pleiades and Praesepe stars, we determine the zero-reddening sequence for different values of the color excess ratios $E(J-H)/E(H-K_S)$. In this paper we consider a sequence consisting of two segments, that leads to an uncertainty in the determining of absorption - one value of the Q parameter corresponds to two values of the non-reddened color index. We propose a me…

Foreground and internal free-free absorption in particle-accelerating colliding-wind binaries : Insights from the radio emission of WR 147
M. Tasseroul, M. De Becker, A. B Blanco, P. Benaglia, S. del Palacio
https://arxiv.org/abs/2508.10506

Foreground and internal free-free absorption in particle-accelerating colliding-wind binaries : Insights from the radio emission of WR 147
Radio emission from massive binary systems is generally of composite nature, showing both a thermal emission component from the winds and a non-thermal component from relativistic electrons accelerated in the colliding-wind region. Understanding the processes ruling their radio spectrum is essential to investigate the role of these objects in the production of non-thermal particle populations in our galaxy. Our objective is to explore how the processes at work in particle-accelerating colliding…

Replaced article(s) found for hep-ph. https://arxiv.org/list/hep-ph/new
[2/2]:
- Determination of the $\phi$-meson production process and its absorption cross section via directe...
Jan Steinheimer, Tom Reichert, Marcus Bleicher

Replaced article(s) found for gr-qc. https://arxiv.org/list/gr-qc/new
[2/2]:
- Photon Absorption in a Doubly Special Relativity Model with Undeformed Free Propagation and Total...
J. M. Carmona, J. L. Cort\'es, F. Rescic, M. A. Reyes, T. Terzi\'c

Ionization and temperature measurements in warm dense copper using x-ray absorption spectroscopy
T. Cordova, E. V. Marley, D. A. Chin, R. A. London, H. A. Scott, T. D\"oppner, F. N. Beg, F. Coppari, M. Millot, J. Emig, S. B. Hansen, P. M. Nilson, P. Sterne, M. J. MacDonald
https://arxiv.org/abs/2509.13272

💔 Climate-protecting carbon sinks of EU forests are declining
#forests

Climate-protecting carbon sinks of EU forests are declining
Forests cover about 40% of the EU's land area. Between 1990 and 2022, they absorbed around 10% of the continent's man-made carbon emissions. However, the carbon dioxide absorption capacity of forests, also known as carbon sinks, is becoming increasingly weaker.

The Broadband View of the Bare Seyfert PG 1426 015: Relativistic Reflection, the Soft Excess and the Importance of Oxygen
D. J. Walton, A. Madathil-Pottayil, P. Kosec, J. Jiang, J. Garcia, A. C. Fabian, C. Pinto, D. J. K. Buisson, M. L. Parker, W. N. Alston, C. S. Reynolds
https://arxiv.org/abs/2509.13411

The Broadband View of the Bare Seyfert PG 1426+015: Relativistic Reflection, the Soft Excess and the Importance of Oxygen
We present results from a deep, coordinated $XMM$-$Newton$ + $NuSTAR$ observation of the type 1 Seyfert PG 1426+015, a source of particular interest as the most massive reverberation-mapped black hole to date ($\log [M_{\rm{BH}}/M_{\odot}]$ = $9.01^{+0.11}_{-0.16}$). The high-resolution RGS data confirm the 'bare' nature of the source, showing no evidence for absorption beyond the Galactic column, while the broadband spectrum unambiguously reveals the presence of relativistic reflection from th…

A remarkable ruby - absorption in dense gas, rather than evolved stars, drives the extreme Balmer break of a #LittleRedDot at z = 3.5: https://www.aanda.org/articles/aa/full_html/2025/09/aa54681-25/aa54681-25.html -> “Black Hole Stars” could solve JWST riddle of overly massive early galaxies: https://www.mpia.de/news/science/2025-06-black-hole-stars

Quantifying CO2 Distribution at the Air-Water Interface - Spatiotemporally Resolved Measurements Using Tunable Diode Laser Spectroscopy
Dongfang Zhao, Yumin Shi, Shengkai Wang
https://arxiv.org/abs/2509.13113

Quantifying CO2 Distribution at the Air-Water Interface - Spatiotemporally Resolved Measurements Using Tunable Diode Laser Spectroscopy
The transport of CO2 across the air-water interface plays a critical role in physical oceanography and carbon sequestration. One of the key challenges in understanding such transport processes is their multiscale nature - the spatial and temporal scales of gas- and liquid-phase diffusion, absorption and reaction span over several orders of magnitude, which requires high-resolution diagnostic methods to unravel their detailed dynamics. The current study presents a novel diagnostic method to quan…

Sensitivity of x-ray absorption at $5d$ edges of high-valent light actinides to crystal-field strength and covalency effects
Johan Vegelius, David K. Shuh, Sergei M. Butorin
https://arxiv.org/abs/2507.10723

Sensitivity of x-ray absorption at $5d$ edges of high-valent light actinides to crystal-field strength and covalency effects
The $5f$ states were probed in ThO$_2$ and U(VI) and U(V) oxides using x-ray absorption spectroscopy at the actinide $O_{4,5}$ edges. Measured data were analyzed by several approaches including atomic, crystal-field theory and the Anderson impurity model to take into account the hybridization of actinide valence states with oxygen $2p$ states. For Th(IV), the $5f$ states are mainly affected by the crystal-field interaction with the closest neighbors as can be seen from the corresponding spectru…

Probing Stellar Kinematics with the Time-Asymmetric Hanbury Brown and Twiss Effect
Lucijana Stanic, Ivan Cardea, Edoardo Charbon, Domenico Della Volpe, Daniel Florin, Andrea Guerrieri, Gilles Koziol, Etienne Lyard, Nicolas Produit, Aramis Raiola, Prasenjit Saha, Vitalii Sliusar, Achim Vollhardt, Roland Walter
https://arxiv.org/abs/2509.131…

Probing Stellar Kinematics with the Time-Asymmetric Hanbury Brown and Twiss Effect
Intensity interferometry (II) offers a powerful means to observe stellar objects with a high resolution. In this work, we demonstrate that II can also probe internal stellar kinematics by revealing a time-asymmetric Hanbury Brown and Twiss (HBT) effect, causing a measurable shift in the temporal correlation peak away from zero delay. We develop numerical models to simulate this effect for two distinct astrophysical scenarios: an emission-line circumstellar disk and an absorption-line binary sys…

Quantum Effects for Black Holes with On-Shell Amplitudes
Katsuki Aoki, Andrea Cristofoli, Hyun Jeong, Matteo Sergola, Kaho Yoshimura
https://arxiv.org/abs/2509.12111 https://

Quantum Effects for Black Holes with On-Shell Amplitudes
We develop a framework based on modern amplitude techniques to analyze emission and absorption effects in black hole physics, including Hawking radiation. We first discuss quantum field theory on a Schwarzschild background in the Boulware and Unruh vacua, and introduce the corresponding $S$-matrices. We use this information to determine on-shell absorptive amplitudes describing processes where a black hole transitions to a different mass state by absorbing or emitting quanta, to all orders in g…

Citation Issues in Wave Mechanics Theory of Microwave Absorption
Yue Liu, Ying Liu, Michael G. B. Drew
https://arxiv.org/abs/2508.06522 https://arxiv.org/p…

Citation Issues in Wave Mechanics Theory of Microwave Absorption
The wave mechanics theory of microwave absorption challenges the long-standing impedance-matching and quarter-wavelength paradigms by demonstrating that conventional models mistakenly conflate bulk material parameters with thin-film phenomena. Drawing on a corpus of 35 peer-reviewed papers and preprints, the study performs a citation-pattern analysis and a logical audit of established theory. Results reveal a striking asymmetry in scholarly engagement, only a handful of supportive or neutral ci…

Thermal Cesium Release in PMTs Revealed by Resonant Laser Spectroscopy and Its Correlation with Quantum Efficiency
Antonio De Benedittis, Pasquale Migliozzi, Carlos Maximiliano Mollo, Andreino Simonelli
https://arxiv.org/abs/2509.13168

Thermal Cesium Release in PMTs Revealed by Resonant Laser Spectroscopy and Its Correlation with Quantum Efficiency
We report optical evidence of cesium (Cs) evaporation from a bialkali (SbKCs) photo- cathode during controlled heating of a photomultiplier tube (PMT). A DFB laser scanned across the 852.113 nm Cs D2 line reveals absorption features only above 60 degrees Celsius, indicating thermal desorption. The absorption correlates with temperature and offers a non-invasive method to monitor photocathode degradation in sealed detectors.

