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In this work we investigate the nonlinear and nonlocal relation between cosmological density and peculiar velocity fields. Our goal is to provide an algorithm for the recon- struction of the nonlinear velocity field from the fully nonlinear…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Francisco-Shu Kitaura , Raul E. Angulo , Yehuda Hoffman , Stefan Gottl"ober

We present an analysis of the two-point peculiar velocity correlation function using data from the CosmicFlows catalogues. The Millennium and MultiDark Planck 2 N-body simulations are used to estimate cosmic variance and uncertainties due…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-24 Yuyu Wang , Christopher Rooney , Hume A. Feldman , Richard Watkins

The nonrelativistic limit of nonlocal modifications to the Klein Gordon operator is studied, and the experimental possibilities of casting stringent constraints on the nonlocality scale via planned and/or current optomechanical experiments…

General Relativity and Quantum Cosmology · Physics 2017-02-01 Alessio Belenchia , Dionigi M. T. Benincasa , Stefano Liberati , Francesco Marin , Francesco Marino , Antonello Ortolan

The two-point statistics of the cosmic velocity field, measured from galaxy peculiar velocity (PV) surveys, can be used as a dynamical probe to constrain the growth rate of large-scale structures in the universe. Most works use the…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-07 Motonari Tonegawa , Stephen Appleby , Changbom Park , Sungwook E. Hong , Juhan Kim

In this paper, we investigate the freezing quintessence scenario in late-time cosmic expansion using a non-linear $f(R, L_m)$ gravity model, $f(R,L_m)=\frac{R}{2}+L_m^\alpha$, where $\alpha$ is a free parameter. We consider a solution for…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-17 Yerlan Myrzakulov , M. Koussour , A. Caliskan , E. Güdekli , S. Muminov , J. Rayimbaev

We investigate the feasibility of carrying out likelihood analysis on the velocities of galaxy clusters to determine power spectrum parameters. Using N-body simulations of cosmological density fields we show that the velocity field traced…

Astrophysics · Physics 2007-05-23 Rupert Croft , George Efstathiou

In this letter, we investigate the cosmic expansion scenario of the universe in the framework of $f(R,L_m)$ gravity theory. We consider a non-linear $f(R,L_m)$ model, specifically, $f(R,L_m)=\frac{R}{2}+L_m^n + \beta$, where $n$ and $\beta$…

General Relativity and Quantum Cosmology · Physics 2023-11-02 Lakhan V. Jaybhaye , Raja Solanki , Sanjay Mandal , P. K. Sahoo

The spherical infall model first developed by Lema\^{i}tre and Tolman was modified in order to include the effects of a dark energy term. The resulting velocity-distance relation was evaluated numerically. This equation, when fitted to…

Astrophysics · Physics 2016-08-16 Sébastien Peirani , José Antonio De Freitas Pacheco

We investigate the evolution of cosmic structures within the framework of modified gravity, specifically focusing on theories described by the function $f(R, L_m)$, where $R$ is the Ricci scalar and $L_m$ is the matter Lagrangian. This…

General Relativity and Quantum Cosmology · Physics 2025-07-08 G. K. Goswami , J. P. Saini

We investigate the influence of bulk viscosity on late-time cosmic acceleration within an extended $f(Q, L_m)$ gravity framework, where the non-metricity $Q$ is non-minimally coupled with the matter Lagrangian $L_m$. Analyzing the function…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-05 Y. Myrzakulov , O. Donmez , M. Koussour , S. Muminov , I. Y. Davletov , J. Rayimbaev

The classic model of the Local Group (LG) is that of two dominant constituents, the Milky Way and M31, first separating and then detaching from the Hubble flow, leading to a nearly radial approaching orbit. This simple model has been…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Louis E. Strigari

A promising method for measuring the cosmological parameter combination fsigma_8 is to compare observed peculiar velocities with peculiar velocities predicted from a galaxy density field using perturbation theory. We use N-body simulations…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-03 Amber M. Hollinger , Michael J. Hudson

The homogeneous electron gas (HEG) is a key ingredient in the construction of most exchange-correlation functionals of density-functional theory. Often, the energy of the HEG is parameterized as a function of its spin density $n$, leading…

Chemical Physics · Physics 2021-02-10 Susi Lehtola , Miguel A. L. Marques

We investigate $f\left( Q\right) $-gravity with a matter-gravity coupling as a geometric dark energy candidate for the description of the late-time cosmic acceleration within a spatially flat Friedmann--Lema\^{\i}tre-Robertson-Walker…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Andronikos Paliathanasis

Basing on the increasing evidence for the cosmological relevance of the local Hubble flow, we consider a simple analytical cosmological model for the Local Universe. This is a non-Friedmann model with a non-uniform static space-time. The…

Astrophysics · Physics 2009-11-11 Arthur D. Chernin , Pekka Teerikorpi , Yurij V. Baryshev

Projection-free conditional gradient (CG) methods are the algorithms of choice for constrained optimization setups in which projections are often computationally prohibitive but linear optimization over the constraint set remains…

Optimization and Control · Mathematics 2021-06-17 Alejandro Carderera , Jelena Diakonikolas , Cheuk Yin Lin , Sebastian Pokutta

Structural and thermodynamic properties of ionic fluids are related to those of a simpler ``mimic'' system with short ranged intermolecular interactions in a spatially varying effective field by use of Local Molecular Field (LMF) theory,…

Statistical Mechanics · Physics 2007-05-23 Yng-gwei Chen , Charanbir Kaur , John D. Weeks

Even if the fundamental action of gravity is local, the corresponding quantum effective action, that includes the effect of quantum fluctuations, is a nonlocal object. These nonlocalities are well understood in the ultraviolet regime but…

High Energy Physics - Theory · Physics 2018-03-21 Enis Belgacem , Yves Dirian , Stefano Foffa , Michele Maggiore

Using N-body simulations of flat, dark energy dominated cosmologies, we show that galaxies around simulated binary systems resembling the Local Group (LG) have low peculiar velocities, in good agreement with observational data. We have…

Astrophysics · Physics 2009-11-10 Andrea V. Maccio' , Fabio Governato , Cathy Horellou

A phenomenological formalism is presented in which the apparent acceleration of the universe is generated by large-scale structure formation, thus eliminating the magnitude and coincidence fine-tuning problems of the Cosmological Constant…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Brett Bochner