Tootfinder

On Alperin's conjecture and functorial equivalence of blocks
Robert Boltje, Serge Bouc, Deniz Y{\i}lmaz
https://arxiv.org/abs/2507.20314 https://arxiv.…

On Alperin's conjecture and functorial equivalence of blocks
Let $k$ be an algebraically closed field of positive characteristic $p$ and let $\mathbb{F}$ be an algebraically closed field of characteristic 0. We consider Alperin's weight conjecture (over $k$) from the point of view of (stable) functorial equivalence of blocks over $\mathbb{F}$. We formulate a functorial version of Alperin's blockwise weight conjecture, and show that it is equivalent to the original one. We also show that this conjecture holds stably, i.e., in the category of stable diagon…

A first-order condition for discrete-time distribution steering
Alberto Dom\'inguez Corella, David Gonz\'alez-S\'anchez
https://arxiv.org/abs/2508.21026 https://

A first-order condition for discrete-time distribution steering
We study a class of distribution-steering problems from a variational point of view. Under some differentiability assumptions, we derive necessary conditions for optimal Markov policies in the spirit of the Lagrange multiplier approach. We also provide a heuristic gradient-based method derived from the variational principle.

A multi-frequency, multi-epoch radio continuum study of the Quintuplet cluster with the Very Large Array
M. Cano-Gonz\'alez, R. Sch\"odel, A. Alberdi, J. Mold\'on, M. P\'erez-Torres, F. Najarro, A. T. Gallego-Calvente
https://arxiv.org/abs/2507.21617

A multi-frequency, multi-epoch radio continuum study of the Quintuplet cluster with the Very Large Array
The Quintuplet cluster, located in the Galactic centre, is one of the few young massive clusters in the Milky Way. It allows us to study dozens of massive, post main sequence stars individually, providing unique insights into the properties of the most massive stars. Our goal is to study the radio continuum emission of the most massive stars in the cluster. We carried out a total of nine observations (three in the C- and six in the X-band) of the Quintuplet cluster with the Karl G. Jansky Ver…

Classification with Reject Option: Distribution-free Error Guarantees via Conformal Prediction
Johan Hallberg Szabadv\'ary, Tuwe L\"ofstr\"om, Ulf Johansson, Cecilia S\"onstr\"od, Ernst Ahlberg, Lars Carlsson
https://arxiv.org/abs/2506.21802

Classification with Reject Option: Distribution-free Error Guarantees via Conformal Prediction
Machine learning (ML) models always make a prediction, even when they are likely to be wrong. This causes problems in practical applications, as we do not know if we should trust a prediction. ML with reject option addresses this issue by abstaining from making a prediction if it is likely to be incorrect. In this work, we formalise the approach to ML with reject option in binary classification, deriving theoretical guarantees on the resulting error rate. This is achieved through conformal pred…

Online design of experiments by active learning for nonlinear system identification
Kui Xie, Alberto Bemporad
https://arxiv.org/abs/2506.21754 https://

Online design of experiments by active learning for nonlinear system identification
We investigate the use of active-learning (AL) strategies to generate the input excitation signal at runtime for system identification of linear and nonlinear autoregressive and state-space models. We adapt various existing AL approaches for static model regression to the dynamic context, coupling them with a Kalman filter to update the model parameters recursively, and also cope with the presence of input and output constraints. We show the increased sample efficiency of the proposed approache…

The constraining power of X-ray polarimetry: detailed structure of the intrabinary bow shock in Cygnus X-3
Varpu Ahlberg, Anastasiia Bocharova, Alexandra Veledina
https://arxiv.org/abs/2507.21708

The constraining power of X-ray polarimetry: detailed structure of the intrabinary bow shock in Cygnus X-3
Cygnus X-3 is the only known Galactic high-mass X-ray binary with a Wolf-Rayet companion. Recent X-ray polarimetry results with the Imaging X-ray Polarimetry Explorer have revealed it as a concealed ultraluminous X-ray source. It is also the first source where pronounced orbital variability of X-ray polarization has been detected -- notably with only one polarization maximum per orbit. Polarization caused by scattering of the source X-rays can only be orbitally variable if the scattering angles…

