search_query=cat:astro-ph.*+AND+lastUpdatedDate:[202606102000+TO+202606162000]&start=0&max_results=5000

New astro-ph.* submissions cross listed on physics.data-an, stat.*, cs.LG, cs.AI staritng 202606102000 and ending 202606162000

Feed last updated: 2026-06-16T09:14:17Z

Neural Bayesian Anomaly Mitigation: A Robust Loss that Doubles as an Unsupervised Contamination Classifier

Authors: S. A. K. Leeney, W. J. Handley, H. T. J. Bevins, E. de Lera Acedo
Comments: 13 pages, 4 figures
Primary Category: cs.LG
All Categories: cs.LG, astro-ph.CO, stat.ML

Engineered robust losses such as Huber, Student-$t$, and generalised cross-entropy make supervised models tolerant of contamination but cannot answer which observations are corrupted. We introduce Neural Bayesian Anomaly Mitigation (NBAM), a general-purpose drop-in loss derived from a Bayesian latent-switch mixture model: the marginal likelihood defines a robust supervised loss, and the associated posterior defines an unsupervised contamination classifier. Like Huber or Student-$t$, NBAM can replace the standard training loss in any supervised pipeline; unlike them, it additionally learns a structured contamination model and returns a calibrated per-sample contamination posterior. A learned input-dependent prior $π_φ(x)$ captures the spatial locality of contamination, so that samples near known corruptions are more likely to be flagged, while an Occam penalty emerges automatically and regularises against over-flagging. On CIFAR-10 with asymmetric label contamination, NBAM recovers the structure of the corruption process without supervision: the contamination posterior separates clean from corrupted samples, and the learned anomaly head identifies the direction of every label-flip pair. Alongside these capabilities, NBAM outperforms the four robust-loss baselines considered here at contamination rates 0.2-0.6.


LLM Judges Have Dark Current: A Psychometric Datasheet for LLM-as-a-Judge Evaluation

Authors: Hiroyasu Usami, Keisuke Hara, Ayato Tsuboi, Naohiko Matsuda
Comments: 22 pages, 4 figures
Primary Category: cs.CL
All Categories: cs.CL, astro-ph.IM, cs.AI, cs.LG

LLM-as-a-judge systems are now routinely used for open-ended model evaluation, where human preference annotation is costly, slow, and difficult to reproduce. Yet these judges are often reported as scalar accuracy, win-rate, or agreement devices. We argue that a judge should instead be reported as a measurement instrument. We introduce a Judge Datasheet protocol that measures dark current under true-vacuum inputs, stable cross-sensitivity to same-quality surface variation, positional false preference, target sensitivity on a controlled quality ladder, and the criterion or operating point induced by tie instructions. The direction-stability decomposition reveals that apparent Delta0 preference can be stable surface response or disguised position bias. In a three-judge open-weight case study, Llama-3.1-8B shows high dark current and presentation-conflicted Delta0 behavior, Qwen2.5-14B is vacuum-clean and target-sensitive but mixes stable and positional over-discrimination, and Qwen2.5-32B is vacuum-clean with low stable cross-sensitivity and low positional false preference. A strict tie criterion eliminates Qwen32B Delta0 false preference but absorbs marginal Delta1 target signals into ties while preserving Delta5 sensitivity. The results show that prompting moves the criterion, not the resolution. We do not claim that the downstream mechanism hypothesis that motivated this work is confirmed; the contribution is a metrological protocol for measuring the measuring device before downstream claims are made.