Replaced article(s) found for physics.ao-ph. https://arxiv.org/list/physics.ao-ph/new
[1/1]:
- MARFA: an Effective Line-by-line Tool For Calculating Molecular Absorption in Planetary Atmospheres
Mikhail Razumovskiy, Boris Fomin, Denis Astanin

Experimental study of the acoustic frequency-up conversion effect by nonlinear thin plates
Alexis Mousseau, Soizic Terrien, Vincent Tournat
https://arxiv.org/abs/2509.12785 http…

Experimental study of the acoustic frequency-up conversion effect by nonlinear thin plates
Classical methods of sound absorption present fundamental limits that can be overcome by using nonlinear effects. Thin clamped plates have been identified as strongly nonlinear elements, capable of transferring the acoustic power of an incident air-borne wave towards higher frequencies. Here, we experimentally show that these plates exhibit different vibrational nonlinear behaviors depending on the amplitude and frequency of the excitation signal. The lowest excitation levels achieved lead to h…

Probing ultrafast heating and ionization dynamics in solid density plasmas with time-resolved resonant X-ray absorption and emission
Lingen Huang, Mikhail Mishchenko, Michal \v{S}m\'id, Oliver Humphries, Thomas R. Preston, Xiayun Pan, Long Yang, Johannes Hagemann, Thea Engler, Yangzhe Cui, Thomas Kluge, Carsten Baehtz, Erik Brambrink, Alejandro Laso Garcia, Sebastian G\"ode, Christian Gutt, Mohamed Hassan, Hauke H\"oppner, Michaela Kozlova, Josefine Metzkes-Ng, Masruri Ma…

Probing ultrafast heating and ionization dynamics in solid density plasmas with time-resolved resonant X-ray absorption and emission
Heating and ionization are among the most fundamental processes in ultra-short, relativistic laser-solid interactions. However, capturing their spatiotemporal evolution experimentally is challenging due to the inherently transient and non-local thermodynamic equilibrium (NLTE) nature. Here, time-resolved resonant X-ray emission spectroscopy, in conjunction with simultaneous X-ray absorption imaging, is employed to investigate such complex dynamics in a thin copper wire driven by an optical high…

An Ultraviolet Study of CO Chemistry in the Magellanic Clouds
Kirill Tchernyshyov, Jessica K. Werk, Julia Roman-Duval
https://arxiv.org/abs/2508.10996 https://

An Ultraviolet Study of CO Chemistry in the Magellanic Clouds
How does molecular cloud chemistry change with metallicity? In this work, we study the relation between molecular hydrogen ($H_2$) and carbon monoxide (CO) at $1/2$ and $1/5$ solar metallicity using ultraviolet absorption spectroscopy obtained as part of the UV Legacy Library of Young Stars as Essential Standards (ULLYSES) Hubble Space Telescope (HST) program. We determine CO column densities or upper limits for a sample of 50 lines of sight through the Large and Small Magellanic Clouds (LMC an…

Animals boost tropical forests' carbon absorption by aiding seed dispersal #environment

Animals boost tropical forests' carbon absorption by aiding seed dispersal
A lot of attention has been paid to how climate change can drive biodiversity loss. Now, MIT researchers have shown that the reverse is also true: Reductions in biodiversity can jeopardize one of Earth's most powerful levers for mitigating climate change.

"Animals boost tropical forests' carbon absorption by aiding seed dispersal"
#Animals #Trees #Forests

Animals boost tropical forests' carbon absorption by aiding seed dispersal
A lot of attention has been paid to how climate change can drive biodiversity loss. Now, MIT researchers have shown that the reverse is also true: Reductions in biodiversity can jeopardize one of Earth's most powerful levers for mitigating climate change.

Hydrogen absorption in intermetallic compounds from first principles
Olivier Nadeau, Romuald B\'ejaud, Lucas Baguet, Gr\'egory Geneste, Fran\c{c}ois Bottin, Gabriel Antonius
https://arxiv.org/abs/2509.05136

Hydrogen absorption in intermetallic compounds from first principles
Intermetallic compounds such as {A$_{2}$B$_{7}$} alloys are promising candidates for mobile hydrogen storage applications due to their high and reversible hydrogen absorption capacity. We compute the absorption isotherm of {Nd$_{3}$MgNi$_{14}$} from first-principles using a multiscale modeling approach. Absorption sites are identified through a systematic geometrical analysis, and are characterized with Density Functional Theory (DFT) calculations. The absorption site properties are used in roo…

Double White Dwarf Binaries in SDSS-V DR19 : The discovery of a rare DA DQ white dwarf binary with 31 hour orbital period
Gautham Adamane Pallathadka, Vedant Chandra, Boris T. Gansicke, Nadia L. Zakamska, Detlev Koester, Yossef Zenati, Nicole R. Crumpler, Stefan M. Arseneau, J. J. Hermes, Matthias R. Schreiber, Keivan G. Stassun, Axel Schwope, Kareem El-Badry, Gagik Tovmassian, Tim Cunningham, Sean Morrison

Double White Dwarf Binaries in SDSS-V DR19 : The discovery of a rare DA+DQ white dwarf binary with 31 hour orbital period
Binaries of two white dwarfs (WDs) are an important class of astrophysical objects that are theorized to lead to Type Ia supernovae and are also used to gain insight into complex processes involved in stellar binary evolution. We report the discovery of SDSS~J090618.44+022311.6, a rare post-common envelope binary of a hydrogen atmospheric DA WD and a DQ WD which shows carbon absorption features, and is only the fourth such binary known. We combine the available spectroscopic, photometric, and r…

New dataset offers unprecedented detail on ocean carbon absorption, revealing short-term fluctuations and insights into climate impacts. #climatechange #climatesolutions #climate

Satellites reveal how oceans absorb carbon in unprecedented detail
New satellite maps reveal how oceans absorb carbon, offering real-time insight into climate shifts and ocean acidification.

