Tootfinder

FS-SAM2: Adapting Segment Anything Model 2 for Few-Shot Semantic Segmentation via Low-Rank Adaptation
Bernardo Forni, Gabriele Lombardi, Federico Pozzi, Mirco Planamente
https://arxiv.org/abs/2509.12105

FS-SAM2: Adapting Segment Anything Model 2 for Few-Shot Semantic Segmentation via Low-Rank Adaptation
Few-shot semantic segmentation has recently attracted great attention. The goal is to develop a model capable of segmenting unseen classes using only a few annotated samples. Most existing approaches adapt a pre-trained model by training from scratch an additional module. Achieving optimal performance with these approaches requires extensive training on large-scale datasets. The Segment Anything Model 2 (SAM2) is a foundational model for zero-shot image and video segmentation with a modular des…

Scaling of thin wire cylindrical compression after 100 fs Joule surface heating with material, diameter and laser energy
L. Yang, M. -L. Herbert, C. B\"ahtz, V. Bouffetier, E. Brambrink, T. Dornheim, N. Fefeu, T. Gawne, S. G\"ode, J. Hagemann, H. H\"oeppner, L. G. Huang, O. S. Humphries, T. Kluge, D. Kraus, J. L\"utgert, J. -P. Naedler, M. Nakatsutsumi, A. Pelka, T. R. Preston, C. Qu, S. V. Rahul, R. Redmer, M. Rehwald, L. Randolph, J. J. Santos, M. \v{S}m\'id, …

Scaling of thin wire cylindrical compression after 100 fs Joule surface heating with material, diameter and laser energy
We present the first systematic experimental validation of return-current-driven implosion scaling in micrometer-sized wires irradiated by femtosecond laser pulses. Employing XFEL-based imaging with sub-micrometer spatial and femtosecond temporal resolution, supported by hydrodynamic and particle-in-cell simulations, we reveal how return current density depends precisely on wire diameter, material properties, and incident laser energy. We identify deviations from simple theoretical predictions …

from my link log —
fs_usage: see filesystem activity on Mac OS X.
https://til.simonwillison.net/macos/fs-usage
saved 2025-07-10 htt…

Using fs_usage to see what files a process is using
Today I wanted to figure out where the vercel CLI tool on my Mac kept its authentication tokens.

I've sent out a funding application to OSFF for Intel ME tooling.
🥳
I had started an Intel ME file system parser for recent and current versions:
https://github.com/fiedka/me_fs_rs 👈🧐
Then I realized how much overlap there is between this, MEAnalyzer, the long unmaintained me_clean…

GitHub - fiedka/me_fs_rs: Intel ME filesystem parser written in Rust :crab:
Intel ME filesystem parser written in Rust :crab:. Contribute to fiedka/me_fs_rs development by creating an account on GitHub.

📗 Cornford, F. M. (2023). Antes y Después de Sócrates (Edición de acceso abierto). [Publicación original: 1932].
https://archive.org/details/cornford-f.-m.-antes-y-despues-de-socrates-epl-fs-1932-2023
En "Antes y Después de

Cornford, F. M. Antes Y Después De Sócrates [EPL FS] [1932] [2023] : F. M. Cornford : Free Download, Borrow, and Streaming : Internet Archive
Edición digital ePubLibre, 2023. Ed. original 1932. Acceso abierto.

Top tip for improving openSUSE performance on somwhat-constrained systems (e.g. Ryzen 7 3700C/16GB RAM ex-Chromebook): get rid of btrfs. The constant fs housekeeping tasks grind it to a halt, and it's not the quickest to begin with. This thing absolutely FLIES with XFS. Oh no, no snapshots, guess I'd better just treat it like every previous Linux system I've ever had :P

FS-Diff: Semantic guidance and clarity-aware simultaneous multimodal image fusion and super-resolution
Yuchan Jie, Yushen Xu, Xiaosong Li, Fuqiang Zhou, Jianming Lv, Huafeng Li
https://arxiv.org/abs/2509.09427

