Tootfinder

Bohmian Chaos and Entanglement in a Two-Qubit System
Athanasios C. Tzemos, George Contopoulos, Foivos Zanias
https://arxiv.org/abs/2509.10229 https://arxiv…

Bohmian Chaos and Entanglement in a Two-Qubit System
We study in detail the critical points of Bohmian flow, both in the inertial frame of reference (Y-points) and in the frames centered at the moving nodal points of the guiding wavefunction (X-points), and analyze their role in the onset of chaos in a system of two entangled qubits. We find the distances between these critical points and a moving Bohmian particle at varying levels of entanglement, with particular emphasis on the times at which chaos arises. Then, we find why some trajectories ar…

A 28nm Multiply-Accumulate ASIC Architecture for On-Chip Data Compression in MHz Frame Rate X-ray and Electron Pixel Detectors
Rami Rasheedi, Nicholas Contini, Mohamed Adel Gharib, Sebastian Strempfer, Senthil Gnanasekaran, Salma Abdelzaher, Tejas Guruswamy, Kazutomo Yoshii, Mike Hammer, Henry Shi, Yu-Sheng Chen, Lorenzo Rota, Dionisio Doering, Angelo Dragone, Tao Zhou, Antonino Miceli

A 28nm Multiply-Accumulate ASIC Architecture for On-Chip Data Compression in MHz Frame Rate X-ray and Electron Pixel Detectors
Modern X-ray detector systems urgently require compact, efficient, and fast data compression schemes to handle the transmission of big data from pixel arrays, enabling frame rates in the MHz regime. In this work, a data compression ASIC that implements a streaming fixed-length lossy compression scheme is introduced and analyzed, proving the feasibility and benefits of on-chip compression. The compression scheme utilizes a vector matrix product logic, which performs a number of floating-point mu…

At #burningman this year, I brought a small 1200 lumen projector that I could mount on my bike. Would it be feasible to do some quick on the fly projection mapping? It seems that yes, for somewhat small (about 6m x 3m max for reasonable brightness) and not very bright pieces, it works.
I may experiment with this more in the future.

Frame properties induced by iteration of a multiplication operator on Hardy spaces
Jahangir Cheshmavar
https://arxiv.org/abs/2509.04879 https://arxiv.org/p…

Frame properties induced by iteration of a multiplication operator on Hardy spaces
Motivated by the study of frame properties arising from iterates of linear operators, it was previously established that the multiplication operator $T_ϕx(t) = ϕ(t)x(t)$ cannot generate a frame in $L^2(a,b)$ (Results Math, 2019). In this note, we examine the behavior of such operators on the Hardy space $H^2(D)$, the Hilbert space of holomorphic functions on the open unit disk $D$ with square integrable boundary values. We show that, in contrast to the $L^2$-setting, the iterates of $T_ϕ$, f…

X-ray polarization of reflected thermal emission
J. Podgorn\'y, M. Dov\v{c}iak, R. Goosmann, F. Marin, L. Marra, G. Matt, A. R\'o\.za\'nska, R. Taverna
https://arxiv.org/abs/2507.23687

X-ray polarization of reflected thermal emission
X-ray thermal emission is inherent in neutron-star and black-hole X-ray binary systems. Within these systems, it may reflect from optically thick matter, which will create characteristic observable X-ray spectro-polarimetric features. We compute rest-frame reflection spectra and the corresponding energy-dependent linear polarization degree and angle for (un)polarized single-temperature black-body spectra impinging on a partially ionized constant-density optically thick slab. We use a combinatio…

Influence of the nuclear magnetic field on electron-positron pair production in low-energy heavy-nuclei collisions
N. K. Dulaev, D. A. Telnov, V. M. Shabaev, Y. S. Kozhedub, X. Ma, I. A. Maltsev, R. V. Popov, I. I. Tupitsyn
https://arxiv.org/abs/2509.07904

Influence of the nuclear magnetic field on electron-positron pair production in low-energy heavy-nuclei collisions
Total and energy-angle differential probabilities of positrons created in slow collisions of two identical nuclei are calculated within relativistic two-center approach. The time-dependent Dirac equation is solved in the rotating frame using the generalized pseudospectral method in modified prolate spheroidal coordinates. The magnetic interaction induced by the motion of the nuclei is included in the Hamiltonian. The rotational coupling term is also taken into account. Angle-integrated and angl…