Classification of Astronomical Spectra Using PCA-Compressed Flux and Inverse-Variance Features

Authors: Bruno Santos Meneses Barreto, Marcio Eisencraft
Comments: This manuscript has been submitted to the Simpósio Brasileiro de Telecomunicações e Processamento de Sinais (SBrT) and is currently under peer review
Primary Category: astro-ph.IM
All Categories: astro-ph.IM, cs.LG

This paper evaluates a signal-processing and supervised-learning pipeline for classifying SDSS DR17 astronomical spectra into stars, galaxies, and quasars. Each spectrum is represented by its measured flux and inverse-variance information, combining spectral shape with a wavelength-dependent reliability profile. After resampling onto a common logarithmic wavelength grid, the flux and inverse-variance vectors are standardized and separately compressed using principal component analysis. The resulting components are concatenated and used to train several classifiers. The best performance was obtained with the LightGBM gradient-boosting classifier, reaching $94.6\%$ accuracy and $92.1\%$ balanced accuracy on the test set.


Binary Black Hole Parameter Estimation with Hybrid CNN-Transformer Neural Networks

Authors: Panagiotis N. Sakellariou, Spiros V. Georgakopoulos, Sotiris Tasoulis, Vassilis P. Plagianakos
Comments: Accepted manuscript. 12 pages, 10 figures
Primary Category: gr-qc
All Categories: gr-qc, astro-ph.IM, cs.LG

The detection of gravitational waves has revolutionized our ability to explore fundamental aspects of the Universe. Traditionally, modeled gravitational-wave signals have been identified using template-based matched filtering, followed by coincidence analysis across multiple detectors in the signal-to-noise ratio time series. Recent advances in Machine Learning and Deep Learning have sparked growing interest in their application to both signal detection and parameter estimation. In this study, a hybrid Deep Learning strategy is proposed that leverages the effectiveness of Transformer encoders alongside well-established Convolutional Neural Network architectures in an attempt to estimate the intrinsic and extrinsic parameters of non-precessing binary black hole systems. The primary focus of this work is point estimation, producing single best-fit values for each parameter rather than full posterior distributions. This method is evaluated on both simulated signals embedded in Gaussian noise and real gravitational-wave events, and it demonstrates strong predictive performance and robustness across key astrophysical parameters.


Multi-Variable Stellar Parameter Estimation Using Residual Multitask Neural Networks

Authors: Bruno Santos Meneses Barreto, Marcio Eisencraft
Comments: This manuscript has been submitted to the Congresso Brasileiro de Automática (CBA) and is currently under peer review
Primary Category: astro-ph.IM
All Categories: astro-ph.IM, cs.LG

We present an end-to-end pipeline for estimating stellar parameters from Sloan Digital Sky Survey Data Release 12 spectra using a fully connected multitask neural network with residual blocks, whose hyperparameters are tuned via Bayesian optimization. The preprocessing pipeline includes per-spectrum standardization, RobustScaler normalization of the target variables -- effective temperature $T_{\mathrm{eff}}$, metallicity $[\mathrm{Fe/H}]$, and surface gravity $\log g$ -- and data augmentation via Gaussian noise injection. On a held-out test set, the model achieved Mean Absolute Errors (MAE) of $59.76~\mathrm{K}$ for $T_{\mathrm{eff}}$, $0.103~\mathrm{dex}$ for $[\mathrm{Fe/H}]$, and $0.130~\mathrm{dex}$ for $\log g$. Normalized against the full-scale range of each parameter, these results represent range-normalized errors between $1\%$ and $3\%$, achieved with a highly efficient model complexity of approximately 540,000 trainable parameters. These results demonstrate that a compact residual multitask architecture, combined with principled signal preprocessing, provides a parameter-efficient solution for nonlinear parameter estimation in large-scale spectral datasets. In particular, the proposed model achieves competitive performance with substantially lower complexity than deeper neural network baselines.


AI can help scientists publish less

Authors: Gianfranco Bertone
Comments: 7 pages, no figures
Primary Category: physics.soc-ph
All Categories: physics.soc-ph, astro-ph.IM, cs.AI

We can do more than defend science from a flood of AI-assisted papers. Used well, AI offers a historic opportunity to correct distortions in the publication system, help us publish fewer and better papers, and give scientists back the time to do their best work.