Replaced article(s) found for astro-ph.EP. https://arxiv.org/list/astro-ph.EP/new
[1/1]:
- MARFA: an Effective Line-by-line Tool For Calculating Molecular Absorption in Planetary Atmospheres
Mikhail Razumovskiy, Boris Fomin, Denis Astanin

Specific Absorption Rate-Aware Multiuser MIMO Assisted by Fluid Antenna System
Yuqi Ye, Li You, Hao Xu, Ahmed Elzanaty, Kai-Kit Wong, Xiqi Gao
https://arxiv.org/abs/2507.03351

Specific Absorption Rate-Aware Multiuser MIMO Assisted by Fluid Antenna System
With the development of the upcoming sixth-generation (6G) wireless networks, there is a pressing need for innovative technologies capable of satisfying heightened performance indicators. Fluid antenna system (FAS) is proposed recently as a promising technique to achieve higher data rates and more diversity gains by dynamically changing the positions of the antennas to form a more desirable channel. However, worries regarding the possibly harmful effects of electromagnetic (EM) radiation emitte…

Additive properties and absorption laws for generalized inverses
Yukun Zhou, Jianlong Chen, Nestor Thome
https://arxiv.org/abs/2508.04363 https://arxiv.org…

Additive properties and absorption laws for generalized inverses
Let $a,~f$ be elements in a ring with pseudo core inverses $a^{\scriptsize\textcircled{\tiny D}}$, $f^{\scriptsize\textcircled{\tiny D}}$, and let $b=f-a$. We prove that the absorption law $a^{\scriptsize\textcircled{\tiny D}}(a+f)f^{\scriptsize\textcircled{\tiny D}}=a^{\scriptsize\textcircled{\tiny D}}+f^{\scriptsize\textcircled{\tiny D}}$ holds if and only if $1+a^{\scriptsize\textcircled{\tiny D}}b$ is invertible and the additive property $f^{\scriptsize\textcircled{\tiny D}}=(1+a^{\scriptsi…

Balmer Absorption in Iron Low-Ionization Broad Absorption Line Quasars
Karen M. Leighly, Sarah C. Gallagher, Hyunseop Choi, Donald M. Terndrup, Julianna R. Voelker, Gordon T. Richards, Leah K. Morabito
https://arxiv.org/abs/2509.07611

Balmer Absorption in Iron Low-Ionization Broad Absorption Line Quasars
While C IV is the most common absorption line in Broad Absorption Line Quasar spectra, Balmer absorption lines are among the rarest. We present analysis of Balmer absorption in a sample of fourteen iron low-ionization BAL quasars (FeLoBALQs); eight are new identifications. We measured velocity offset, width, and apparent optical depth. The partial covering ubiquitous in BAL quasar spectra alters the measured Balmer optical depth ratios; taking that into account, we estimated the true H(n= 2) co…

Attosecond Transient Absorption Study of Coherent Hole Oscillation in Ar
Nisnat Chakraborty, Miguel Alarcon, Michael P. McDonnell, Karl Hauser, Islam Shalaby, Dipayan Biswas, James K. Wood, Nikolay V. Golubev, Arvinder Sandhu
https://arxiv.org/abs/2508.10261

Tunable Plasmonic Absorption in Metal-Dielectric Multilayers via FDTD Simulations and an Explainable Machine Learning Approach
Emmanuel A. Bamidele
https://arxiv.org/abs/2508.04014

Tunable Plasmonic Absorption in Metal-Dielectric Multilayers via FDTD Simulations and an Explainable Machine Learning Approach
Plasmonic devices, fundamental to modern nanophotonics, exploit resonant interactions between light and free electrons in metals to achieve enhanced light trapping and electromagnetic field confinement. However, modeling their complex, nonlinear optical responses remains computationally intensive. In this work, we combine finite-difference time-domain simulations with machine learning to simulate and predict absorbed power behavior in multilayer plasmonic stacks composed of SiO2, gold, silver, …

An improved model for the effect of correlated Si-III absorption on the one-dimensional Lyman-$\alpha$ forest power spectrum
Ke Ma, James S. Bolton, Vid Irsic, Prakash Gaikwad, Ewald Puchwein
https://arxiv.org/abs/2509.08613

An improved model for the effect of correlated Si-III absorption on the one-dimensional Lyman-$α$ forest power spectrum
We present an analysis of Si-III absorption and its effect on the 1D Ly$α$ forest power spectrum using the Sherwood-Relics hydrodynamical simulation suite. In addition to the well-understood oscillations arising from the Ly$α$--Si-III cross correlation, we find an enhancement in small-scale power that has been ignored in previous studies. We therefore develop a new analytical fitting function that captures two critical effects that have previously been neglected: distinct Ly$α$ and Si-III li…

Identification of Likely Methane Absorption Features in the Optical Spectra of Titan
Sirinrat Sithajan, Lalita Kaewbiang, Hugh R. A. Jones, Pakakaew Rittipruk, Sukanya Meethong
https://arxiv.org/abs/2509.06496

Identification of Likely Methane Absorption Features in the Optical Spectra of Titan
The optical spectra of Titan reveal a rich set of absorption features, most of which are likely associated with methane (CH$_4$). Methane is a key molecule in planetary and exoplanetary atmospheres, yet a comprehensive high-resolution linelist at optical wavelengths remains incomplete. This study identified and characterized potential CH$_4$ absorption features in high-resolution optical spectra of Titan, providing essential data for linelist development and improving CH$_4$ detection and chara…

WAFER: A new method to retrieve sun-induced fluorescence based on spectral wavelet decompositions
Veronika Oehl, Alexander Damm
https://arxiv.org/abs/2509.11829 https://

WAFER: A new method to retrieve sun-induced fluorescence based on spectral wavelet decompositions
Sun-induced fluorescence (SIF) as a close remote sensing based proxy for photosynthesis is accepted as a useful measure to remotely monitor vegetation health and gross primary productivity. In this work we present the new retrieval method WAFER (WAvelet decomposition FluorEscence Retrieval) based on wavelet decompositions of the measured spectra of reflected radiance as well as a reference radiance not containing fluorescence. By comparing absolute absorption line depths by means of the corresp…

Replaced article(s) found for cond-mat.mes-hall. https://arxiv.org/list/cond-mat.mes-hall/new
[2/2]:
- Observation of Perfect Absorption in Hyperfine Levels of Molecular Spins with Hermitian Subspaces
Bonizzoni, Lamberto, Napoli, Gunzler, Rieger, Santanni, Ghirri, Wernsd…

Intestinal villi and crypts density maximizing nutrient absorption
Martin Garic, Rohan Vernekar, D\'acil I. Y\'anez Mart\'in, St\'ephane Tanguy, Cl\'ement de Loubens, Claude Loverdo
https://arxiv.org/abs/2507.03472

Intestinal villi and crypts density maximizing nutrient absorption
The villi and crypts of the gastrointestinal tract increase the effective surface area of the intestinal mucosa, potentially enhancing nutrient absorption. It is commonly assumed that this is their primary function, and that a higher villi density necessarily leads to improved absorption. However, when villi are packed too closely together, diffusion can be hindered, potentially offsetting this benefit. In this work, we investigate the relationship between the density of these structures and th…

Tracking photophysical relaxation in spiropyran with simulated time-resolved X-ray absorption spectroscopy
Lina Frans\'en, Benjamin Roux, Sonia Coriani, Saikat Nandi, Morgane Vacher
https://arxiv.org/abs/2509.07002

Tracking photophysical relaxation in spiropyran with simulated time-resolved X-ray absorption spectroscopy
Spiropyran is a prototype photoswitch that undergoes photoinduced ring-opening via C-O bond fission. The quantum yield for this photochemical reaction is low, with photophysical relaxation being the dominant process. Previous theoretical studies have suggested that photophysical relaxation proceeds via cleavage and subsequent reformation of a C-N bond. However, experimental evidence for this mechanism is lacking; most time-resolved studies have probed in the ultraviolet-visible domain, where C-…

English translation of the paper "Electromagnetic field inside a plane-parallel layer in the resonant absorption regime" (1962) by A. P. Khapalyuk: Pioneering study on coherent perfect absorption
Denis V. Novitsky
https://arxiv.org/abs/2508.19687

English translation of the paper "Electromagnetic field inside a plane-parallel layer in the resonant absorption regime" (1962) by A. P. Khapalyuk: Pioneering study on coherent perfect absorption
In 1962, Belarusian physicist A. P. Khapalyuk has published the paper [Doklady Akademii nauk BSSR, volume 6, issue 5, pages 301-304] devoted to the effect of resonant absorption of light in a layer of matter. This work can be considered as a first study of the phenomenon known today as coherent perfect absorption (CPA). Unfortunately, the paper by A. P. Khapalyuk was published in a local journal in Russian and is almost unknown to the English-language scientific community. Here, we give the fir…

