Tootfinder

Iterative Methods for Computing the Moore-Penrose Pseudoinverse of Quaternion Matrices, with Applications
Valentin Leplat, Salman Ahmadi-Asl, JunJun Pan, Ning Zheng
https://arxiv.org/abs/2508.16979

Iterative Methods for Computing the Moore-Penrose Pseudoinverse of Quaternion Matrices, with Applications
We develop iterative methods to compute the Moore-Penrose pseudoinverse of quaternion matrices directly in $\mathbb{H}$. We introduce a damped Newton-Schulz (NS) iteration, proving its convergence under spectral scaling $X_0=αA^H$ with $α\in(0,2/\|A\|_2^2)$. We derive higher-order hyperpower NS schemes with optimized factorizations. Beyond NS, we propose a randomized sketch-and-project method (RSP-Q) and a conjugate gradient on normal equations (CGNE-Q). Numerically, spectrally-scal…

Ooooo….
https://www.linuxfoundation.org/press/linux-foundation-announces-the-fair-package-manager-project-for-open-source-content-management-system-stability

Linux Foundation Announces the FAIR Package Manager Project for Open Source Content Management System Stability
Linux Foundation announces FAIR Package Manager project, creating simplicity, security and consistency for the WordPress ecosystem

Lunar Orbital VLBI Experiment: motivation, scientific purposes and status
Xiaoyu Hong, Weiren Wu, Qinghui Liu, Dengyun Yu, Chi Wang, Tao Shuai, Weiye Zhong, Renjie Zhu, Yonghui Xie, Lihua Zhang, Liang Xiong, Yuhua Tang, Yongliao Zou, Haitao Li, Guangli Wang, Jianfeng Xie, Changbin Xue, Hao Geng, Juan Zhang, Xiaojing Wu, Yong Huang, Weimin Zheng, Lei Liu, Fang Wu, Xiuzhong Zhang, Tao An, Xiaolong Yang, Fengxian Tong, Leonid I. Gurvits, Yong Zheng, Minfeng Gu, Xiaofei Ma, Liang Li, Peiji…

Lunar Orbital VLBI Experiment: motivation, scientific purposes and status
The Lunar Orbital VLBI Experiment (LOVEX) is a scientific component of the Chinese Lunar Exploration Project (CLEP) Chang'E-7. The spaceborne component of LOVEX is implemented onboard the relay satellite QueQiao-2, which was launched on 2024 March 20, and later placed into an elliptical selenocentric orbit. The LOVEX-specific payload consists of an X-band cryogenic receiver, a hydrogen maser frequency standard, and VLBI data formatting and acquisition electronics. Several components of the QueQ…

lol this project can go fuck itself
https://www.theregister.com/2025/06/10/xlibre_new_xorg_fork/

Forked-off Xlibre tells Wayland display protocol to DEI in a fire
: Project to modernize the X.org X11 server seems to actively court controversy

Olivia Chow found her spine again and now asking the Executive Committee to support a full RapidTO project on Bathurst and Dufferin, not just the shorten version to Bloor
https://www.toronto.ca/legdocs/mmis/2025/ex/comm/communicationfile-194886.pdf

My son's becoming a true master with #WorldPainter & #WorldMachine and has been creating some stunning and super detailed landscapes (not just alpines ones) for #Minecraft/Ardacraft/…

Nekso (@Nekso@mastodon.gamedev.place)
Attached: 2 images The new map is officially out! Download here: https://www.planetminecraft.com/project/etelande-free-custom-realistic-minecraft-mountain-range-2-5k-x-2-5k-1-21-5/ #minecraft #minecraftmap #terrain

Today's project: adding and programming the Mercury X as my main/only effects unit. Hands-down the most inspiring digital pedal I've ever played with.
#GearSquad #guitar #GuitarEffects

