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Related papers: On distance and velocity estimation in cosmology

200 papers

The existence of 'peculiar' velocities due to the formation of cosmic structure marks a point of discord between the real Universe and the usually assumed Friedmann-Lema\'{i}tre-Robertson-Walker metric which accomodates only the smooth…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-09 Roya Mohayaee , Mohamed Rameez , Subir Sarkar

To study the early Universe, it is essential to estimate cosmological parameters with high accuracy, which depends on the optimal reconstruction of Cosmic Microwave Background (CMB) maps and the measurement of their power spectrum. In this…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-10 Belén Costanza , Claudia G. Scóccola , Matías Zaldarriaga

Motivated by the dawn of precision cosmology and the wealth of forthcoming high precision and volume galaxy surveys, in this paper we study the effects of inhomogeneities on light propagation in a flat \Lambda CDM background. To this end we…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Nikolai Meures , Marco Bruni

The distance-redshift relation plays an important role in cosmology. In the standard approach to cosmology it is assumed that this relation is the same as in the homogeneous universe. As the real universe is not homogeneous there are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Krzysztof Bolejko

Model misspecification constitutes a major obstacle to reliable inference in many inverse problems. Inverse problems in seismology, for example, are particularly affected by misspecification of wave propagation velocities. In this paper, we…

Methodology · Statistics 2021-05-18 Andrea Scarinci , Michael Fehler , Youssef Marzouk

Distances are pervasive in machine learning. They serve as similarity measures, loss functions, and learning targets; it is said that a good distance measure solves a task. When defining distances, the triangle inequality has proven to be a…

Machine Learning · Computer Science 2020-07-08 Silviu Pitis , Harris Chan , Kiarash Jamali , Jimmy Ba

The large scale structure of the universe is reconstructed by means of the Wiener filter and constrained realizations of Gaussian fields. The density field constructed from optically selected galaxies (Hudson \cite{Hudson}) has been sampled…

Astrophysics · Physics 2007-05-23 Y. Hoffman

Galaxy cluster masses, rich with cosmological information, can be estimated from internal dark matter (DM) velocity dispersions, which in turn can be observationally inferred from satellite galaxy velocities. However, galaxies are biased…

We have combined five Tully-Fisher (TF) redshift-distance samples for peculiar velocity analysis: the cluster data of Han, Mould and coworkers (1991-93, HM) and Willick (1991, W91CL), and the field data of Aaronson et al. (1992), Willick…

Estimating the diagonal entries of a matrix, that is not directly accessible but only available as a linear operator in the form of a computer routine, is a common necessity in many computational applications, especially in image…

Instrumentation and Methods for Astrophysics · Physics 2015-03-19 Marco Selig , Niels Oppermann , Torsten A. Enßlin

If the voids that we see today in the distribution of galaxies existed at recombination, they will leave an imprint on the cosmic microwave background (CMB). On the other hand, if these voids formed much later, their effect on the CMB will…

Astrophysics · Physics 2009-11-10 Louise M. Ord , Martin Kunz , Hugues Mathis , Joseph Silk

The cosmic distance scale is built on multiple different techniques for estimating distances in space that are often connected and dependent on multiple measurements and assumptions. Double white dwarf binaries (DWDs) are common objects and…

High Energy Astrophysical Phenomena · Physics 2026-02-12 Yuetong Zhao , L. Hellström , Siqi Zhang , M. Giersz , A. Askar , Youjun Lu , Zhoujian Cao , D. Belloni , G. Wiktorowicz , M. Górski

Applications in data science, shape analysis and object classification frequently require comparison of probability distributions defined on different ambient spaces. To accomplish this, one requires a notion of distance on a given class of…

Metric Geometry · Mathematics 2022-07-19 Facundo Mémoli , Tom Needham

Using redshifts as a proxy for galaxy distances, estimates of the 2D transverse peculiar velocities of distant galaxies could be obtained from future measurements of proper motions. We provide the mathematical framework for analyzing 2D…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Adi Nusser , Enzo Branchini , Marc Davis

We study the non-convex optimization landscape for maximum likelihood estimation in the discrete orbit recovery model with Gaussian noise. This model is motivated by applications in molecular microscopy and image processing, where each…

Statistics Theory · Mathematics 2021-03-02 Zhou Fan , Yi Sun , Tianhao Wang , Yihong Wu

We consider the problem of reconstructing the intrinsic geometry of a manifold from noisy pairwise distance observations. Specifically, let $M$ denote a diameter 1 d-dimensional manifold and $\mu$ a probability measure on $M$ that is…

Machine Learning · Statistics 2025-11-18 Charles Fefferman , Jonathan Marty , Kevin Ren

On small scales the observable Universe is highly inhomogeneous, with galaxies and clusters forming a complex web of voids and filaments. The optical properties of such configurations can be quite different from the perfectly smooth…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Viraj A. A. Sanghai , Pierre Fleury , Timothy Clifton

This paper investigates the inverse scattering problem of time-harmonic plane waves incident on a perfectly reflecting random periodic structure. To simulate random perturbations arising from manufacturing defects and surface wear in…

Numerical Analysis · Mathematics 2025-07-29 Zhiqi Sun , Yiwen Lin

In this paper, we relate the framework of mod-$\phi$ convergence to the construction of approximation schemes for lattice-distributed random variables. The point of view taken here is that of Fourier analysis in the Wiener algebra, allowing…

Probability · Mathematics 2020-07-06 Reda Chhaibi , Freddy Delbaen , Pierre-Loïc Méliot , Ashkan Nikeghbali

The peculiar velocity reconstruction methods allow one to have a deeper insight into the distribution of dark matter: both to measure mean matter density and to obtain the primordial density fluctuations. We present here the…

Astrophysics · Physics 2015-05-13 G. Lavaux , R. Mohayaee , S. Colombi , R. B. Tully