FS-Diff: Semantic guidance and clarity-aware simultaneous multimodal image fusion and super-resolution
As an influential information fusion and low-level vision technique, image fusion integrates complementary information from source images to yield an informative fused image. A few attempts have been made in recent years to jointly realize image fusion and super-resolution. However, in real-world applications such as military reconnaissance and long-range detection missions, the target and background structures in multimodal images are easily corrupted, with low resolution and weak semantic inf…

from my link log —
Using LXCFS together with Podman.
https://www.die-welt.net/2025/06/using-lxcfs-together-with-podman/
saved 2025-06-25

Unveiling the electronic structure of the charge density wave and topological semimetal TaTe4 through high-field magnetotransport measurements
D. Silvera-Vega, J. Rojas-Castillo, E. Herrera-Vasco, E. Ramos-Rodr\'iguez, A. F. Santander-Syro, J. A. Galvis, B. Uribe, R. Gonz\'alez-Hern\'andez, A. C. Garc\'ia-Castro, P. Giraldo-Gallo
http…

Unveiling the electronic structure of the charge density wave and topological semimetal TaTe4 through high-field magnetotransport measurements
Understanding the interplay between topology and correlated electron states is central to the study of quantum materials. TaTe$_4$, a charge density wave (CDW) compound predicted to host topological phases, offers a platform to explore this interplay. Here, we report a comprehensive study of the Fermi surface (FS) of TaTe$_4$ via high-field magnetotransport measurements and density functional theory (DFT) calculations. Using three distinct field-current configurations, we resolve four out of fi…

High contrast few-cycle frontend with hybrid amplification for petawatt-class lasers
Roland S. Nagymih\'aly, Mikhail Kalashnikov, Levente Lehotai, Viktor Pajer, J\'anos Bohus, N\'ora Csernus-Luk\'acs, J\'anos Csontos, Szabolcs T\'oth, Bal\'azs Tari, Ignas Balciunas, Ernestas Kucinskas, Tomas Stanislauskas, \'Ad\'am B\"orzs\"onyi

High contrast few-cycle frontend with hybrid amplification for petawatt-class lasers
We present a 10 mJ-class laser system for seeding petawatt-class Ti:Sa lasers based on a hybrid, femtosecond optical parametric and negatively chirped Ti:Sa-based amplification architecture. Output pulses with 13 mJ energy, 14.4 fs transform limited duration, and high spatio-spectral quality are reached at 100 Hz repetition rate centered at 788 nm wavelength. By compressing 1 mJ energy with bulk glass and positively chirped mirrors, a pulse duration of 15.5 fs is measured. The intensity contras…

Energy Bunching from Sub-Cycle Ionization Injection in Laser Wakefield Acceleration
A. Angella, E. L\"ofquist, C. Gustafsson, V. Poulain, F. D'Souza, C. Guo, A. Persson, P. Eng-Johnsson, C. -G. Wahlstr\"om, O. Lundh
https://arxiv.org/abs/2508.10829

Energy Bunching from Sub-Cycle Ionization Injection in Laser Wakefield Acceleration
We report the first experimental observation of carrier-envelope phase-driven energy bunching in laser wakefield acceleration. Using a few-cycle (~9 fs), multi-terawatt laser pulse and ionization injection in a helium-nitrogen gas mixture, we observe electron spectra composed of multiple quasi-monoenergetic peaks with regular narrow energy spacing. This comb structure arises from intermittent injection from successive half-cycles of the laser field, enabled by the evolving carrier-envelope phas…

Sub-5-fs compression and synchronization of relativistic electron bunches enabled by a high-gradient $\alpha$-magnet and low-jitter photoinjector
Yining Yang, Zhiyuan Wang, Peng Lv, Baiting Song, Pengwei Huang, Yanqing Jia, Zhuoxuan Liu, Lianmin Zheng, Wenhui Huang, Pietro Musumeci, Chuanxiang Tang, Renkai Li
https://arxiv.org/abs/2508.039…

Sub-5-fs compression and synchronization of relativistic electron bunches enabled by a high-gradient $α$-magnet and low-jitter photoinjector
Generating high-brightness relativistic electron bunches with few-femtosecond duration, while simultaneously achieving few-fs synchronization with ultrafast lasers, remains an outstanding challenge at the frontier of accelerator physics and ultrafast science. In this Letter, we present the beam physics and experimental demonstration of a new method that, for the first time, enables simultaneous control of bunch duration and synchronization with few-fs precision. Timing stabilization is achieved…

