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High-dimensional data must be highly structured to be learnable. Although the compositional and hierarchical nature of data is often put forward to explain learnability, quantitative measurements establishing these properties are scarce.…

Machine Learning · Statistics 2025-03-04 Antonio Sclocchi , Alessandro Favero , Noam Itzhak Levi , Matthieu Wyart

We introduce new methods for robust high-precision photometry from well-sampled images of a non-crowded field with a strongly varying point-spread function. For this work, we used archival imaging data of the open cluster M37 taken by MMT…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 S. -W. Chang , Y. -I. Byun , J. D. Hartman

Space-based transit search missions such as Kepler are collecting large numbers of stellar light curves of unprecedented photometric precision and time coverage. However, before this scientific goldmine can be exploited fully, the data must…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 S. Roberts , A. McQuillan , S. Reece , S. Aigrain

Image registration is the process of transforming different sets of data into one coordinate system and is required for various remote sensing applications like change detection, image fusion, and other related areas. The effect of…

Computer Vision and Pattern Recognition · Computer Science 2013-03-28 Arun P. V. , Dr. S. K. Katiyar

Classifying transients based on multi band light curves is a challenging but crucial problem in the era of GAIA and LSST since the sheer volume of transients will make spectroscopic classification unfeasible. Here we present a nonparametric…

Instrumentation and Methods for Astrophysics · Physics 2015-10-26 Melvin M. Varughese , Rainer von Sachs , Michael Stephanou , Bruce A. Bassett

In this paper we make progress on the unsupervised task of mining arbitrarily shaped clusters in highly noisy datasets, which is a task present in many real-world applications. Based on the fundamental work that first applies a wavelet…

Databases · Computer Science 2019-01-08 Zengjian Chen , Jiayi Liu , Yihe Deng , Kun He , John E. Hopcroft

Purpose: Using linear transformation of the data allows studying detectability of an imaging system on a large number of signals. An appropriate transformation will produce a set of signals with different contrast and different frequency…

Medical Physics · Physics 2021-04-20 Antonio González-López

We present the results of an automated variability analysis of the Kepler public data measured in the first quarter (Q1) of the mission. In total, about 150 000 light curves have been analysed to detect stellar variability, and to identify…

Solar and Stellar Astrophysics · Physics 2015-05-27 J. Debosscher , J. Blomme , C. Aerts , J. De Ridder

Although unsupervised generative modeling of an image dataset using a Variational AutoEncoder (VAE) has been used to detect anomalous images, or anomalous regions in images, recent works have shown that this method often identifies images…

Computer Vision and Pattern Recognition · Computer Science 2020-08-13 David Dehaene , Pierre Eline

Examining the detailed structure of galaxy populations provides valuable insights into their formation and evolution mechanisms. Significant barriers to such analysis are the non-trivial noise properties of real astronomical images and the…

Instrumentation and Methods for Astrophysics · Physics 2023-12-01 Alexandre Adam , Connor Stone , Connor Bottrell , Ronan Legin , Yashar Hezaveh , Laurence Perreault-Levasseur

Since the variety of their light curve morphologies, the vast majority of the known heartbeat stars (HBSs) have been discovered by manual inspection. Machine learning, which has already been successfully applied to the classification of…

Solar and Stellar Astrophysics · Physics 2025-08-15 Min-Yu Li , Sheng-Bang Qian , Li-Ying Zhu , Wen-Ping Liao , Lin-Feng Chang , Er-Gang Zhao , Xiang-Dong Shi , Fu-Xing Li , Qi-Bin Sun , Ping Li

We consider the problem of detecting the presence of a spatially correlated multichannel signal corrupted by additive Gaussian noise (i.i.d across sensors). No prior knowledge is assumed about the system parameters such as the noise…

Information Theory · Computer Science 2013-04-19 Vidyadhar Upadhya , Devendra Jalihal

The signatures of waves are seen during many high-quality ground-based refractive stellar occultations by solar system atmospheres. We present a new forward-modeling technique for ground-based stellar occultations based on wavelet…

Earth and Planetary Astrophysics · Physics 2025-09-15 Leslie A. Young , Michael J. Person

We present the source separation framework SCARLET for multi-band images, which is based on a generalization of the Non-negative Matrix Factorization to alternative and several simultaneous constraints. Our approach describes the observed…

Instrumentation and Methods for Astrophysics · Physics 2018-08-14 Peter Melchior , Fred Moolekamp , Maximilian Jerdee , Robert Armstrong , Ai-Lei Sun , James Bosch , Robert Lupton

Data assimilation performance can be significantly impacted by biased noise in observations, altering the signal magnitude and introducing fast oscillations or discontinuities when the system lacks smoothness. To mitigate these issues, this…

Numerical Analysis · Mathematics 2024-11-05 Felipe Galarce , Joaquin Mura , Alfonso Caiazzo

Context. Images of spatially resolved astrophysical objects contain a wealth of morphological and dynamical information, and effective extraction of this information is of paramount importance for understanding the physics and evolution of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Florent Mertens , Andrei Lobanov

Aims: During its all-sky survey phase, the eROSITA X-ray telescope onboard SRG scans through the ecliptic poles every 4 hours. This extensive data set of long-duration, frequent, and consistent observations of thousands of X-ray sources is…

Instrumentation and Methods for Astrophysics · Physics 2024-07-03 David Bogensberger , Kirpal Nandra , Johannes Buchner

We provide a statistical analysis of the ability of digitized continuous shearlet systems to detect objects embedded in white noise. We analyze the possibility to subsample the shearlet transform and obtain a subset of significantly reduced…

Functional Analysis · Mathematics 2015-04-24 Philipp Petersen

We present a series of X-ray variability results from a long XMM-Newton + NuSTAR campaign on the bright, variable AGN NGC 3227. We present an analysis of the lightcurves, showing that the source displays typically softer-when-brighter…

High Energy Astrophysical Phenomena · Physics 2020-04-30 A. P. Lobban , T. J. Turner , J. N. Reeves , V. Braito , L. Miller

In this study, we demonstrate some of the caveats in common statistical methods used for analysing astronomical variability timescales. We consider these issues specifically in the context of active galactic nuclei (AGNs) and use a more…

Astrophysics of Galaxies · Physics 2024-12-12 Sofia Kankkunen , Merja Tornikoski , Talvikki Hovatta
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