Regularization of Inverse Problems by Filtered Diagonal Frame Decomposition under general source
Dang Duc Trong, Nguyen Dang Minh, Luu Xuan Thang, Luu Dang Khoa
https://arxiv.org/abs/2507.23651

Regularization of Inverse Problems by Filtered Diagonal Frame Decomposition under general source
Let $X$ and $Y$ be Hilbert spaces, and $\mathbf{K}: \text{dom} \mathbf{K} \subset X \to Y$ a bounded linear operator. This paper addresses the inverse problem $\mathbf{K}x = y$, where exact data $y$ is replaced by noisy data $y^δ$ satisfying $\|y^δ- y\|_Y \leq δ$. Due to the ill-posedness of such problems, we employ regularization methods to stabilize solutions. While singular value decomposition (SVD) provides a classical approach, its computation can be costly and impractical for…

JWST-discovered AGN: evidence for heavy obscuration in the type-2 sample from the first stacked X-ray detection
Andrea Comastri, Giorgio Lanzuisi, Fabio Vito, Stefano Marchesi, Marcella Brusa, Roberto Gilli, Ignas Juodzbalis, Roberto Maiolino, Giovanni Mazzolari, Guido Risaliti, Jan Scholtz, Cristian Vignali
https://arxiv.org/abs/2510.0011…

JWST-discovered AGN: evidence for heavy obscuration in the type-2 sample from the first stacked X-ray detection
One of the most puzzling properties of the high-redshift AGN population recently discovered by JWST, including both broad-line and narrow-line sources, is their X-ray weakness. With very few exceptions, and regardless of the optical classification, they are undetected at the limits of the deepest Chandra fields, even when stacking signals from tens of sources in standard observed-frame energy intervals (soft, hard, and full bands). It has been proposed that their elusive nature in the X-ray ban…

Dichography: Two-frame Ultrafast Imaging from a Single Diffraction Pattern
Linos Hecht, Andre Al Haddad, Bj\"orn Bastian, Thomas M. Baumann, Johan Bielecki, Christoph Bostedt, Subhendu De, Alberto De Fanis, Simon Dold, Thomas Fennel, Fanny Goy, Christina Graf, Robert Hartmann, Georg Jakobs, Maximilian Joschko, Gregor Knopp, Katharina Kolatzki, Sivarama Krishnan, Bj\"orn Kruse, Asbj{\o}rn {\O}. L{\ae}gdsmand, Bruno Langbehn, Suddhasattwa Mandal, Tommaso Mazza, Michael Meyer, C…

Dichography: Two-frame Ultrafast Imaging from a Single Diffraction Pattern
X-ray free-electron lasers can nowadays deliver pairs of ultrabright, ultrashort light pulses with controllable delays at different photon energies. When combined with diffraction experiments, the interaction of these pulses with a sample at different times can produce two snapshots of an evolving system, enabling spatial and temporal resolution of ultrafast dynamics in nanomatter at and beyond the terahertz time scale. However, light detectors are orders of magnitude slower. The diffraction si…

Using Faded Changing-Look Quasars to Unveil the Spectral Energy Distribution Evolution of Low-Luminosity Active Galactic Nuclei
Olivier Gilbert, John J. Ruan, Laura Duffy, Michael Eracleous, Scott F. Anderson, Paul J. Green, Daryl Haggard, Richard M. Plotkin, Jessie C. Runnoe, Malgorzata Sobolewska
https://arxiv.org/abs/2508.01933

Using Faded Changing-Look Quasars to Unveil the Spectral Energy Distribution Evolution of Low-Luminosity Active Galactic Nuclei
The structure of accretion flows in low-luminosity active galactic nuclei (AGN) at low Eddington ratios (~10^-2 to 10^-3) are poorly-understood, and can be probed using the spectral energy distributions (SEDs) of faded changing-look (CL) quasars. Previous results using single-epoch X-ray and rest-frame UV observations of samples of faded CL quasars suggest that their SED properties at low Eddington ratios display similarities to X-ray binaries fading from outburst. However, more robust tests de…