Comparing X-ray Emission Line Fluxes of NGC 5548 to NGC 1068
Divya Patel, Maryam Dehghanian, Gary Ferland
https://arxiv.org/abs/2508.13001 https://arxiv.or…

Comparing X-ray Emission Line Fluxes of NGC 5548 to NGC 1068
The Unification Model of AGN suggests that all AGN galaxies should exhibit similar line ratios in their spectra. NGC 5548, a Seyfert I, underwent obscuration -- similar to naturally obscured Seyfert II galaxies -- due to an outflowing accretion wind, resulting in absorption. As per the Model, a Seyfert I and a Seyfert II should show similar flux ratios during their respective obscuration states. In this note, we present a comparison of emission fluxes between NGC 5548 and NGC 1068, a Seyfert II…

Unveiling the Underwater World: CLIP Perception Model-Guided Underwater Image Enhancement
Jiangzhong Cao, Zekai Zeng, Xu Zhang, Huan Zhang, Chunling Fan, Gangyi Jiang, Weisi Lin
https://arxiv.org/abs/2507.06234

Unveiling the Underwater World: CLIP Perception Model-Guided Underwater Image Enhancement
High-quality underwater images are essential for both machine vision tasks and viewers with their aesthetic appeal.However, the quality of underwater images is severely affected by light absorption and scattering. Deep learning-based methods for Underwater Image Enhancement (UIE) have achieved good performance. However, these methods often overlook considering human perception and lack sufficient constraints within the solution space. Consequently, the enhanced images often suffer from diminish…

Hybrid integration of two-dimensional dichalcogenides for low power saturable absorption in photonic integrated circuits
Maria Carolina Volpato, Gustavo H. Magro, Antonio A. G. Von Zuben, Luis A. M. Barea, Pierre-Louis de Assis, Newton C. Frateschi
https://arxiv.org/abs/2509.09068

Hybrid integration of two-dimensional dichalcogenides for low power saturable absorption in photonic integrated circuits
Silicon photonics provides a versatile platform for large-scale integration of optical functions, but its weak intrinsic nonlinear response limits the realization of active, intensity-dependent functionalities. Hybrid integration of two-dimensional (2D) materials has emerged as a promising strategy to overcome these limitations by enabling strong light--matter interaction and broadband absorption. Here, we demonstrate saturable absorption in a Complementary Metal-Oxide-Semiconductor (CMOS)-comp…

Molecular Hydrogen in High-redshift Damped Lyman-{\alpha} Absorbers
Alon Gurman, Amiel Sternberg, Shmuel Bialy, Rachel K. Cochrane, Jonathan Stern
https://arxiv.org/abs/2508.13080

Molecular Hydrogen in High-redshift Damped Lyman-α Absorbers
Simulations predict that circumgalactic hydrogen gas surrounding massive ($M_{\rm{halo}}^{z=1}=10^{12}-10^{13}\ M_{\odot}$) galaxies at $z\sim4$ may be predominantly neutral, and could produce damped Ly$α$ absorbers (DLAs) along sight-lines to background quasars \citep{Stern2021}. A circumgalactic medium (CGM) origin for DLAs naturally explains high redshift HI absorption-selected galaxy detections at physical separations much greater than the likely extents of the galaxy disks \citep{Neeleman…

Ultrafast ps--TALIF and streak camera diagnostics of atomic hydrogen in a helium microplasma jet
Dimitrios Stefas (LSPM), Yanis Agha (LSPM), Laurent Invernizzi (LSPM), Jo\~ao Santos Sousa (LPGP), Swaminathan Prasanna (LSPM), Joachim Franzke (ISAS), Charalambos Anastassiou (UCY), Guillaume Lombardi (LSPM), Kristaq Gazeli (LSPM)
https://

Ultrafast ps--TALIF and streak camera diagnostics of atomic hydrogen in a helium microplasma jet
Picosecond two-photon absorption laser induced fluorescence (ps--TALIF) is combined with a streak camera ($\sim$1 ps highest temporal resolution) to probe the effective lifetime ($τ_{eff_{H(n=3)}}$) and absolute density ($N_H$) of atomic hydrogen in the effluent of a helium atmospheric-pressure microplasma jet ($μ$APPJ). This approach allows for improved temporal resolution compared to conventional nanosecond diagnostics, enabling measurements of $τ_{eff_{H(n=3)}}$ as small as 50 ps, the cor…

Distinguishing Majorana bound states from accidental zero-energy modes with a microwave cavity
Sarath Prem, Olesia Dmytruk, Mircea Trif
https://arxiv.org/abs/2509.13194 https://…

Distinguishing Majorana bound states from accidental zero-energy modes with a microwave cavity
Transport measurements of hybrid nanowires often rely on the observation of a zero-bias conductance peak as a hallmark of Majorana bound states (MBSs). However, such signatures can also be produced by trivial zero-energy Andreev bound states (ABSs) or by quasi-Majorana bound states (QMBSs), complicating their unambiguous identification. Here we propose microwave absorption visibility, extracted from parity-dependent cavity-nanowire susceptibility measurements, as a complementary probe of MBSs n…

Mean field control with absorption
Pierre Cardaliaguet, Joe Jackson, Panagiotis E. Souganidis
https://arxiv.org/abs/2509.07877 https://arxiv.org/pdf/2509.0…

Mean field control with absorption
In this paper we study a mean field control problem in which particles are absorbed when they reach the boundary of a smooth domain. The value of the N-particle problem is described by a hierarchy of Hamilton-Jacobi equations which are coupled through their boundary conditions. The value function of the limiting problem; meanwhile, solves a Hamilton-Jacobi equation set on the space of sub-probability measures on the smooth domain, i.e. the space of non-negative measures with total mass at most …

Suppressing secondary shock waves in jam-absorption driving via string-stable support vehicles
Atsushi Suzuki, Akihiro Tokumitsu, Ryosuke Nishi
https://arxiv.org/abs/2508.03604 …

Suppressing secondary shock waves in jam-absorption driving via string-stable support vehicles
As a freeway-driving strategy, jam-absorption driving (JAD) clears a shock wave (i.e., an upstream-moving congestion wave) by modulating the velocity of a single vehicle (called the absorbing vehicle) upstream of the wave, and improves traffic performances such as fuel consumption and collision risk. However, the deceleration of the absorbing vehicle causes trailing vehicles to slow down, generating secondary shock waves that undermine these benefits. This study proposes a method to suppress se…

Crosslisted article(s) found for astro-ph.HE. https://arxiv.org/list/astro-ph.HE/new
[1/1]:
- Foreground and internal free-free absorption in particle-accelerating colliding-wind binaries : I...
M. Tasseroul, M. De Becker, A. B Blanco, P. Benaglia, S. del Palacio

Dust Attenuation of Lyman-Werner Feedback: Reassessing Early Super Massive Black Holes Seed Formation
Bisweswar Sen
https://arxiv.org/abs/2509.11111 https://

Dust Attenuation of Lyman-Werner Feedback: Reassessing Early Super Massive Black Holes Seed Formation
We investigate the impact of dust shielding on Lyman-Werner (LW) radiation fields and its implications for supermassive black hole (SMBH) seed formation at high redshift. Using an updated version of the GAMETE/QSOdust semi-analytical model, we implement a simple dust shielding prescription that accounts for the absorption of LW photons by dust grains. We find that even modest dust enrichment can significantly reduce the effective LW radiation field, allowing H2 cooling to persist in regions pre…

Quantifying the Impact of Lunar and Planetary Occultation on Experimental Global 21 cm Cosmology
Joe H. N. Pattison, Dominic J. Anstey, Eloy de Lera Acedo
https://arxiv.org/abs/2509.11679