Fiducial-Cosmology-dependent systematics for the DESI 2024 Full-Shape Analysis
R. Gsponer, S. Ramirez-Solano, F. Rodr\'iguez-Mart\'inez, M. Vargas-Maga\~na, S. Novell-Masot, N. Findlay, H. Gil-Mar\'in, P. Zarrouk, S. Nadathur, A. Rocher, S. Brieden, A. P\'erez-Fern\'andez, J. Aguilar, S. Ahlen, D. Bianchi, D. Brooks, F. J. Castander, T. Claybaugh, A. Cuceu, A. de la Macorra, A. de Mattia, Arjun Dey, P. Doel, A. Font-Ribera, J. E. Forero-Romero, E. Gazta\~naga, S. Go…

Fiducial-Cosmology-dependent systematics for the DESI 2024 Full-Shape Analysis
We assess the impact of the fiducial cosmology choice on cosmological inference from full-shape (FS) fits of the galaxy power spectrum in the DESI 2024 Data Release 1 (DR1). Using a suite of AbacusSummit DR1 mock catalogues based on the Planck 2018 best-fit cosmology, we quantify potential systematic shifts introduced by analysing the data under five secondary cosmologies - featuring variations in matter density, thawing dark energy, higher effective number of neutrino species, reduced clusteri…

Multipolar magnetic configuration: a trace of post-mergers events in circumstellar disks around FS CMa Stars
A. Moranchel-Basurto, D. Kocakova, M. Cemeljic, R. O. Chametla, F. J. Sanchez-Salcedo, I. Bermejo-Lozano
https://arxiv.org/abs/2508.18974

Multipolar magnetic configuration: a trace of post-mergers events in circumstellar disks around FS CMa Stars
Context: Observations suggest that magnetic fields of disk-bearing stars may have non-dipolar configurations. However, the influence of these configurations on magnetospheric accretion remains poorly understood. Aims: We aim to simulate magnetospheric accretion incorporating non-dipolar and strong magnetic field. Our model is informed by observations of IRAS 17449+2320, a post-merger belonging to the group of FS CMa stars, which indicate a dominant dipolar magnetic field with an additional quad…

Travis Kelce on Chiefs' Super Bowl LIX loss: 'I've thrown that thing in the trash' https://www.nfl.com/news/travis-kelce-chiefs-super-bowl-lix-loss-ive-thrown-that-thing-in-trash

The Curious Case of High-Dimensional Indexing as a File Structure: A Case Study of eCP-FS
Omar Shahbaz Khan, Gylfi {\TH}\'or Gu{\dh}mundsson, Bj\"orn {\TH}\'or J\'onsson
https://arxiv.org/abs/2507.21939

The Curious Case of High-Dimensional Indexing as a File Structure: A Case Study of eCP-FS
Modern analytical pipelines routinely deploy multiple deep learning and retrieval models that rely on approximate nearest-neighbor (ANN) indexes to support efficient similarity-based search. While many state-of-the-art ANN-indexes are memory-based (e.g., HNSW and IVF), using multiple ANN indexes creates a competition for limited GPU/CPU memory resources, which in turn necessitates disk-based index structures (e.g., DiskANN or eCP). In typical index implementations, the main component is a compl…

Femtosecond signatures of optically induced magnons before ultrafast demagnetization
Reza Rouzegar (Department of Physics, Freie Universit\"at Berlin, Berlin, Germany), Oliver Franke (Department of Physics, Freie Universit\"at Berlin, Berlin, Germany), Gal Lemut (Department of Physics, Freie Universit\"at Berlin, Berlin, Germany), Oliver Gueckstock (Department of Physics, Freie Universit\"at Berlin, Berlin, Germany), Junwei Tong (Department of Physics, Freie Univers…

Femtosecond signatures of optically induced magnons before ultrafast demagnetization
Optically induced demagnetization of 3d metallic ferromagnets proceeds as fast as ~100 fs and is a crucial prerequisite for spintronic applications, such as ultrafast magnetization switching and spin transport. On the 100 fs time scale, the magnetization dynamics is widely understood in the context of temperature models considering energy transfers between conduction electrons, magnons and crystal lattice. However, on even faster time scales, the flow of both angular momentum and energy between…

