search_query=cat:astro-ph.*+AND+lastUpdatedDate:[202604162000+TO+202604222000]&start=0&max_results=5000

New astro-ph.* submissions cross listed on stat.*, cs.LG, cs.AI, physics.data-an staritng 202604162000 and ending 202604222000

Feed last updated: 2026-04-22T05:54:02Z

Automated Classification of Plasma Regions at Mars Using Machine Learning

Authors: Yilan Qin, Chuanfei Dong, Hongyang Zhou, Chi Zhang, Kaichun Xu, Jiawei Gao, Simin Shekarpaz, Xinmin Li, Liang Wang
Comments: 14 pages, 4 figures
Primary Category: physics.space-ph
All Categories: physics.space-ph, astro-ph.EP, cs.LG, physics.plasm-ph

The plasma environment around Mars is highly variable because it is strongly influenced by the solar wind. Accurate identification of plasma regions around Mars is important for the community studying solar wind-Mars interactions, region-specific plasma processes, and atmospheric escape. In this study, we develop a machine-learning-based classifier to automatically identify three key plasma regions--solar wind, magnetosheath, and induced magnetosphere--using only ion omnidirectional energy spectra measured by the MAVEN Solar Wind Ion Analyzer (SWIA). Two neural network architectures are evaluated: a multilayer perceptron (MLP) and a convolutional neural network (CNN) that incorporates short temporal sequences. Our results show that the CNN can reliably distinguish the three plasma regions, whereas the MLP struggles to separate the solar wind and magnetosheath. Therefore, the CNN-based approach provides an efficient and accurate framework for large-scale plasma region identification at Mars and can be readily applied to future planetary missions.


Simple approximations of some statistical functions

Authors: Zinovy Malkin
Comments: No comment found
Primary Category: astro-ph.IM
All Categories: astro-ph.IM, physics.data-an, stat.CO

Possibilities are considered to simplify the computation of several statistical functions used to test statistical hypotheses when processing observations: the inverse normal distribution, the Student's t-distribution, and the criterion for rejecting outliers. For these three cases, simple approximation expressions are proposed for the quantiles of these statistical distributions, which are accurate enough for most practical applications.


Gravitational-wave astronomy requires population-informed parameter estimation

Authors: Matthew Mould, Rodrigo Tenorio, Davide Gerosa
Comments: No comment found
Primary Category: gr-qc
All Categories: gr-qc, astro-ph.HE, astro-ph.IM, physics.data-an

Gravitational-wave events are interpreted in terms of Bayesian posteriors for their source properties inferred under unphysical reference priors. Though these parameter estimates are important intermediate data products for downstream analyses, across the catalog they provide generically biased sourced properties and are therefore unsuitable for direct astrophysical interpretation. Hierarchical parameter estimation is the solution, where joint analysis of the entire catalog of observations not only reduces statistical uncertainties but actually informs the correct prior. Population-informed source properties from there derived are naturally suited to astrophysical interpretation and catalog statistics, such as identification of exceptional events from previous and ongoing observing runs. Using the latest LIGO-Virgo-KAGRA data, we thus demonstrate that population inference is not optional to interpret gravitational-wave observations.