The next #Starship webcast has finally begun: https://www.youtube.com/watch?v=5hgDhgTaV5s. Project Skyfall involves two filming locations, Pompano Beach in Florida, and Raccoon Cay in the Bahamas: https://x.com/interstellargw/status/1926352534559445104

BASS XLVIII: [Ne v] {\lambda}3427 Emission in Powerful Nearby Active Galactic Nuclei
Tomer Reiss, Benny Trakhtenbrot, Claudio Ricci, Franz E. Bauer, Michael J. Koss, Kohei Ichikawa, Darshan Kakkad, Richard Mushotzky, Kyuseok Oh, Alessandro Peca, Rudolf B\"ar, Yaherlyn Diaz, Fiona Harrison, Meredith C. Powell, Eleonora Sani, Daniel Stern, C. Megan Urry

BASS XLVIII: [Ne v] λ3427 Emission in Powerful Nearby Active Galactic Nuclei
We investigate the high-ionization, narrow [Ne v] $λ$3427 emission line in a sample of over 340 ultrahard X-ray (14-195 keV) selected Active Galactic Nuclei (AGN) drawn from the BASS project. The analysis includes measurements in individual and stacked spectra, and considers several key AGN properties such as X-ray luminosity, supermassive black hole (SMBH) mass, Eddington ratios, and line-of-sight column density. The [Ne v] $λ$3427 line is robustly detected in ~43% (146/341) of the AGN in ou…

🇺🇦 #NowPlaying on BBCRadio3's #MusicMap
Walter Werzowa, Beethoven Orchestra Bonn & Dirk Kaftan:
🎵 Beethoven X: The AI Project: III Scherzo. Allegro (Edit)
#WalterWerzowa #BeethovenOrchestraBonn #DirkKaftan
https://open.spotify.com/track/0sGovRNh2CCIryiqiK6Mii

The CUbesat Solar Polarimeter (CUSP): mission overview II
Sergio Fabiani, Ettore Del Monte, Andrea Alimenti, Riccardo Campana, Mauro Centrone, Enrico Costa, Nicolas De Angelis, Giovanni De Cesare, Sergio Di Cosimo, Giuseppe Di Persio, Abhay Kumar, Alessandro Lacerenza, Pasqualino Loffredo, Giovanni Lombardi, Lorenzo Marra, Gabriele Minervini, Fabio Muleri, Paolo Romano, Alda Rubini, Emanuele Scalise, Enrico Silva, Paolo Soffitta, Davide Albanesi, Ilaria Baffo, Daniele Brienza, Valerio …

The CUbesat Solar Polarimeter (CUSP): mission overview II
The CUbesat Solar Polarimeter (CUSP) project is an Earth-orbiting CubeSat mission designed to measure the linear polarization of solar flares in the hard X-ray band using a Compton scattering polarimeter. CUSP will enable the study of magnetic reconnection and particle acceleration within the Sun's flaring magnetic structures. This project is being developed within the framework of the Italian Space Agency's Alcor Program, which aims to foster new CubeSat missions. CUSP entered its Phase B in D…

Modelling the selection of galaxy groups with end to end simulations
R. Seppi, D. Eckert, A. Finoguenov, S . Shreeram, E. Tempel, G. Gozaliasl, M. Lorenz, J. Wilms, G. A. Mamon, F. Gastaldello, L. Lovisari, E. O'Sullivan, K. Kolokythas, M. A. Bourne, M. Sun, A. Pillepich
https://arxiv.org/abs/2506.04757

Modelling the selection of galaxy groups with end to end simulations
Feedback from supernovae and AGN shapes galaxy formation and evolution, yet its impact remains unclear. Galaxy groups offer a crucial probe, as their binding energy is comparable to that available from their central AGN. The XMM-Newton Group AGN Project (X-GAP) is a sample of 49 groups selected in X-ray (ROSAT) and optical (SDSS) bands, providing a benchmark for hydrodynamical simulations. In sight of such a comparison, understanding selection effects is essential. We aim to model the selection…