An accurate measurement of the spectral resolution of the JWST Near Infrared Spectrograph
Anowar J. Shajib, Tommaso Treu, Alejandra Melo, Shawn Knabel, Michele Cappellari, Joshua A. Frieman
https://arxiv.org/abs/2507.03746

An accurate measurement of the spectral resolution of the JWST Near Infrared Spectrograph
The spectral resolution ($R \equiv λ/ Δλ$) of spectroscopic data is crucial information for accurate kinematic measurements. In this letter, we present a robust measurement of the spectral resolution for the JWST's Near Infrared Spectrograph (NIRSpec) in all its modes: fixed slit (FS), integral field spectroscopy (IFS), and multi-object spectroscopy (MOS). We modeled H and He lines of the planetary nebula SMP LMC 58 using a Gaussian line spread function (LSF) to estimate the wavelength-depen…

you can now flash an atmega entirely from your browser* https://glasgowembedded.github.io/glasgow-webusb/
* getting files to/from the virtual filesystem left as an exercise for the reader, bearing in mind that `pyodide.FS` is an Emscripten filesystem object

This just makes me sad :bread_displeased:
Gerade auf der persönlichen Webseite eines WebDevs statt einen `mailto:` einen Direkt-GMail-Link vorgefunden.
(https:||mail.google.com/mail/?view=cm&fs=1&to=$XYZ)

Stellantis warns of $2.7 billion loss as tariffs hit hard
https://qz.com/stellantis-losses-tariffs

Combinatorial Approaches for Embedded Feature Selection in Nonlinear SVMs
Federico D'Onofrio, Yuri Faenza, Laura Palagi
https://arxiv.org/abs/2507.23711 https://

Combinatorial Approaches for Embedded Feature Selection in Nonlinear SVMs
Embedded Feature Selection (FS) is a classical approach for interpretable machine learning, aiming to identify the most relevant features of a dataset while simultaneously training the model. We consider an approach based on a hard cardinality constraint for nonlinear SVMs. To the best of our knowledge, hard-constraint approaches have been proposed only for the primal formulation of linear SVMs. In contrast, we embed a hard cardinality constraint directly into the dual of a nonlinear SVM, guara…

Testing the Generalized Second Law in $(2 1)$-Dimensional Cosmology: Holographic Entropy Bounds and Observational Constraints
Praveen Kumar Dhankar, Aritra Sanyal, Safiqul Islam, Farook Rahaman, Behnam Pourhassan
https://arxiv.org/abs/2508.13227

Testing the Generalized Second Law in $(2+1)$-Dimensional Cosmology: Holographic Entropy Bounds and Observational Constraints
We investigate the validity of the Generalized Second Law (GSL) of thermodynamics in a $(2+1)$-dimensional holographic cosmological model with a negative cosmological constant. Adopting a horizon thermodynamics framework, we examine two prominent entropy bounds, the Fischler--Susskind (FS) bound and the Hubble Entropy (HE) bound, in both expanding and contracting universes, including the effects of quantum entropy corrections. Our theoretical analysis shows that the FS bound is intrinsically in…

Femtosecond-Scale MeV-UED Beamline Using a Stand-Alone Multi-Cell RF Photogun
Thomas Geoffrey Lucas, Paolo Craievich, David Alesini, Carl Beard, Hans-H. Braun, Alexander Dietrich, Zheqiao Geng, Rasmus Ischebeck, Eduard Prat, Mike Seidel, Cezary Sydlo, Alexandre Trisorio, Carlo Vicario, Riccardo Zennaro
https://arxiv.org/abs/2508.09357

Femtosecond-Scale MeV-UED Beamline Using a Stand-Alone Multi-Cell RF Photogun
The temporal resolution of MeV ultrafast electron diffraction (UED) is fundamentally constrained by the electron bunch length at the sample, motivating the development of new electron sources capable of producing femtosecond scale bunches. In this work, we propose a multicell RF photogun that has a tailored phase velocity profile to generate 5 to 15 fs rms MeV electron bunches directly from the electron gun, eliminating the need for downstream compression. This approach achieves comparable perf…