What you see is what you get: empirically measured bolometric luminosities of Little Red Dots
Jenny E. Greene, David J. Setton, Lukas J. Furtak, Rohan P. Naidu, Marta Volonteri, Pratika Dayal, Ivo Labbe, Pieter van Dokkum, Rachel Bezanson, Gabriel Brammer, Sam E. Cutler, Karl Glazebrook, Anna de Graaff, Michaela Hirschmann, Raphael E. Hviding, Vasily Kokorev, Joel Leja, Hanpu Liu, Yilun Ma, Jorryt Matthee, Themiya Nanayakkara, Pascal A. Oesch, Richard Pan, Sedona H. Price, Justin S. Sp…

What you see is what you get: empirically measured bolometric luminosities of Little Red Dots
New populations of red active galactic nuclei (known as ``Little Red Dots'') discovered by JWST exhibit remarkable spectral energy distributions. Leveraging X-ray through far-infrared observations of two of the most luminous known Little Red Dots, we directly their bolometric luminosities. We find evidence that more than half of the bolometric luminosity likely emerges in the rest-frame optical, with $L_{\rm bol}/L_{5100} = 5$, roughly half the value for ``standard'' Active Galactic Nuclei. Mea…

Gemini Near Infrared Spectrograph$-$Distant Quasar Survey: the Chandra View
Andrea Marlar (U. North Texas), Ohad Shemmer (U. North Texas), Michael S. Brotherton (U. Wyoming), Gordon T. Richards (Drexel U), Cooper Dix (U. Texas at Austin), Brandon M. Matthews (U. North Texas), W. N. Brandt (Penn State U), R. M. Plotkin (U. Nevada at Reno)
https://

Gemini Near Infrared Spectrograph$-$Distant Quasar Survey: the Chandra View
We present Chandra observations of 63 sources from the Gemini Near Infrared Spectrograph$-$Distant Quasar Survey (GNIRS-DQS) of which 54 were targeted by snapshot observations in Cycle 24. A total of 55 sources are clearly detected in at least one X-ray band, and we set stringent upper limits on the X-ray fluxes of the remaining eight sources. In combination with rest-frame ultraviolet-optical spectroscopic data for these sources, we assess whether X-rays can provide a robust accretion-rate ind…

Multi-color XFEL pulses with variable color separation and time delay for multi-frame diffraction imaging
Xiaodan Liu, Hanxiang Yang, Bingyang Yan, Yue Wang, Nanshun Huang, Liqi Han, Jie Cai, Han Wen, Jinqing Yu, Haixiao Deng, Xueqing Yan
https://arxiv.org/abs/2509.14906

Multi-color XFEL pulses with variable color separation and time delay for multi-frame diffraction imaging
X-ray free-electron lasers (XFELs) of high brightness have opened new opportunities for exploring ultrafast dynamical processes in matter, enabling imaging and movies of single molecules and particles at atomic resolution. In this paper, we present a straightforward method for multi-frame diffraction imaging, using the same electron beam to generate four-color XFEL pulses with adjustable wavelength separation and time delay. The optical klystron scheme is introduced to enhance FEL intensity and…

JADES: Carbon-enhanced, Nitrogen-normal compact galaxy at z=11.2
J. Scholtz, M. S. Silcock, E. Curtis-Lake, R. Maiolino, S. Carniani, F. D'Eugenio, X. Ji, P. Jakobsen, K. Hainline, S. Arribas, W. M. Baker, R. Bhatawdekar, A. J. Bunker, S. Charlot, J. Chevallard, M. Curti, Daniel J. Eisenstein, Y. Isobe, G. C. Jones, E. Parlanti, P. G. P\'erez-Gonz\'alez, P. Rinaldi, B. Robertson, S. Tacchella, H. \"Ubler, C. C. Williams, C. Willott, J. Witstok

JADES: Carbon-enhanced, Nitrogen-normal compact galaxy at z=11.2
Over the past few years \textit{JWST} has been a major workhorse in detecting and constraining the metal enrichment of the first galaxies in the early Universe and finding the source of the ionisation of their interstellar medium. In this work, we present new deep JWST/NIRSpec spectroscopy of GS-z11-1, a galaxy at z = 11.28, in which we report the detection of multiple rest-frame UV and optical emission lines: CIII]$λλ$1907,09, CIV]$λλ$1548,51, [OII]$λλ$3726,29, [NeIII]$λ$3869, H$γ$ and…