The Northern Cross Fast Radio Burst project: V. Search for transient radio emission from Galactic magnetars
A. Geminardi, P. Esposito, G. Bernardi, M. Pilia, D. Pelliciari, G. Naldi, D. Dallacasa, R. Turolla, L. Stella, F. Perini, F. Verrecchia, C. Casentini, M. Trudu, R. Lulli, A. Maccaferri, A. Magro, A. Mattana, G. Bianchi, G. Pupillo, C. Bortolotti, M. Tavani, M. Roma, M. Schiaffino, G. Setti

The Northern Cross Fast Radio Burst project: V. Search for transient radio emission from Galactic magnetars
Context. The radio emission from magnetars is poorly understood and poorly characterized observationally, in particular for what concerns single pulses and sporadic events. The interest in it was boosted by the detection in 2020 of an extremely bright ms radio signal from the Galactic magnetar designated Soft Gamma Repeater (SGR) SGR J1935+2154, which occurred almost simultaneously with a typical magnetar short burst of X-rays. As of now, this event remains the Galactic radio pulse that is the …

Sub-keV dark matter can strongly ionize molecular clouds
Pedro De la Torre Luque, Pierluca Carenza, Thong T. Q. Nguyen
https://arxiv.org/abs/2507.01962 htt…

Sub-keV dark matter can strongly ionize molecular clouds
We show that the ionization of dense molecular clouds can be used to set strong constraints on dark matter models producing UV/X-ray photons in their annihilation or decay. We place robust and competitive constraints on various dark matter models, such as axion-like particles, scalars and sterile neutrinos, for masses between $\sim30$~eV and $10$~keV, and project forecasts to illustrate the potential of this target. We discuss how these constraints can be significantly improved by considering a…

The multi-physics analysis, design and testing of CUSP, a CubeSat mission for space weather and solar flares x-ray polarimetry
Giovanni Lombardi, Sergio Fabiani, Ettore Del Monte, Andrea Alimenti, Riccardo Campana, Mauro Centrone, Enrico Costa, Nicolas De Angelis, Giovanni De Cesare, Sergio Di Cosimo, Giuseppe Di Persio, Abhay Kumar, Alessandro Lacerenza, Pasqualino Loffredo, Gabriele Minervini, Fabio Muleri, Paolo Romano, Alda Rubini, Emanuele Scalise, Enrico Silva, Paolo Soffitta, Da…

The multi-physics analysis, design and testing of CUSP, a CubeSat mission for space weather and solar flares x-ray polarimetry
The space-based CUbesat Solar Polarimeter (CUSP) mission aims to measure the linear polarization of solar flares in the hard X-ray band by means of a Compton scattering polarimeter. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed at developing new CubeSat missions. As part of CUSP's Phase B study, which began in December 2024 and will last one year, we present the current development status of the design solutions adopted for the mission's most critical…

The Lockman-SpReSO project. Spectroscopic analysis of Type 1 AGN
Castalia Alenka Negrete, Hector J. Ibarra-Medel, Erika Benitez, Irene Cruz-Gonzalez, Yair Krongold, J. Jesus Gonzalez, Jordi Cepa, Carmen Padilla-Torres, Miguel Cervino, Mirjana Povic, Martin Herrera-Endoqui, Nancy Jenaro-Ballesteros, Takamitsu Miyaji, Mauricio Elias-Chavez, Miguel Sanchez-Portal, Bernabe Cedres, Jacub Nadolny, Mauro Gonzalez-Otero, Bereket Assefa, Hector Hernandez-Toledo, J. Antonio de Diego, J. Ignacio …