Zernike polynomials from the tridiagonalization of the radial harmonic oscillator in displaced Fock states
Hashim A. Yamani, Zouha\"ir Mouayn
https://arxiv.org/abs/2506.22933

Zernike polynomials from the tridiagonalization of the radial harmonic oscillator in displaced Fock states
We revisit the J-matrix method for the one dimensional radial harmonic oscillator (RHO) and construct its tridiagonal matrix representation within an orthonormal basis phi(z)n of L2 (R+);parametrized by a fixed z in the complex unit disc D and n = 0,1,2,.... Remarkably, for fixed n,and varying z in D, the system phi(z)n forms a family of Perelomov-type coherent states associated with the RHO. For each fixed n, the expansion of phi(z)n over the basis (fs) of eigenfunctions of the RHO yields coef…

Features of Surface Structuring of Direct and Indirect Band Gap Semiconductors by Femtosecond Laser
N. I. Berezovska (Taras Shevchenko National University of Kyiv), I. M. Dmitruk (Taras Shevchenko National University of Kyiv), Ye. S. Hrabovskyi (Taras Shevchenko National University of Kyiv), R. S. Kolodka (Taras Shevchenko National University of Kyiv), O. P. Stanovyi (Taras Shevchenko National University of Kyiv), A. M. Dmytruk (Institute of Physics of NAS of Ukraine), I. V. Blonskyi (…

Features of Surface Structuring of Direct and Indirect Band Gap Semiconductors by Femtosecond Laser
The impact of femtosecond (fs) laser radiation on semiconductors with direct (ZnSe, GaAs, CdZnTe) band gap, with the structurally induced direct-to-indirect band gap transition (PbI2, GaSe) and indirect band gap (Si) has been studied. The fs-laser treatment of semiconductors has been performed in the multi-pulse regime in air environment. The influence of fs-laser radiation parameters on surface morphology of the semiconductors has been analysed by scanning electron microscopy (SEM) and 2D Four…

Derived Stratified-Microlocal Framework and Moduli Space Resolution for the Cheeger-Goresky-Macpherson Conjecture
Jiaming Luo
https://arxiv.org/abs/2508.17833 https://

Derived Stratified-Microlocal Framework and Moduli Space Resolution for the Cheeger-Goresky-Macpherson Conjecture
In this paper, We define the stratified metric $\infty$-category $\mathbf{StratMet}_{\infty}$ and the middle perversity moduli stack $\mathscr{M}^{\mathrm{mid}}$. We construct a universal truncation complex $Ω_{X,\mathrm{FS}}^{\bullet,\mathrm{univ}}$ for a projective variety $X\subseteq\mathbb{P}^N$. By introducing the stratified singular characteristic variety $\mathrm{SSH}_{\mathrm{strat}}$, we establish a microlocal correspondence between metric asymptotic behavior and topology, proving the…

Electric Field Induced Superconductivity in Bilayer Octagraphene
Yitong Yao, Jun Li, Jiacheng Ye, Fan Yang, Dao-Xin Yao
https://arxiv.org/abs/2507.02830 ht…

Electric Field Induced Superconductivity in Bilayer Octagraphene
We investigate the energy bands, magnetism, and superconductivity of bilayer octagraphene with A-A stacking under a perpendicular electric field. A tight-binding model is used to analyze the band structure of the system. The doubling of the unit cell results in each band of the single layer splitting into two. We find that applying a perpendicular electric field increases the band splitting. As the electric field strength increases, the nesting of the Fermi Surface(FS) weakens, eventually disru…

Enhancing Few-shot Keyword Spotting Performance through Pre-Trained Self-supervised Speech Models
Alican Gok, Oguzhan Buyuksolak, Osman Erman Okman, Murat Saraclar
https://arxiv.org/abs/2506.17686

Enhancing Few-shot Keyword Spotting Performance through Pre-Trained Self-supervised Speech Models
Keyword Spotting plays a critical role in enabling hands-free interaction for battery-powered edge devices. Few-Shot Keyword Spotting (FS-KWS) addresses the scalability and adaptability challenges of traditional systems by enabling recognition of custom keywords with only a few examples. However, existing FS-KWS systems achieve subpar accuracy at desirable false acceptance rates, particularly in resource-constrained edge environments. To address these issues, we propose a training scheme that l…