"In old times, and also in our time among the Indian tribes, psychedelic substances were considered sacred and they were used with the right attitude and in a ritual and spiritual context. And what a difference if we compare it with the careless and irresponsible use of LSD in the streets and in the discotheques of New York City and everywhere in the West. It is a tragic misunderstanding of the nature and the meaning of these kinds of substances."
— Albert Hofmann

SBND-PRISM: Sampling Off-Axis Neutrino Fluxes with the Short-Baseline Near Detector
P. Abratenko, R. Acciarri, C. Adams, L. Aliaga-Soplin, O. Alterkait, R. Alvarez-Garrote, D. Andrade Aldana, C. Andreopoulos, A. Antonakis, L. Arellano, J. Asaadi, S. Balasubramanian, A. Barnard, V. Basque, J. Bateman, A. Beever, E. Belchior, M. Betancourt, A. Bhat, M. Bishai, A. Blake, B. Bogart, D. Brailsford, A. Brandt, S. Brickner, M. B. Brunetti, L. Camilleri, D. Caratelli, D. Carber, B. Carlson, M.…

SBND-PRISM: Sampling Off-Axis Neutrino Fluxes with the Short-Baseline Near Detector
The Short-Baseline Near Detector (SBND), the near detector in the Short-Baseline Neutrino Program at Fermi National Accelerator Laboratory, is located just 110 m from the Booster Neutrino Beam target. Thanks to this close proximity, relative to its 4 m $\times$ 4 m front face, neutrinos enter SBND over a range of angles from $0^{\circ}$ to approximately $1.6^{\circ}$, enabling the detector to sample variations in the neutrino flux as a function of angle-a technique known as PRISM, referred to h…

Advanced System Engineering Approaches to Emerging Challenges in Planetary and Deep-Space Exploration
J. de Curt\`o, Cristina LiCalzi, Julien Tubiana Warin, Jack Gehlert, Brian Langbein, Alexandre Gamboa, Chris Sixbey, William Maguire, Santiago Fern\'andez, \'Alvaro Maestroarena, Alex Brenchley, Logan Maroclo, Philemon Mercado, Joshua DeJohn, Cesar Velez, Ethan Dahmus, Taylor Steinys, David Fritz, I. de Zarz\`a

Advanced System Engineering Approaches to Emerging Challenges in Planetary and Deep-Space Exploration
This paper presents innovative solutions to critical challenges in planetary and deep-space exploration electronics. We synthesize findings across diverse mission profiles, highlighting advances in: (1) MARTIAN positioning systems with dual-frequency transmission to achieve $\pm$1m horizontal accuracy; (2) artificial reef platforms for Titan's hydrocarbon seas utilizing specialized sensor arrays and multi-stage communication chains; (3) precision orbital rendezvous techniques demonstrating nove…

NuSTAR and XMM-Newton Observations of PSR J1930 1852 and Its Pulsar Wind Nebula
J. A. J. Alford, G. -B. Zhang, J. D. Gelfand
https://arxiv.org/abs/2506.22409

NuSTAR and XMM-Newton Observations of PSR J1930+1852 and Its Pulsar Wind Nebula
Synchrotron X-ray emission from a pulsar wind nebula (PWN) is a sensitive probe of its magnetic field and high-energy particle population. Here we analyze contemporaneous NuSTAR and XMM-Newton observations of the PWN G54.1+0.3, powered by pulsar PSR J1930+1852. We also present a preliminary timing analysis of the central pulsar PSR J1930+1852 and analyze its X-ray pulse profiles in different energy bands. We detect X-ray emission from the combined pulsar and PWN system up to $\approx70$ keV, wh…