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Only certain galaxies are included in surveys: those bright and large enough to be detectable as extended sources. Because gravitational lensing can make galaxies appear both brighter and larger, the presence of foreground inhomogeneities…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Fabian Schmidt , Eduardo Rozo , Scott Dodelson , Lam Hui , Erin Sheldon

Cosmological parameter estimation from forthcoming experiments promise to reach much greater precision than current constraints. As statistical errors shrink, the required control over systematic errors increases. Therefore, models or…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 José Luis Bernal , Nicola Bellomo , Alvise Raccanelli , Licia Verde

We present a quantum algorithm for efficiently sampling transformed Gaussian random fields on $d$-dimensional domains, based on an enhanced version of the classical moving average method. Pointwise transformations enforcing boundedness are…

Quantum Physics · Physics 2025-08-20 Matthias Deiml , Daniel Peterseim

A fraction of the XMM-Newton/EPIC FOV is obscured by the dysfunctional (i.e. bad) pixels. The fraction varies between different EPIC instruments in a given observation. These complications affect the analysis of extended X-ray sources…

Instrumentation and Methods for Astrophysics · Physics 2021-03-03 J. Nevalainen , I. Valtchahov , R. D. Saxton , S. Molendi

When comparing 2D shapes, a key issue is their normalization. Translation and scale are easily taken care of by removing the mean and normalizing the energy. However, defining and computing the orientation of a 2D shape is not so simple. In…

Computer Vision and Pattern Recognition · Computer Science 2015-05-20 João B. F. P. Crespo , Pedro M. Q. Aguiar

In many real-world binary classification tasks (e.g. detection of certain objects from images), an available dataset is imbalanced, i.e., it has much less representatives of a one class (a minor class), than of another. Generally, accurate…

Machine Learning · Statistics 2017-07-14 Evgeny Burnaev , Pavel Erofeev , Artem Papanov

Confirmation bias, the tendency to interpret information in a way that aligns with one's preconceptions, can profoundly impact scientific research, leading to conclusions that reflect the researcher's hypotheses even when the observational…

Machine Learning · Statistics 2025-09-09 Amnon Balanov , Tamir Bendory , Wasim Huleihel

Upcoming and ongoing large area weak lensing surveys will also discover large samples of galaxy clusters. Accurate and precise masses of galaxy clusters are of major importance for cosmology, for example, in establishing well calibrated…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-24 F. Köhlinger , H. Hoekstra , M. Eriksen

In recent years, gravitational lensing has been used as a means to detect substructure in galaxy-sized halos, via anomalous flux ratios in quadruply-imaged lenses. In addition to causing anomalous flux ratios, substructure may also perturb…

Astrophysics · Physics 2011-02-11 Jacqueline Chen , Eduardo Rozo , Neal Dalal , James E. Taylor

To measure the mass of foreground objects with weak gravitational lensing, one needs to estimate the redshift distribution of lensed background sources. This is commonly done in an empirical fashion, i.e. with a reference sample of galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Daniel Gruen , Fabrice Brimioulle

Spatial regression of random fields based on potentially biased sensing information is proposed in this paper. One major concern in such applications is that since it is not known a-priori what the accuracy of the collected data from each…

Signal Processing · Electrical Eng. & Systems 2020-09-04 Qikun Xiang , Ido Nevat , Gareth W. Peters

Subsampling algorithms for various parametric regression models with massive data have been extensively investigated in recent years. However, all existing studies on subsampling heavily rely on clean massive data. In practical…

Statistics Theory · Mathematics 2025-06-11 Jiangshan Ju , Mingqiu Wang , Shengli Zhao

We follow the evolution with sample thickness, of intensity statistics for localized light transmitted through layered media in a crossover from one to three dimensions occasioned by transverse disorder. The probability distribution of…

Disordered Systems and Neural Networks · Physics 2013-05-29 Jongchul Park , Sheng Zhang , Azriel Z. Genack

The combination of two- and three-point clustering statistics of galaxies and the underlying matter distribution has the potential to break degeneracies between cosmological parameters and nuisance parameters and can lead to significantly…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Oliver Leicht , Tobias Baldauf , James Fergusson , Paul Shellard

The network flow optimization approach is offered for Bayesian segmentation of gray-scale and color images. It is supposed image pixels are characterized by a feature function taking finite number of arbitrary rational values (it can be…

Statistics Theory · Mathematics 2016-09-07 B. A. Zalesky

Observations of the clustering of galaxies can provide useful information about the distribution of dark matter in the Universe. In order to extract accurate cosmological parameters from galaxy surveys, it is important to understand how the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Surhud More

We qualitatively examine properties of artificial deformation in shapes of objects (galaxies and stars) induced by the pixelization effects (also called as the aliasing effects) using toy mock simulation images. We pay a special attention…

Astrophysics · Physics 2015-05-13 Takashi Hamana , Satoshi Miyazaki

Measuring the centroid of a spectral line is a common problem in astronomy. Many methods have been devised to overcome limitations due to either noise in the spectra or asymmetric profiles, the most common of which are the intensity…

Instrumentation and Methods for Astrophysics · Physics 2018-09-28 Richard Teague , Daniel Foreman-Mackey

We present results from an end-to-end simulation pipeline interferometric observations of cosmic microwave background polarization. We use both maximum-likelihood and Gibbs sampling techniques to estimate the power spectrum. In addition, we…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-15 Emory F. Bunn , Ata Karakci , Paul M. Sutter , Le Zhang , Gregory S. Tucker , Peter T. Timbie , Benjamin D. Wandelt

This article considers the detection of point sources in two dimensional astronomical images. The detection scheme we propose is based on peak statistics. We discuss the example of the detection of far galaxies in Cosmic Microwave…

Astrophysics · Physics 2009-11-10 M. Lopez-Caniego , D. Herranz , J. L. Sanz , R. B. Barreiro