DPI-SPR: A Differentiable Physical Inversion for Shadow Profile Reconstruction Framework in Forward Scatter Radar
ShuQi Lei, Gan Yu, Yuan Tian, XiaoWei Shao
https://arxiv.org/abs/2508.11470

DPI-SPR: A Differentiable Physical Inversion for Shadow Profile Reconstruction Framework in Forward Scatter Radar
Forward scatter radar (FSR) has emerged as an effective imaging modality for target detection, utilizing forward scattering (FS) signals to reconstruct two-dimensional shadow profile images of objects. However, real-world FS signals are inevitably corrupted by noise. Due to the ill-posed nature of electromagnetic inversion and its high sensitivity to noise, existing imaging methods often suffer from degraded performance or even complete failure under low signal-to-noise ratio (SNR) conditions. …

🇺🇦 #NowPlaying on BBCRadio3's #ThroughTheNight
Carl Nielsen, Симфонічний оркестр НРКУ & Thomas Dausgaard:
🎵 Symphony no 6, FS. 116 'Sinfonia semplice'
#CarlNielsen #СимфонічнийоркестрНРКУ #ThomasDausgaard

Mechanistic Insights into Nonthermal Ablation of Copper Nanoparticles under Femtosecond Laser Irradiation
Janghan Park, Freshteh Sotoudeh, Yaguo Wang
https://arxiv.org/abs/2507.17100

Mechanistic Insights into Nonthermal Ablation of Copper Nanoparticles under Femtosecond Laser Irradiation
Femtosecond (fs) laser sintering enables ultrafast and spatially localized energy deposition, making it attractive for additive manufacturing of metal nanoparticles. However, undesired ablation during fs irradiation of copper (Cu) nanoparticles often disrupts uniform sintering, and the underlying ablation mechanisms remain poorly understood. In this work, we investigate the fragmentation and coalescence behavior of Cu nanoparticles subjected to fs laser scanning under fluence conditions relevan…

Bin immer wieder erstaunt wie schnell und unkompliziert die italienische #FS Umbuchungen bei Verspätungen und Zugausfällen abwickelt.
Blöd ist nur, dass ich diesen Service bei fast jeder Reise in Anspruch nehmen muss.
#Bahn #Italien

Start-to-end modelling of laser-plasma acceleration, beam transport and dose deposition of very high-energy electrons for radiotherapy
Rajakrishna Kalvala, Anton Golovanov, Arnaud Courvoisier, Tomer Friling, Eyal Kroupp, Lidan Grishko, Victor Malka
https://arxiv.org/abs/2508.20678

Start-to-end modelling of laser-plasma acceleration, beam transport and dose deposition of very high-energy electrons for radiotherapy
Radiotherapy using very high-energy electron (VHEE) beams generated by a laser-plasma accelerator has garnered significant interest due to its dose distribution capabilities and potential to address limitations of traditional photon-based radiotherapy. To explore the feasibility of such approach, the presented study uses the parameters of OONA, the commercial <1.3\,J, <25\,fs pulse duration laser recently installed at the Weizmann Institute of Science. Through particle-in-cell simulations of la…

Impact of material properties on the spectral broadening process in thin solid media
Viktor Pajer, Levente Lehotai, J\'anos Bohus, Bal\'azs Tari, Mikhail Kalashnikov, \'Ad\'am B\"orzs\"onyi, Roland S. Nagymih\'aly
https://arxiv.org/abs/2508.05071

Impact of material properties on the spectral broadening process in thin solid media
The post-compression of high peak power laser pulses can efficiently increase the peak intensity on target without the need to build additional amplification stages and enlarge the compressor optics. However, to our best knowledge, the spectral broadening of such pulses with different nonlinear media has not yet been investigated systematically. Here we performed an experimental campaign with mJ-class 25 fs pulses, where the conditions of high energy post-compression were emulated. Fused silica…

Nitrogen-vacancy centre formation via local femto-second laser annealing of diamond
Davin Yue Ming Peng, Alexander J Healey, Rebecca Griffin, Benjamin Cumming, Hiroshi Abe, Takeshi Ohshima, Alastair Stacey, Brant C Gibson, Brett C Johnson, Philipp Reineck
https://arxiv.org/abs/2507.18027