Quantifying the Impact of Lunar and Planetary Occultation on Experimental Global 21 cm Cosmology
The global 21 cm signal from the hyperfine transition of cosmic atomic hydrogen is theorised to track the state of the early Universe via the analysis of its absorption and emission with respect to the radio background. Detecting this signal has been a challenge for astronomers since it was first postulated due to the presence of strong galactic foregrounds obfuscating the transition. Forward modelling techniques that aim to simulate and then remove these foregrounds have been suggested as a wo…

Absence of higher than 6-fold coordination in glassy $GeO_{2}$ up to 158 GPa revealed by X-ray absorption spectroscopy
Jo\~ao Elias F. S. Rodrigues, Angelika D. Rosa, Emin Mijit, Tetsuo Irifune, Gaston Garbarino, Olivier Mathon, Raffaella Torchio, Max Wilke
https://arxiv.org/abs/2507.04076…

Absence of higher than 6-fold coordination in glassy $GeO_{2}$ up to 158 GPa revealed by X-ray absorption spectroscopy
Simple binary oxide glasses can exhibit a compression behavior distinct from that of their crystalline counterparts. In this study, we employed high-pressure X-ray absorption spectroscopy coupled to the diamond anvil cell to investigate in detail local structural changes around Ge in glassy $GeO_{2}$ up to 158 GPa. We conducted four independent runs, both with and without pressure-transmitting media. Up to 30 GPa, we observed no significant influence of the pressure medium on the pressure depen…

Determination of the $\phi$-meson production process and its absorption cross section via directed flow
Jan Steinheimer, Tom Reichert, Marcus Bleicher
https://arxiv.org/abs/2507.19289

Determination of the $ϕ$-meson production process and its absorption cross section via directed flow
We show that the directed flow of $ϕ$-mesons in Au+Au collisions at $\sqrt{s_{NN}}=3$ GeV, is sensitive on production and the absorption cross section of the $ϕ$ in a nuclear medium. This provides a new observable to constrain the in-medium properties of the $ϕ$ which is independent of its absolute production rate. It is shown that the STAR data disfavor any significant $ϕ$-N absorption in dense nuclear matter and are consistent with a very small cross section of the $ϕ$ comparable to the …

Non-equilibrium Dynamics of Three-Level Absorption Refrigerator at Third-Order Liouvillian Exceptional Points
Jingyi Gao, Naomichi Hatano
https://arxiv.org/abs/2507.18261 https:…

Non-equilibrium Dynamics of Three-Level Absorption Refrigerator at Third-Order Liouvillian Exceptional Points
We analyze the influence of Liouvillian exceptional points (LEPs) in the three-level quantum absorption refrigerator, putting emphasis on the non-equilibrium process before the convergence to the steady state. We search for the second-order and third-order LEPs in the system with two types of couplings. Focusing on the third-order LEPs, we analyze the damping of the system state in the long term analytically and numerically. In addition, we analyze the damping of heat currents and the influence…

Optical and Near-Infrared Spectroscopy of the Outbursting Comet 12P/Pons-Brooks
Ruining Zhao, Bin Yang, Michael S. P. Kelley, Silvia Protopapa, Aigen Li, Yang Huang, Jifeng Liu
https://arxiv.org/abs/2507.03247

Optical and Near-Infrared Spectroscopy of the Outbursting Comet 12P/Pons-Brooks
We present optical and near-infrared (NIR) observations of the outbursting, Halley-type comet 12P/Pons-Brooks. Three NIR spectra were obtained during two outbursts in October and November 2023, with the 3-meter Infrared Telescope Facility and the Palomar 200-inch Telescope, respectively. The NIR spectra exhibited absorption features at 1.5 and 2.0 $μ$m, consistent with the diagnostic absorption bands of water ice, superimposed on a red dust-scattering continuum. We find that the absorption ban…

LATIS: Comparing Galaxy and IGM Tomography Maps as Tracers of Large-scale Structure and Protoclusters at $z \sim 2.5$
Andrew B. Newman, Nima Chartab, Mahdi Qezlou, Gwen C. Rudie, Guillermo A. Blanc, Daniel D. Kelson, Simeon Bird, Caitlin Casey, Enrico Congiu, Olga Cucciati, Denise Hung, Brian C. Lemaux, Victoria P\'erez, Jorge Zavala
https://

LATIS: Comparing Galaxy and IGM Tomography Maps as Tracers of Large-scale Structure and Protoclusters at $z \sim 2.5$
We investigate the consistency of intergalactic medium (IGM) tomography and galaxy surveys as tracers of the cosmic web and protoclusters at $z \sim 2.5$. We use maps from the Ly$α$ Tomography IMACS Survey (LATIS), which trace the distributions of Lyman-break galaxies (LBGs) and IGM Ly$α$ absorption on $\simeq 4$ $h^{-1}$ cMpc scales within the same large volume. Overall, the joint distribution of IGM absorption and LBG density is well constrained and accurately described by a simple physical…

Photon Absorption Remote Sensing (PARS): Comprehensive Absorption Imaging Enabling Label-Free Biomolecule Characterization and Mapping
Benjamin R. Ecclestone, James A. Tummon Simmons, James E. D. Tweel, Deepak Dinakaran, Parsin Haji Reza
https://arxiv.org/abs/2506.20069

Photon Absorption Remote Sensing (PARS): Comprehensive Absorption Imaging Enabling Label-Free Biomolecule Characterization and Mapping
Label-free optical absorption microscopy techniques continue to evolve as promising tools for label-free histopathological imaging of cells and tissues. However, critical challenges relating to specificity and contrast, as compared to current gold-standard methods continue to hamper adoption. This work introduces Photon Absorption Remote Sensing (PARS), a new absorption microscope modality, which simultaneously captures the dominant de-excitation processes following an absorption event. In PARS…

Isentropic processes for axisymmetric Black Holes
Nitesh K. Dubey, Sanved Kolekar
https://arxiv.org/abs/2507.08547 https://arxiv.org/…

Isentropic processes for axisymmetric Black Holes
We demonstrate that the isentropic absorption of a classical charged test particle is classically forbidden for all 3+1 dimensional stationary, non-extremal, axisymmetric black holes in any diffeomorphism invariant theory of gravity. This result is derived purely from the near-horizon geometry and thermodynamic properties of the black hole spacetime, independent of the specific gravitational theory. We further consider the Kerr-Newman black hole in general relativity and analyze within the semi…

Longitudinal spin current absorption in bilayers composed of ferromagnetic and highly-resistive non-magnetic layers
Sosuke Hori, Kohei Ueda, Junichi Shiogai, Jobu Matsuno
https://arxiv.org/abs/2509.07390

Longitudinal spin current absorption in bilayers composed of ferromagnetic and highly-resistive non-magnetic layers
Spin Hall magnetoresistance (SMR) is an intriguing spin-dependent transport phenomenon in bilayers consisting of non-magnetic and magnetic layers. Here, we report on the influence of longitudinal spin current absorption by the magnetic layer on SMR in bilayers composed of Co$_{20}$Fe$_{60}$B$_{20}$ (CoFeB) and epitaxial SrIrO$_{3}$, where SrIrO$_{3}$ is used as a highly-resistive spin current source. We observed a clear SMR signal and an enhancement in the SMR ratio with increasing CoFeB layer …

Forward and inverse problems of a semilinear transport equation
Kui Ren, Yimin Zhong
https://arxiv.org/abs/2509.06183 https://arxiv.org/pdf/2509.06183

Forward and inverse problems of a semilinear transport equation
We study forward and inverse problems for a semilinear radiative transport model where the absorption coefficient depends on the angular average of the transport solution. Our first result is the well-posedness theory for the transport model with general boundary data, which significantly improves previous theories for small boundary data. For the inverse problem of reconstructing the nonlinear absorption coefficient from internal data, we develop stability results for the reconstructions and u…

