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When density fluctuations collapse gravitationally out of the expanding cosmological background universe to form galaxies, the secondary energy release which results can affect their subsequent evolution profoundly. We focus here on the…

Astrophysics · Physics 2007-05-23 Hugo Martel , Paul R. Shapiro

The cosmon field responsible for dynamical dark energy can induce an inflationary period in early cosmology. Details depend on dilatation symmetry breaking terms in its potential and kinetic term that are relevant only during early stages…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 C. Wetterich

Super-homogeneity is a property that is supposed to be satisfied by matter fluctuations in all standard theoretical models of structure formation, such as LCDM and its variants. This is a global condition on the correlation properties of…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-15 Francesco Sylos Labini

The possibility that the universe may have a fundamental and positive cosmological constant has motivated an interesting cosmological model, in which initially the universe is in a cosmological constant sea, then the local quantum…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Yun-Song Piao

The initial conditions of cosmological simulations are commonly drawn from a Gaussian ensemble. The limited number of modes inside a simulation volume gives rise to statistical fluctuations known as \textit{sample variance}, limiting the…

According to the inflationary scenario for the very early Universe, all inhomogeneities in the Universe are of genuine quantum origin. On the other hand, looking at these inhomogeneities and measuring them, clearly no specific quantum…

General Relativity and Quantum Cosmology · Physics 2009-10-31 C. Kiefer , D. Polarski , A. A. Starobinsky

During the evolution of density inhomogeneties in an $\Omega=1$, matter dominated universe, the typical density contrast changes from $\delta\simeq 10^{-4}$ to $\delta\simeq 10^2$. However, during the same time, the typical value of the…

General Relativity and Quantum Cosmology · Physics 2019-08-17 J. S. Bagla , T. Padmanabhan

In Part I of this series, we introduced the Spherical Collapse (SC) approximation in Lagrangian space as a way of estimating the cumulants $\xi_J$ of density fluctuations in cosmological Perturbation Theory (PT). Within this approximation,…

Astrophysics · Physics 2009-10-30 Enrique Gaztanaga , Pablo Fosalba

In this paper, we suppose that the universe begins in a holographic thermal equilibrium phase with the diverged correlation length, and the phase transition to the radiation phase of standard cosmology goes with the abrupt reducing of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yun-Song Piao

We study a universe filled with dust-like matter in the form of discrete inhomogeneities (e.g., galaxies and their groups and clusters) and two sets of perfect fluids with linear and nonlinear equations of state, respectively. The…

General Relativity and Quantum Cosmology · Physics 2016-09-21 Maxim Eingorn , Claus Kiefer , Alexander Zhuk

Primordial fluctuations in inflationary cosmology acquire classical properties through decoherence when their wavelengths become larger than the Hubble scale. Although decoherence is effective, it is not complete, so a significant part of…

Astrophysics · Physics 2008-11-26 C. Kiefer , I. Lohmar , D. Polarski , A. A. Starobinsky

The spatial and temporal noise properties of diffuse radiation is investigated in the context of the cosmic microwave background (CMB), although generic formulae that enable application to any other forms of incoherent light of a prescribed…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-02 Richard Lieu , Bizhu Jiang

In the early Universe, a dual component made of coupled CDM and a scalar field $\Phi$, if their coupling $\beta > \sqrt{3}/2$, owns an attractor solution, making them a stationary fraction of cosmic energy during the radiation dominated…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Silvio A. Bonometto , Roberto Mainini

The complete theory of cosmological evolution's macroscopic description is constructed with a help of self-consistent field. The theory includes a subsystem of linear equations of perturbations' evolution and nonlinear macroscopic Einstein…

General Relativity and Quantum Cosmology · Physics 2020-07-09 Yu. G. Ignat'ev

Based on a thoeretical model in which scalar fields play crucial roles, we propose a mechanism to better understand a cosmological constant expected to be small (nearly comparable with the critical density) but nonzero as suggested strongly…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Yasunori Fujii

The ordering dynamics of the Higgs field is studied, using techniques inspired by the study of phase ordering in condensed matter physics, as a first step to understanding the evolution of cosmic structure through the formation of…

High Energy Physics - Phenomenology · Physics 2009-10-28 Joao A. N. Filipe , Alan J. Bray

Following the discovery of the CMB, the hot big-bang model has become the standard cosmological model. In this theory, small primordial fluctuations are subsequently amplified by gravity to form the large-scale structure seen today.…

Astrophysics · Physics 2015-06-24 Licia Verde

We consider here the dynamics of some homogeneous and isotropic cosmological models with $N$ interacting classical scalar fields non-minimally coupled to the spacetime curvature, as an attempt to generalize some recent results obtained for…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. Brenig , A. Figueiredo , E. Gunzig , T. M. Rocha Filho , Alberto Saa

Conserved-charge densities are very special observables in quantum many-body systems as, by construction, they encode information about the dynamics. Therefore, their evolution is expected to be of much simpler interpretation than that of…

Statistical Mechanics · Physics 2024-05-30 Bruno Bertini , Katja Klobas , Mario Collura , Pasquale Calabrese , Colin Rylands

A Cahn-Hilliard-type theory for hydrodynamic fluctuations is proposed that gives a quantitative description of the slowly evolving spatial correlations and structures in density and flow fields in the early stages of evolution of freely…

Statistical Mechanics · Physics 2009-10-31 T. P. C. van Noije , M. H. Ernst