Nitrogen-vacancy centre formation via local femto-second laser annealing of diamond
Emerging quantum technologies based on the nitrogen-vacancy (NV) centre in diamond require carefully engineered material with controlled defect density, optimised NV formation processes, and minimal crystal strain. The choice of NV generation technique plays a crucial role in determining the quality and performance of these centres. In this work, we investigate NV centre formation in nitrogen-doped diamond using femtosecond (fs) laser processing. We systematically examine the effect of laser pu…

Testing Signatures of Phantom Crossing through Full-Shape Galaxy Clustering Analysis
Emanuelly Silva, Rafael C. Nunes
https://arxiv.org/abs/2507.13989 http…

Testing Signatures of Phantom Crossing through Full-Shape Galaxy Clustering Analysis
Recent observations of baryon acoustic oscillations (BAO) from the Dark Energy Spectroscopic Instrument (DESI) survey, when combined with measurements of the cosmic microwave background (CMB) and Type Ia supernovae (SNIa), provide compelling evidence for a phantom crossing at late times, along with statistically significant deviations from the standard $Λ$CDM model. In this work, we investigate the role of redshift-space galaxy clustering data by employing the pre-reconstruction full-shape (FS…

First demonstration of coherent radiation imaging for bunch-by-bunch longitudinal compression monitoring
Joseph Wolfenden, Ana Guisao-Betancur, Carsten Welsch, Billy Kyle, Thomas Pacey, Erik Mansten, Sara Thorin, Mathias Brandin
https://arxiv.org/abs/2509.04689

First demonstration of coherent radiation imaging for bunch-by-bunch longitudinal compression monitoring
Longitudinal bunch profile monitoring is a crucial diagnostic requirement in most accelerator facilities. This is particularly true in modern free-electron lasers and novel acceleration schemes, where bunch lengths are often <100 fs and standard instrumentation is invasive or lacks the required resolution. This paper proposes a new monitoring method in this challenging parameter space. Initial proof of principle results for relative compression monitoring via broadband imaging of coherent THz r…

Generation of Intense Deep-Ultraviolet Pulses at 200 nm
X. Xie, S. Soultanis, G. Knopp, A. L. Cavalieri, S. L. Johnson
https://arxiv.org/abs/2507.02756 htt…

Generation of Intense Deep-Ultraviolet Pulses at 200 nm
We report the generation of intense deep ultraviolet pulses at 200 nm with a duration of 48 fs and pulse energy of 130 uJ, achieved via cascaded sum frequency generation using 800 nm femtosecond pulses in barium borate crystals. Efficient frequency up-conversion is realized by optimizing phase-matching conditions and implementing dispersion control, while maintaining the ultrashort pulse characteristics. The generated deep ultraviolet pulses are characterized using two-photon absorption frequen…

On-chip amplification-free fCEO detection and broadband SCG in parabolically width-modulated TFLN waveguides
Tianyou Tang, Simin Yu, Ruixin Zhou, Jianing Zhang, Juanjuan Lu, Guanyu Chen, Tao Zhu, Lingfang Wang
https://arxiv.org/abs/2509.00394

On-chip amplification-free fCEO detection and broadband SCG in parabolically width-modulated TFLN waveguides
We demonstrate amplification-free carrier-envelope offset (fCEO) detection in parabolically width-modulated z-cut thin-film lithium niobate (TFLN) waveguide that simultaneously engineers dispersion and enhances nonlinear interactions. With 116 fs pulses at 1560 nm, the device generates more than two octaves broadband SCG spanning 600 to beyond 2400 nm, enabling spectral overlap between dispersive waves and second-harmonic generation near 780 nm for robust f-2f self-referencing. Most notably, we…

Helical Electron Beam Micro-Bunching by High-Order Modes in a Micro-Plasma Waveguide
Xinju Guo, Longqing Yi
https://arxiv.org/abs/2506.15094 https://

Helical Electron Beam Micro-Bunching by High-Order Modes in a Micro-Plasma Waveguide
Electron acceleration by a high-power Laguerre-Gaussian pulse in a micro-plasma waveguide is investigated. When the incident laser travels in the waveguide, electrons on the wall are extracted into the vacuum core and accelerated by the longitudinal field of the waveguide mode. Using 3D particle-in-cell simulations, we demonstrate that high energy (~100 MeV) electron beams with extremely high charge (~10 nC), ultrashort duration (~30 fs) and small divergence (~1 deg) can be produced by a 100-TW…