Theoretical calculation of finite-temperature X-ray absorption fine structure: application to sodium K-edge in NaCl
Philipp H\"onicke, Yves Kayser, Pouya Partovi-Azar
https://arxiv.org/abs/2509.02206

Theoretical calculation of finite-temperature X-ray absorption fine structure: application to sodium K-edge in NaCl
We present a comprehensive computational framework for reproducing the full X-ray absorption fine structure (XAFS) through quantum-chemical simulations. The near-edge region is accurately captured using an efficient implementation of time-dependent density-functional perturbation theory applied to core excitations, while ab initio molecular dynamics provides essential sampling of core-excitation energies and interatomic distance distributions for interpreting extended X-ray absorption fine stru…

X-ray Transmission Through Photoionized Gas with Moderate Thomson Optical Depth
Taya Govreen-Segal, Ehud Nakar, Eliot Quataert
https://arxiv.org/abs/2509.08119 https://

X-ray Transmission Through Photoionized Gas with Moderate Thomson Optical Depth
We model the absorption of X-rays by gas obscuring the source and photoionized by it. We consider a broad range of column densities, including both Thomson-thin and Thomson-thick media. For the Thomson thin regime, we derive a simple criterion, based on the source luminosity and spectrum and the medium radius and column density, that distinguish between the following cases: (i) The absorption can be modeled well by a neutral medium; (ii) The radiation ionizes its way through the medium and no a…

THOR: a GPU-accelerated and MPI-parallel radiative transfer code
Chris Byrohl, Dylan Nelson
https://arxiv.org/abs/2507.11603 https://…

THOR: a GPU-accelerated and MPI-parallel radiative transfer code
Emission and absorption line features are important diagnostics for the physics underlying extragalactic astronomy. The interpretation of observed signatures involves comparing against forward modeled spectra from galaxy formation simulations as well as more simplified geometries, while including the complex scattering radiative transfer (RT) of resonant emission lines. Here, we present thor, a modern C++ radiative transfer code focused initially on resonant emission lines. thor is a high-perfo…

Optical absorption of a Cu$_2$SnS$_3$ (CTS) layer trapped by metallic thin films in multilayer configuration
Le Tri Dat, Nguyen Duy Vy
https://arxiv.org/abs/2508.04113 https://

Optical absorption of a Cu$_2$SnS$_3$ (CTS) layer trapped by metallic thin films in multilayer configuration
Coating and reflecting thin films for energy harvesting purposes are interesting topics in both theoretical and experimental research. The thin film could help to enhance the absorption of the system via its specific optical properties depending on the optical wavelength and the stacked layer thickness. Here, by using Maxwell's equations for the electromagnetic fields penetrating thin films, we examined in detail the absorption of a CTS layer coated by nanometer-thick thin films of several mate…

Progress toward a demonstration of high contrast imaging at ultraviolet wavelengths
Kyle Van Gorkom, Ramya M. Anche, Christopher B. Mendillo, Jessica Gersh-Range, G. C. Hathaway, Saraswathi Kalyani Subramanian, Justin Hom, Tyler D. Robinson, Mamadou N'Diaye, Nikole K. Lewis, Bruce Macintosh, Ewan S. Douglas
https://arxiv.org/abs/2509.0…

Progress toward a demonstration of high contrast imaging at ultraviolet wavelengths
NASA's Habitable Worlds Observatory (HWO) aims to achieve starlight suppression to the $10^{-10}$ level for the detection and spectral characterization of Earth-like exoplanets. Broadband ozone absorption features are key biosignatures that appear in the 200-400nm near-ultraviolet (UV) regime. Extending coronagraphy from visible wavelengths to the UV, however, brings with it a number of challenges, including tighter requirements on wavefront sensing and control, optical surface quality, scatter…

Empirical Calibration of Na I D and Other Absorption Lines as Tracers of High-Redshift Neutral Outflows
Lorenzo Moretti, Sirio Belli, Gwen C. Rudie, Andrew B. Newman, Minjung Park, Amir H. Khoram, Nima Chartab, Darko Donevski
https://arxiv.org/abs/2507.07160

Empirical Calibration of Na I D and Other Absorption Lines as Tracers of High-Redshift Neutral Outflows
Recent JWST observations of massive galaxies at z > 2 have detected blueshifted absorption in Na I D and other resonant absorption lines, indicative of strong gas outflows in the neutral phase. However, the measured mass outflow rates are highly uncertain because JWST observations can only probe the column density of trace elements such as sodium, while most of the gas is in the form of hydrogen. The conversion between the column density of sodium and that of hydrogen is based on observations o…

X-ray absorption lines in FUV-detected quasars: II. Cosmological density and properties of the missing baryons
Massimiliano Bonamente, David Spence, Jussi Ahoranta, Nastasha Wijers, Toni Tuominen, Jelle De Plaa
https://arxiv.org/abs/2507.21719

X-ray absorption lines in FUV-detected quasars: II. Cosmological density and properties of the missing baryons
This paper presents constraints on the cosmological density of baryons from a systematic search for O VII and O VIII absorption lines in the XMM-Newton and Chandra X-ray spectra of 51 background sources. The search is based on far ultra-violet redshift priors from HST and FUSE, and it has resulted in the identification of 34 possible O VII and O VIII absorption-line systems at the 99% confidence level, out of a search in 1,224 systems with fixed redshift priors. Of these, 7 O VII and 8 O VIII s…

Power coupled to the slow wave resonance cone in cold plasma
Wouter Tierens
https://arxiv.org/abs/2509.10276 https://arxiv.org/pdf/2509.10276

Power coupled to the slow wave resonance cone in cold plasma
We consider the power coupled to the plasma from a cylindrical source emitting resonance cones, propagative slow waves which exist in low density magnetized plasmas when the signs of the Stix parameters S and P differ. In this work, we calculate this power for the first time for any collisionality, and show that it remains finite in the cold collisionless limit, even as the radiofrequency electric field itself, and the associated power absorption density, is singular. We give the main parameter…

Temperature behavior of optical absorption spectra in HfO2 thin films
A. O. Shilov, S. S. Savchenko, A. S. Vokhmintsev, V. A. Gritsenko, I. A. Weinstein
https://arxiv.org/abs/2509.07419

Temperature behavior of optical absorption spectra in HfO2 thin films
Hafnium dioxide, also known as hafnia, is an extremely sought-after material in opto- and nanoelectronics for creating optical coatings and various functional media to have stable performance characteristics under varying thermal operating conditions. In this paper, we have investigated the behavior of the optical properties of hafnia thin films exhibiting an amorphous structure in a wide temperature range of 7-296 K. For the first time we have examined the temperature effects in the energy gap…

Crosslisted article(s) found for physics.optics. https://arxiv.org/list/physics.optics/new
[1/1]:
- Attosecond Transient Absorption Study of Coherent Hole Oscillation in Ar
Chakraborty, Alarcon, McDonnell, Hauser, Shalaby, Biswas, Wood, Golubev, Sandhu

Effects of inhomogenuity and anisotropy of radiation field on production and absorption of high energy radiation
J. Sitarek
https://arxiv.org/abs/2508.00457 https://

Effects of inhomogenuity and anisotropy of radiation field on production and absorption of high energy radiation
We investigate the geometrical effects affecting the production and absorption of gamma-ray radiation emitted in inverse Compton scattering in the synchrotron-self-Compton process. We evaluate the effect of the anisotropy of the radiation field seen by the scattering electrons homogeneously distributed in the emission region. Next, we also consider inhomogeneous distribution of electrons and investigate the effect of it in the spherically symmetric emission region. We also study a cylindrical s…

