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Studies of the growth of cosmic perturbations are typically focused on galactic scales and above. In this paper we investigate the evolution of perturbations in baryons, photons, and dark matter for masses below 10^6 M_\odot (or wavenumbers…

Astrophysics · Physics 2009-11-07 Shwetabh Singh , Chung-Pei Ma

We analyze cosmological perturbations to the linear order in the context of inflation with an arbitrary number of scalar fields. The fields take values on a non-trivial manifold with a positive-definite metric and are non-minimally coupled…

Astrophysics · Physics 2007-05-23 Joydev Lahiri , Gautam Bhattacharya

A better understanding of the formation of large-scale structure in the Universe is arguably the most pressing question in cosmology. The most compelling and promising theoretical paradigm, Inflation + Cold Dark Matter, holds that the…

Astrophysics · Physics 2009-10-30 Michael S. Turner

By efforts of several authors, it is recently established that the dynamical behavior of the cosmological perturbation on superhorizon scales is well approximated in terms of that in the long wavelength limit, and the latter can be…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Takashi Hamazaki

It is shown that a first-order cosmological perturbation theory for the open, flat and closed Friedmann-Lema\^itre-Robertson-Walker universes admits one, and only one, gauge-invariant variable which describes the perturbation to the energy…

General Relativity and Quantum Cosmology · Physics 2014-10-02 P. G. Miedema , W. A. van Leeuwen

We consider the growth of cosmological perturbations to the energy density of dark matter during matter domination when dark matter is a scalar field that has undergone Bose-Einstein condensation. We study these inhomogeneities within the…

High Energy Physics - Phenomenology · Physics 2015-06-03 Ben Kain , Hong Y. Ling

We present a simple heuristic model to demonstrate how feedback related to the galaxy formation process can result in a scale-dependent bias of mass versus light, even on very large scales. The model invokes the idea that galaxies form…

Astrophysics · Physics 2008-11-26 Peter Coles , Pirin Erdogdu

We estimate the amount of vorticity generated at second order in cosmological perturbation theory from the coupling between first order energy density and non-adiabatic pressure, or entropy, perturbations. Assuming power law input spectra…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-24 Adam J. Christopherson , Karim A. Malik , David R. Matravers

It is shown that the evolution of the density perturbations during certain eras of substantial entropy generation in the universe can be described in the scheme of the KPZ equation. Therefore, the influence on cosmological structure…

Astrophysics · Physics 2009-10-22 A. Berera , L. Z. Fang

A brief account is given of large-scale structure modelling based on the assumption that the initial perturbations arise from inflation. A recap is made of the implications of inflation for large-scale structure; under the widely applicable…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

In this letter, we discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the…

Astrophysics · Physics 2009-11-10 Keitaro Takahashi , Kiyotomo Ichiki , Hiroshi Ohno , Hidekazu Hanayama

We investigate a conformal invariant gravitational model which is taken to hold at pre-inflationary era. The conformal invariance allows to make a dynamical distinction between the two unit systems (or conformal frames) usually used in…

High Energy Physics - Theory · Physics 2009-11-10 Yousef Bisabr

We present a simple calculation leading to the quantum gravitationally-induced decoherence of a spatial superposition of a massive object in the linear coupling regime. The point of this calculation is to illustrate that the…

Quantum Physics · Physics 2020-06-01 Vlatko Vedral

The generation of large-scale magnetic fields is studied in dilaton electromagnetism in inflationary cosmology, taking into account the dilaton's evolution throughout inflation and reheating until it is stabilized with possible entropy…

Astrophysics · Physics 2008-11-26 Kazuharu Bamba , J. Yokoyama

In simple inflationary cosmological scenarios the near-exponential growth can be followed by a long period in which the Universe is dominated by the oscillating inflaton condensate. The condensate is initially almost homogeneous, but…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-19 Nathan Musoke , Shaun Hotchkiss , Richard Easther

Cosmological issues of the gravitino production by the decay of a heavy scalar field $X$ are examined, assuming that the damped coherent oscillation of the scalar once dominates the energy of the universe. The coupling of the scalar field…

High Energy Physics - Phenomenology · Physics 2009-11-11 Takehiko Asaka , Shuntaro Nakamura , Masahiro Yamaguchi

Cosmologies with running cosmological term (Lambda) and gravitational Newton's coupling (G) may naturally be expected if the evolution of the universe can ultimately be derived from the first principles of Quantum Field Theory or String…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Javier Grande , Joan Sola , Julio C. Fabris , Ilya L. Shapiro

We show the existence of a general mechanism by which heavy scalar fields can be destabilized during inflation, relying on the fact that the curvature of the field space manifold can dominate the stabilizing force from the potential and…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-05 Sébastien Renaux-Petel , Krzysztof Turzyński

We revisit the study of the phenomenology associated to a burst of particle production of a field whose mass is controlled by the inflaton field and vanishes at one given instance during inflation. This generates a bump in the correlators…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-14 Lauren Pearce , Marco Peloso , Lorenzo Sorbo

The dynamics of expansion of the Universe and evolution of scalar perturbations are studied for the quintessential scalar fields $Q$ with the classical Lagrangian satisfying the additional condition $w=const$ or $c^2_a=0$. Both…

Astrophysics · Physics 2009-08-10 B. Novosyadlyj , O. Sergijenko