Clean few-cycle blue soliton self-compressed pulses generation in hollow-core fibers
Ziping Huang, Jiale Peng, Weitao He, Hongyu Chen, Chengbo Sun, Zhihao Wang, Shuangxi Peng, Lixin He, Qingbin Zhang, Peixiang Lu
https://arxiv.org/abs/2508.19777

Clean few-cycle blue soliton self-compressed pulses generation in hollow-core fibers
Blue pulses with few-cycle temporal durations hold significant value in attosecond science and ultrafast spectroscopy. In this work, we combine efficient broadband frequency doubling, multiplate continuum (MPC) post-compression and blue soliton self-compression in hollow-core fibers (HCF), experimentally demonstrating HCF-based 4.4 fs clean blue soliton self-compressed pulse. Our scheme offers three-fold advantages: (1) prevention of excessive dispersion accumulation by gradually suppressing di…

🇺🇦 #NowPlaying on BBCRadio3's #ThroughTheNight
Carl Nielsen, DR SymfoniOrkestret & Michael SchŸnwandt:
🎵 Pan og Syrinx (Pan and Syrinx) Op 49 FS.87
#CarlNielsen #DRSymfoniOrkestret #MichaelSchønwandt

Simulation of silicon ridge waveguide enhanced two-photon absorption from femtosecond pulses
Cael Warner, Ruoheng Zhang
https://arxiv.org/abs/2506.18098 ht…

Simulation of silicon ridge waveguide enhanced two-photon absorption from femtosecond pulses
Field enhancement of two-photon absorption from a 50-fs pulse on a silicon ridge waveguide is simulated for a varying energy downward propagating 800+/-9.42 nm wavelength plane-wave orthonormal to a waveguide in 2D FDTD using ANSYS Lumerical FDTD. Energy absorbed by the waveguide is enhanced due to mode confinement within the standard 500 nm width, 130 nm height silicon ridge waveguide on 90 nm thick silicon and 3 μm silicon dioxide insulator.

Nonlinear reversal of photo-excitation on the attosecond time scale improves ultrafast x-ray diffraction images
Anatoli Ulmer, Phay J. Ho, Bruno Langbehn, Stephan Kuschel, Linos Hecht, Razib Obaid, Simon Dold, Taran Driver, Joseph Duris, Ming-Fu Lin, David Cesar, Paris Franz, Zhaoheng Guo, Philip A. Hart, Andrei Kamalov, Kirk A. Larsen, Xiang Li, Michael Meyer, Kazutaka Nakahara, Robert G. Radloff, River Robles, Lara R\"onnebeck, Nick Sudar, Adam M. Summers, Linda Young, Peter Wal…

Nonlinear reversal of photo-excitation on the attosecond time scale improves ultrafast x-ray diffraction images
The advent of isolated and intense sub-femtosecond X-ray pulses enables tracking of quantummechanical motion of electrons in molecules and solids. The combination of X-ray spectroscopy and diffraction imaging is a powerful approach to visualize non-equilibrium dynamics in systems beyond few atoms. However, extreme x-ray intensities introduce significant electronic damage, limiting material contrast and spatial resolution. Here we show that newly available intense subfemtosecond (sub-fs) x-ray F…

Measurements of Optical Kerr Nonlinearity n2 in Compressed Gases
Yury E. Geints, Victor O. Kompanets, Sergey V. Chekalin
https://arxiv.org/abs/2508.15191 https://

Measurements of Optical Kerr Nonlinearity n2 in Compressed Gases
High-power optical pulses experience self-focusing when propagating in a gaseous medium due to the manifestation of the cubic (Kerr-like) nonlinearity. The magnitude of this effect depends on the Kerr nonlinearity coefficient n2, which in turn may depend on the parameters of laser radiation and the propagation medium. We present experimental data on the coefficient n2 for atomic Ar, molecular N2 and CO2 with a pressure change from 1 to 11 bar and optical pulse duration from 50 to 500 fs of prop…