Kinematics of Circumgalactic O VI Gas and Disk Rotation of $z\approx0.2$ Star-forming Galaxies
Stephanie H. Ho, Crystal L. Martin, Hasti Nateghi, Glenn G. Kacprzak, Jonathan Stern
https://arxiv.org/abs/2507.11664

Kinematics of Circumgalactic O VI Gas and Disk Rotation of $z\approx0.2$ Star-forming Galaxies
Quasar sightline observations reveal that low-ionization-state gas corotates with the galaxy disk and often at sub-centrifugal velocities, suggesting that the gas is spiraling towards the galaxy disk. However, while observations ubiquitously detect O VI absorption around low-redshift, $\sim L^*$ star-forming galaxies, the relationship between O VI and the galaxy disk, especially the kinematics, is not well-established. This work focuses on the O VI kinematics and its comparison with that of the…

Can high-redshift AGN observed by JWST explain the EDGES absorption signal?
Alexandra Nelander, Christopher Cain, Jordan C J DSilva, Peter H Sims, Rogier A Windhorst, Judd D Bowman
https://arxiv.org/abs/2507.21230

Can high-redshift AGN observed by JWST explain the EDGES absorption signal?
The Experiment to Detect the Global Epoch of Reionization 21 cm Signal (EDGES) has reported evidence for an absorption feature in the sky-averaged radio background near 78 MHz. A cosmological interpretation of this signal corresponds to absorption of 21 cm photons by neutral hydrogen at $z \sim 17$. The large depth of the signal has been shown to require an excess radio background above the CMB and/or non-standard cooling processes in the IGM. Here, we explore the plausibility of a scenario in …

Performance Benchmarking of Machine Learning Models for Terahertz Metamaterial Absorber Prediction
Nafisa Anjum, Robiul Hasan
https://arxiv.org/abs/2508.08611 https://

Performance Benchmarking of Machine Learning Models for Terahertz Metamaterial Absorber Prediction
This study presents a polarization-insensitive ultra-broadband terahertz metamaterial absorber based on vanadium dioxide (VO2) and evaluates machine learning methods for predicting its absorption performance. The structure consists of a VO2 metasurface, a MF2 dielectric spacer, and a gold ground plane. It achieves more than 90% absorption between 5.72 and 11.11 THz, covering a 5.38 THz bandwidth with an average absorptance of 98.15%. A dataset of 9,018 samples was generated from full-wave simul…

COS-EDGES: Co-rotation and Kinematic Stratification of the Multi-Phase CGM Around Edge-On Galaxies
Glenn G. Kacprzak, Benjamin D. Oppenheimer, Nikole M. Nielsen, Antonia Fernandez-Figueroa, Michael T. Murphy, Rebecca J. Allen, Tania M. Barone, Sameer, Christopher W. Churchill, Joseph N. Burchett, Kaustubh R. Gupta, Jane C. Charlton, Caleb B. Platukis

COS-EDGES: Co-rotation and Kinematic Stratification of the Multi-Phase CGM Around Edge-On Galaxies
We present the first results from the COS-EDGES survey, targeting the kinematic connection between the ISM and multi-phase circumgalactic medium (CGM) in nine isolated, edge-on galaxies at z~0.2, each probed along its major axis by a background quasar at impact parameters of 13-38kpc. Using VLT/UVES and HST/COS quasar spectra, we analyse MgI, MgII, HI, CII, CIII, and OVI absorption relative to galaxy rotation curves from Keck/LRIS and Magellan/MagE spectra. We find that at lower $D/R_{vir}$ ($D…

Interplay of vibrational, electronic, and magnetic states in CrSBr
Daria I. Markina, Priyanka Mondal, Lukas Krelle, Sai Shradha, Mikhail M. Glazov, Regine von Klitzing, Kseniia Mosina, Zdenek Sofer, Bernhard Urbaszek
https://arxiv.org/abs/2509.10267

Interplay of vibrational, electronic, and magnetic states in CrSBr
The van der Waals antiferromagnet CrSBr exhibits coupling of vibrational, electronic, and magnetic degrees of freedom, giving rise to distinctive quasi-particle interactions. We investigate these interactions across a wide temperature range using polarization-resolved Raman spectroscopy at various excitation energies, complemented by optical absorption and photoluminescence excitation (PLE) spectroscopy. Under 1.96 eV excitation, we observe pronounced changes in the A$_g^1$, A$_g^2$, and A$_g^3…

First detection of ices in intermediate-mass young stellar objects beyond the Milky Way
Guido De Marchi, Nolan Habel, Margaret Meixner, Katia Biazzo, Giovanna Giardino, Elena Sabbi, Ciaran Rogers, Jeroen Jaspers, Massimo Robberto, Peter Zeidler, Olivia C. Jones, Katja Fahrion, Alec S. Hirschauer, Charles D. Keyes, David R. Soderblom, Laura Lenkic, Omnarayani Nayak, Bernhard Brandl

First detection of ices in intermediate-mass young stellar objects beyond the Milky Way
Using NIRSpec on JWST, we studied a sample of 15 intermediate-mass (1.8-4.1 Msun) young stellar objects (YSOs) previously identified with MIRI photometry in the low-metallicity NGC 346 star-forming cluster in the Small Magellanic Cloud (SMC). All objects, observed in the 1.7-5.3 micron range, show strong hydrogen recombination lines in the Paschen, Brackett, Pfund, and Humphreys series, confirming their very young ages. The spectra of 11 YSOs show prominent absorption bands from the three most …

Sensitive and accurate femtosecond pulse characterization via two-photon absorption in Fabry-P\'erot laser diodes
Adrian F. Chlebowski, Jakub Mnich, Lukasz A. Sterczewski, Jaroslaw Z. Sotor
https://arxiv.org/abs/2507.03978

Sensitive and accurate femtosecond pulse characterization via two-photon absorption in Fabry-Pérot laser diodes
Semiconductor lasers offer native bifunctionality enabling coherent light emission and linear photodetection. They can also operate as sensitive two-photon absorption detectors due to the third-order nonlinearity of the heterostructure constituting the active region. The strong two-photon response at room temperature is highly desired in ultrafast optics, where such detectors are used for interferometric characterization of femtosecond light pulses for shape and duration. Another niche is pulse…

Infrared Spectroradiometry of Lithium Benzoate from 21 to 235 THz
Yoshitaka Okuyama, Youichi Ishikawa
https://arxiv.org/abs/2509.11643 https://arxiv.org/pd…

Infrared Spectroradiometry of Lithium Benzoate from 21 to 235 THz
This paper presents an extensive survey of the thermal radiation properties of lithium benzoate. We heated the sample from 313 to 553 K, just below the melting point, while performing an infrared spectroradiometry with an FT-IR spectrometer from 21 to 235 THz (700-7800 cm$^{-1}$). We have provided a detailed analysis of the infrared spectrum data and a comparison of the absorption spectrum of the same sample. It turned out that the recorded spectra are not only different from ordinary absorptio…

XANES absorption spectra of penta-graphene and penta-SiC2 with different terminations: a computational study
Andrea Pedrielli, Tommaso Morresi, Simone Taioli
https://arxiv.org/abs/2508.00704

XANES absorption spectra of penta-graphene and penta-SiC2 with different terminations: a computational study
In recent research, penta-graphene and penta-SiC2 have emerged as innovative 2D materials consisting exclusively of pentagons. However, there is still a significant gap in the theoretical characterization of these materials, which hinders progress in their synthesis and potential technological applications. This study aims to close this gap by investigating the X-ray absorption near-edge spectroscopy (XANES) of these materials through ab initio calculations. In particular, we analyze the XANES …

Re-examination of the CO absorption line in the M87 nucleus
Norita Kawanaka, Hiroshi Nagai, Yutaka Fujita
https://arxiv.org/abs/2508.03015 https://arxiv.or…

