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While the $\Lambda$CDM model succeeds on large scales, its validity on smaller scales remains uncertain. Recent works suggest that non-halo dark matter structures, such as filaments and walls, could significantly influence gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Baptiste Jego , Giulia Despali , Tamara Richardson , Jens Stücker

Length scales probed by large scale structure surveys are becoming closer to the horizon scale. Further, it has been recently understood that non-Gaussianity in the initial conditions could show up in a scale dependence of the bias of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Tobias Baldauf , Uros Seljak , Leonardo Senatore , Matias Zaldarriaga

The density profiles of dark matter haloes are commonly described by fitting functions such as the NFW or Einasto models, but these approximations break down in the transition region where halos become dominated by newly accreting matter.…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-10 Benedikt Diemer

We present a new gravitational lens modelling technique designed to model high-resolution interferometric observations with large numbers of visibilities without the need to pre-average the data in time or frequency. We demonstrate the…

Instrumentation and Methods for Astrophysics · Physics 2021-01-06 Devon Powell , Simona Vegetti , John P. McKean , Cristiana Spingola , Francesca Rizzo , Hannah R. Stacey

Non-parametric lensing methods are a useful way of reconstructing the lensing mass of a cluster without making assumptions about the way the mass is distributed in the cluster. These methods are particularly powerful in the case of galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Pier Paolo Ponente , Jose Maria Diego

The degeneracy between disc and halo contributions in spiral galaxy rotation curves makes it difficult to obtain a full understanding of the distribution of baryons and dark matter in disc galaxies like our own Milky Way. Using mock data,…

Astrophysics of Galaxies · Physics 2019-03-27 Samantha Scibelli , Rosalba Perna , Charles Keeton

The distribution of galaxies, halo abundance, and peculiar velocities are influenced by non-linear gravitational interactions, making the study of non-linear evolution crucial for accurate cosmological predictions. We explore these aspects…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 Swati Gavas

Standard cosmic microwave background (CMB) analyses constrain cosmological and astrophysical parameters by fitting parametric models to multifrequency power spectra (MFPS). However, such methods do not optimally weight maps in power…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Kristen M. Surrao , J. Colin Hill

We use the statistics of strong gravitational lensing from the CLASS survey to impose constraints on the velocity dispersion and density profile of elliptical galaxies. This approach differs from much recent work, where the luminosity…

Astrophysics · Physics 2009-11-07 Adam N. Davis , Dragan Huterer , Lawrence M. Krauss

This is the first paper of a series aiming at investigating galaxy formation and evolution in the giant-void class of the Lemaitre-Tolman-Bondi (LTB) models that best fits current cosmological observations. Here we investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-18 A. Iribarrem , P. Andreani , C. Gruppioni , S. February , M. B. Ribeiro , S. Berta , E. Le Floc'h , B. Magnelli , R. Nordon , P. Popesso , F. Pozzi , L. Riguccini

Nonnegative matrix factorization (NMF) seeks a low-rank approximation $X \approx UV^T$ with nonnegative factors and is commonly solved using interior methods that enforce feasibility throughout optimization. We show that such…

Machine Learning · Computer Science 2026-05-20 Qiujing Lu , Tonmoy Monsoor , Ehsan Ebrahimzadeh , Kartik Sharma , Vwani Roychowdhury

Correlations between intrinsic ellipticities of galaxies are a potentially important systematic error when constraining dark energy properties from weak gravitational lensing (cosmic shear) surveys. In the absence of perfectly known galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Michael D. Schneider , Sarah Bridle

The distribution of mass on galaxy cluster scales is an important test of structure formation scenarios, providing constraints on the nature of dark matter itself. Several techniques have been used to probe the mass distributions of…

Astrophysics · Physics 2009-11-11 Lindsay King , Virginia Corless

Modelling of the weak lensing of the CMB will be crucial to obtain correct cosmological parameter constraints from forthcoming precision CMB anisotropy observations. The lensing affects the power spectrum as well as inducing…

Astrophysics · Physics 2010-11-17 Antony Lewis

The Na\"ive Mean Field (NMF) approximation is widely employed in modern Machine Learning due to the huge computational gains it bestows on the statistician. Despite its popularity in practice, theoretical guarantees for high-dimensional…

Statistics Theory · Mathematics 2023-10-17 Jiaze Qiu

We seek to understand the impact on shape estimators obtained from circular and elliptical shapelet models under two realistic conditions: (a) only a limited number of shapelet modes is available for the model, and (b) the intrinsic…

Instrumentation and Methods for Astrophysics · Physics 2014-07-24 P. Melchior , A. Boehnert , M. Lombardi , M. Bartelmann

We present a new technique to constrain the gravitational potential of a galaxy from the observed stellar mass surface density alone under a number of assumptions. It uses the classical Eddington Inversion Method to compute the phase-space…

Astrophysics of Galaxies · Physics 2025-02-19 Jorge Sanchez Almeida , Ignacio Trujillo , Mireia Montes , Angel R. Plastino

We present a unified parameterization of the fitting functions suitable for density profiles of dark matter haloes or elliptical galaxies. A notable feature is that the classical Einasto profile appears naturally as the continuous limiting…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-30 J. An , H. Zhao

Density fluctuations in the matter distribution lead to distortions of the images of distant galaxies through weak gravitational lensing effects. This provides an efficient probe of the cosmological parameters and of the density field. In…

Astrophysics · Physics 2007-05-23 P. Valageas

The fraction of high-redshift sources which are multiply-imaged by intervening galaxies is strongly dependent on the cosmological constant, and so can be a useful probe of the cosmological model. However its power is limited by various…

Astrophysics · Physics 2009-10-31 Daniel J. Mortlock , Rachel L. Webster