The Lockman-SpReSO project. Spectroscopic analysis of Type 1 AGN
We present the first optical-UV spectral systematic analysis of 30 Type 1 AGN selected in the FIR and X-ray in the Lockman-SpReSO Survey. The sample of faint objects (m_B = 19.6-21.8) covers a large redshift range of 0.33 > z > 4.97 with high S/N (~21 on average). A detailed spectral analysis based on the Quasar Main Sequence phenomenology prescription was applied to deblend the principal optical-UV emitting regions. Our sample spans a bolometric luminosity range of 44.85 < log Lbol < 47.87, ab…

CUbesat Solar Polarimeter (CUSP) Sensitivity Estimation and Performance Optimization using Geant4
Abhay Kumar (INAF-IAPS, Rome, Italy), Giovanni Lombardi (INAF-IAPS, Rome, Italy), Giovanni De Cesare (INAF-OAS Bologna, Bologna, Italy), Nicolas De Angelis (INAF-IAPS, Rome, Italy), Sergio Fabiani (INAF-IAPS, Rome, Italy), Ettore Del Monte (INAF-IAPS, Rome, Italy), Andrea Alimenti (INAF-IAPS, Rome, Italy), Riccardo Campana (INAF-OAS Bologna, Bologna, Italy), Enrico Costa (INAF-IAPS, Rome, …

CUbesat Solar Polarimeter (CUSP) Sensitivity Estimation and Performance Optimization using Geant4
The CUbesat Solar Polarimeter (CUSP) aims to measure the linear polarization of solar flares in the 25-100 keV X-ray band using a Compton scattering polarimeter. CUSP will allow us to study the magnetic reconnection and particle acceleration in the flaring magnetic structures of our star by providing high-sensitivity polarization measurements. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop innovative CubeSat technologies and missions. As par…

Study of the HV power supply modules for the CUbesat Solar Polarimeter (CUSP)
Alessandro Lacerenza, Alda Rubini, Andrea Alimenti, Sergio Fabiani, Ettore Del Monte, Riccardo Campana, Mauro Centrone, Enrico Costa, Nicolas De Angelis, Giovanni De Cesare, Sergio Di Cosimo, Giuseppe Di Persio, Abhay Kumar, Pasqualino Loffredo, Giovanni Lombardi, Gabriele Minervini, Fabio Muleri, Paolo Romano, Emanuele Scalise, Enrico Silva, Paolo Soffitta, Davide Albanesi, Ilaria Baffo, Daniele Brienza, Val…

Study of the HV power supply modules for the CUbesat Solar Polarimeter (CUSP)
The CUbesat Solar Polarimeter (CUSP) project is a CubeSat mission orbiting the Earth aimed to measure the linear polarization of solar flares in the hard X-ray band by means of a Compton scattering polarimeter. CUSP will allow to study the magnetic reconnection and particle acceleration in the flaring magnetic structures of our star. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop new CubeSat missions. CUSP undergoing the Phase B started in D…

Prototype Development and Calibration of the CUbesat Solar Polarimeter (CUSP)
Nicolas De Angelis, Abhay Kumar, Sergio Fabiani, Ettore Del Monte, Enrico Costa, Giovanni Lombardi, Paolo Soffitta, Andrea Alimenti, Riccardo Campana, Mauro Centrone, Giovanni De Cesare, Sergio Di Cosimo, Giuseppe Di Persio, Alessandro Lacerenza, Pasqualino Loffredo, Gabriele Minervini, Fabio Muleri, Paolo Romano, Alda Rubini, Emanuele Scalise, Enrico Silva, Davide Albanesi, Ilaria Baffo, Daniele Brienza, Val…

Prototype Development and Calibration of the CUbesat Solar Polarimeter (CUSP)
The space-based CUbesat Solar Polarimeter (CUSP) mission aims to measure the linear polarization of solar flares in the hard X-ray band by means of a Compton scattering polarimeter. CUSP will allow to study the magnetic reconnection and particle acceleration in the flaring magnetic structures of our star with its unprecedented sensitivity to solar flare polarization. CUSP is a project in the framework of the Alcor Program of the Italian Space Agency aimed to develop new CubeSat missions. It has…