Re-examination of the CO absorption line in the M87 nucleus
We analyzed the archival ALMA data of the nuclear region of M87 and evaluate the molecular gas content from the CO(2--1) absorption line. We found an enigmatic variability in the absorption line depth between two epochs separated by only two months. We reexamined the dataset used in the analysis and found that the bandpass calibration source within the same dataset also revealed a similar absorption line structure. Furthermore, we observed a rise in the system noise temperature spectrum. We con…

Label-Free Whole Slide Virtual Multi-Staining Using Dual-Excitation Photon Absorption Remote Sensing Microscopy
James E. D. Tweel, Benjamin R. Ecclestone, James A. Tummon Simmons, Parsin Haji Reza
https://arxiv.org/abs/2509.05085

Label-Free Whole Slide Virtual Multi-Staining Using Dual-Excitation Photon Absorption Remote Sensing Microscopy
Histochemical staining is essential for visualizing tissue architecture and cellular morphology but is destructive and limited by the availability of tissue for multiple stains. Virtual staining with label-free microscopy offers a non-destructive alternative, enabling multiple stains to be generated from the same section while reducing stain variability and preserving tissue for downstream assays. Here, a new dual-excitation Photon Absorption Remote Sensing (PARS) system is presented, represent…

Electronic structure and defect properties of Bi-doped GaN: origins of photoluminescence and optical absorption
Yujie Liu, Ishtiaque Ahmed Navid, Zetian Mi, Emmanouil Kioupakis
https://arxiv.org/abs/2507.01346

Electronic structure and defect properties of Bi-doped GaN: origins of photoluminescence and optical absorption
Extreme lattice-mismatched III-V nitrides, such as Bi-incorporated GaN, have been realized experimentally thanks to recent advances in epitaxial growth and characterization techniques. However, theoretical insights into defect-related optical absorption and emission phenomena in these materials remain scarce. Here, we apply hybrid density functional theory to systematically explore the role of substitutional bismuth atoms on both cationic $\mathrm{Bi_{Ga}}$ and anionic $\mathrm{Bi_{N}}$ sites i…

An analysis of derivative absorption spectroscopy of multiferroic bismuth ferrite materials
Ramachandran Balakrishnan
https://arxiv.org/abs/2506.21229 http…

An analysis of derivative absorption spectroscopy of multiferroic bismuth ferrite materials
The probability density function (PDF) and cumulative density function (CDF) of bulk BiFeO3, nanostructured BiFeO$_3$, and thick film of BiFeO$_{2.85}$ were studied in detail based on their experimental absorption data. The goal of this study was to investigate the electronic transitions and the Urbach tail band in three samples of the magnetoelectric multiferroic BiFeO$_3$. The PDF and CDF functions were derived from the absorption data of these substances in the UV-visible-NIR region of light…

BASS. XLIX. Characterization of highly luminous and obscured AGNs: local X-ray and [NeV]$\lambda$3426 emission in comparison with the high-redshift Universe
Alessandro Peca, Michael J. Koss, Kyuseok Oh, Claudio Ricci, Benny Trakhtenbrot, Richard Mushotzky, Ezequiel Treister, C. Megan Urry, Andrealuna Pizzetti, Kohei Ichikawa, Alessia Tortosa, Federica Ricci, Matilde Signorini, Darshan Kakkad, Chin-Shin Chang, Giovanni Mazzolari, Turgay Caglar, Macon Magno, Ignacio del Moral-Castro, Pet…

BASS. XLIX. Characterization of highly luminous and obscured AGNs: local X-ray and [NeV]$λ$3426 emission in comparison with the high-redshift Universe
We present a detailed analysis of the most luminous and obscured Active Galactic Nuclei (AGNs) detected in the ultra-hard X-ray band (14-195 keV) by Swift/BAT. Our sample comprises 21 X-ray luminous (log $L_X/{\rm erg\,s^{-1}}>44.6$, 2-10 keV) AGNs at $z<0.6$, optically classified as Seyfert 1.9-2. Using NuSTAR, XMM-Newton, Suzaku, and Chandra, we constrain AGN properties such as absorption column density $N_H$, photon index $Γ$, intrinsic $L_X$, covering factor, and iron K$α$ equivalent widt…

LATIS: A Sample of IGM-selected Protoclusters and Protogroups at $z \sim 2.5$
Andrew B. Newman, Mahdi Qezlou, Gwen C. Rudie, Nima Chartab, Guillermo A. Blanc, Daniel D. Kelson, Simeon Bird, Caitlin Casey, Enrico Congiu, Olga Cucciati, Denise Hung, Brian C. Lemaux, Victoria P\'erez, Jorge Zavala
https://arxiv.org/abs/2507.109…

LATIS: A Sample of IGM-selected Protoclusters and Protogroups at $z \sim 2.5$
The Ly$α$ Tomography IMACS Survey (LATIS) has produced large 3D maps of the intergalactic medium (IGM), providing a new window on the cosmic web at $z\sim2.5$. A key advantage of Ly$α$ tomography is that it enables the discovery of overdense regions without the need to detect their galaxy members in spectroscopic surveys, circumventing possible selection biases. We use these maps to identify 37 IGM-selected overdensities as regions of strong and spatially coherent Ly$α$ absorption. Simulatio…

Enhanced intraband absorption in two-step photon upconversion solar cells with a double-tunnel-junction structure
Koichiro Matsuzawa, Shigeo Asahi, Takashi Kita
https://arxiv.org/abs/2509.04195

Enhanced intraband absorption in two-step photon upconversion solar cells with a double-tunnel-junction structure
Two-step photon upconversion solar cells (TPU-SCs) belong to the class of solar cells that in principle can exceed the Shockley--Queisser limit for single-junction solar cells. A TPU-SC basically consists of a wide-gap and a narrow-gap semiconductor layer, where intraband absorption of infrared (IR) photons by electrons accumulated at the conduction-band-edge discontinuity leads to an increase in the output current and voltage. This IR-induced upconversion process enables a better utilization o…

Coherent perfect absorption and lasing in bimodal Fabry-P\'erot interferometers
Dmitry A. Bykov, Evgeni A. Bezus, Leonid L. Doskolovich
https://arxiv.org/abs/2509.01356 http…

Coherent perfect absorption and lasing in bimodal Fabry-Pérot interferometers
Bimodal Fabry-Pérot interferometer is a model generalizing the conventional Fabry-Pérot interferometer, in which not one but two kinds of waves propagate between the interfaces. Here, we study coherent perfect absorption (CPA) and lasing at threshold in bimodal Fabry-Pérot interferometers. We show that CPA and lasing appear only in certain "allowed" regions in the parameter space, which, as we demonstrate, are described by closed-form inequalities imposed on the elements of the scattering ma…

A fast machine learning tool to predict the composition of astronomical ices from infrared absorption spectra
Andr\'es Meg\'ias, Izaskun Jim\'enez-Serra, Fran\c{c}ois Dulieu, Julie Vitorino, Bel\'en Mat\'e, David Ciudad, Will R. M. Rocha, Marcos Mart\'inez Jim\'enez, Jacobo Aguirre
https://arxiv.org/abs/2509.043…

A fast machine learning tool to predict the composition of astronomical ices from infrared absorption spectra
Current observations taken by James Webb Space Telescope (JWST) allow us to observe the absorption features of icy mantles that cover interstellar dust grains, which are mainly composed of $\mathrm{H_2O}$, $\mathrm{CO}$, and $\mathrm{CO_2}$, along with other minor species. Thanks to its sensitivity and spectral resolution, JWST has the potential to observe ice features towards hundreds of sources at different stages along the process of star formation. However, identifying the spectral features…