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We study evolution of voids in cosmological simulations using a new method for tracing voids over cosmic time. The method is based on tracking watershed basins (contiguous regions around density minima) of well developed voids at low…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Radosław Wojtak , Devon Powell , Tom Abel

We calculate the cosmological evolution of the 1-point probability distribution function (PDF), using an analytic approximation that combines gravitational perturbation theory with the Edgeworth expansion of the PDF. Our method applies…

Astrophysics · Physics 2009-10-22 R. Juszkiewicz , D. Weinberg , P. Amsterdamski , M. Chodorowski , F. Bouchet

In this paper, we study the evolution of a relativistic, superhorizon-sized void embedded in a Friedmann-Robertson-Walker universe. We numerically solve the spherically symmetric general relativistic equations in comoving, synchronous…

High Energy Physics - Phenomenology · Physics 2009-10-22 Sharon L. Vadas

We investigate the virialization of cosmic structures in the framework of flat FLRW cosmological models, in which the vacuum energy density evolves with time. In particular, our analysis focuses on the study of spherical matter…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 S. Basilakos , M. Plionis , J. Sola

We present a new perspective on the symmetries that govern the formation of large-scale structures across the Universe, particularly focusing on the transition from the seeds of galaxy clusters to the seeds of galaxies themselves. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-28 Giovanni Montani , Nakia Carlevaro

We develop an analysis pipeline for characterizing the topology of large scale structure and extracting cosmological constraints based on persistent homology. Persistent homology is a technique from topological data analysis that quantifies…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-14 Matteo Biagetti , Alex Cole , Gary Shiu

We study the structure formation by investigating the spherical collapse model in the context of new agegraphic dark energy model in flat FRW cosmology. We compute the perturbational quantities $g(a)$, $\delta_{c}(z_{c})$, $\lambda(z_{c})$,…

General Relativity and Quantum Cosmology · Physics 2017-07-05 M. R. Setare , F. Felegary , F. Darabi

First order perturbations of homogeneous and hypersurface orthogonal LRS (Locally Rotationally Symmetric) class II cosmologies with a cosmological constant are considered in the framework of the 1+1+2 covariant decomposition of spacetime.…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Robin Törnkvist , Michael Bradley

We use very high resolution cosmological zoom simulations to follow the early evolution of twelve first-generation haloes formed from gaussian initial conditions with scale-free power spectra truncated on small scales by a gaussian in…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-29 M. Sten Delos , Simon D. M. White

The initial state of the spherical gravitational collapse in general relativity has been studied with different methods, especially by using {\it a priori} given equations of state that describe the matter as a perfect fluid. We propose an…

General Relativity and Quantum Cosmology · Physics 2024-10-24 Elly Bayona , Hernando Quevedo , Miguel Alcubierre

A numerical and dimensional correlation supported by reported literature experimental evidence (Homes, Harshmann along with Voyager, EGRET, FERMI, WMAP, Planck and other space platforms) is presented which indicates that superconductivity…

General Physics · Physics 2018-12-10 Richard D. Saam

We investigate the hydrodynamics of the interaction of two supersonic winds in binary systems. The collision of the winds creates two shocks separated by a contact discontinuity. The overall structure depends on the momentum flux ratio eta…

Solar and Stellar Astrophysics · Physics 2015-05-30 Astrid Lamberts , Sebastien Fromang , Guillaume Dubus

Understanding the structure of the matter distribution in the Universe due to the action of the gravitational instability -- the cosmic web -- is complicated by lack of direct analytic access to the nonlinear domain of structure formation.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Sergei Shandarin , Salman Habib , Katrin Heitmann

This paper aims to investigate the influence of inhomogeneous radiation in void formation. Since the process of void formation is non-linear, a fully relativistic model, which simulates the evolution of voids from the moment of the last…

Astrophysics · Physics 2009-11-10 Krzysztof Bolejko

At a time when galaxy surveys and other observations are reaching unprecedented sky coverage and precision it seems timely to investigate the effects of general relativistic nonlinear dynamics on the growth of structures and on…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-04 Nikolai Meures , Marco Bruni

In this paper, we present a simulation method within the two-component spherical collapse model to investigate dark energy perturbations associated with the formation of dark matter halos. The realistic mass accretion history of a dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Qiao Wang , Zuhui Fan

Recent measurements of hot and cold spots on the cosmic microwave background (CMB) sky suggest a presence of super-structures on (>100 h^{-1}Mpc) scales. We develop a new formalism to estimate the expected amplitude of temperature…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-20 Kaiki Taro Inoue , Nobuyuki Sakai , Kenji Tomita

The present work deals with the spherical collapse of matter overdensity for two reconstructed dark energy models. One of the models is reconstructed from parametrization of effective or total equation of state of energy components in the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-18 Ankan Mukherjee

This paper examines the growth of dark matter and dark energy perturbations within a non-canonical scalar field model characterized by an exponential potential. Through dynamical system analysis, we identify critical points and track the…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Zanyar Ebrahimi , Kayoomars Karami

We review the main theoretical aspects of the structure formation paradigm which impinge upon wide angle surveys: the early universe generation of gravitational metric fluctuations from quantum noise in scalar inflaton fields; the well…

Astrophysics · Physics 2007-05-23 J. R. Bond , L. Kofman , D. Pogosyan , J. Wadsley
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