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Related papers: Non-Gaussianity from Excited Initial Inflationary …

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This study focuses on generating and manipulating squeezed states with two external oscillators coupled by an InP HEMT transistor operating at cryogenic temperatures. First, the small-signal nonlinear model of the transistor at high…

Quantum Physics · Physics 2022-04-19 Ahmad Salmanogli

We analyze the onset of inflation for a simple single-field model when the system begins with significant inhomogeneities on length-scales shorter than the initial Hubble radius. We incorporate certain nonlinear interactions among the…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-17 Jolyon K. Bloomfield , Patrick Fitzpatrick , Kiriakos Hilbert , David I. Kaiser

In this work we revisit $\alpha$-Starobinsky inflation, also know as $E$-model, in the light of current CMB and LSS observations. The inflaton potential in the Einstein frame for this model contains a parameter $\alpha$ in the exponential,…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-11 Saisandri Saini , Akhilesh Nautiyal

Recent observational claims of magnetic fields stronger than $10^{-16}$ G in the extragalactic medium motivate a new look for their origin in the inflationary magnetogenesis models. In this work we shall review the constraints on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-02 Ricardo J. Z. Ferreira , Rajeev Kumar Jain , Martin S. Sloth

We study non-Gaussianity of density perturbations generated by an axionic curvaton, focusing on the case that the curvaton sits near the hilltop of the potential during inflation. Such hilltop curvatons can generate a red-tilted density…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-15 Masahiro Kawasaki , Takeshi Kobayashi , Fuminobu Takahashi

We investigate the stationary state of a model system evolving according to a modified focusing truncated nonlinear Schr\"odinger equation (NLSE) used to describe the envelope of Langmuir waves in a plasma. We restrict the system to have a…

Mathematical Physics · Physics 2015-05-14 Philippe Mounaix , Pierre Collet , Joel L. Lebowitz

In hybrid inflationary models, inflation ends by a sudden instability associated with a steep ridge in the potential. Here we argue that this feature can generate a large contribution to the curvature perturbation on observable scales. This…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-21 David Mulryne , David Seery , Daniel Wesley

We study the statistical descriptors for some cosmological inflationary models that allow us to get large levels of non-gaussianity and violations of statistical isotropy. Basically, we study two different class of models: a model that…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-05 Cesar A. Valenzuela-Toledo

The evolutions of the flat FLRW universe and its linear perturbations are studied systematically in the dressed metric approach of LQC. When it is dominated by the kinetic energy of the inflaton at the quantum bounce, the evolution of the…

General Relativity and Quantum Cosmology · Physics 2017-10-25 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng

A formula for the power spectrum of curvature perturbations having any initial conditions in inflation is obtained. Based on the physical conditions before inflation, the possibility exists that the initial state of scalar perturbations is…

High Energy Physics - Theory · Physics 2017-08-23 Shiro Hirai

Quantum fluctuations in the post inflationary Affleck-Dine baryogenesis model are studied. The squeezed states formalism is used to give evolution equations for the particle and anti-particle modes in the early universe. The role of…

General Relativity and Quantum Cosmology · Physics 2009-02-23 K. V. S. Shiv Chaitanya , Bindu A Bambah

We use a Press-Schechter-like calculation to study how the abundance of voids changes in models with non-Gaussian initial conditions. While a positive skewness increases the cluster abundance, a negative skewness does the same for the void…

Astrophysics · Physics 2009-11-13 Marc Kamionkowski , Licia Verde , Raul Jimenez

In a variety of models the motion of the inflaton may trigger the production of some non-inflaton particles during inflation, for example via parametric resonance or a phase transition. Such models have attracted interest recently for a…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-28 Neil Barnaby

We report the observation of low-lying collective charge and spin excitations in the second Landau level at {\nu} = 2 + 1/3 and also for the very fragile states at {\nu} = 2 + 2/5, 2 + 3/8 in inelastic light scattering experiments. These…

Mesoscale and Nanoscale Physics · Physics 2015-12-16 U. Wurstbauer , A. L. Levy , A. Pinczuk , K. W. West , L. N. Pfeiffer , M. J. Manfra , G. C. Gardner , J. D. Watson

We study the evolution of cosmological perturbations on large scales, up to second order, for a perfect fluid with generic equation of state. Taking advantage of super-horizon conservation laws, it is possible to follow the evolution of the…

Astrophysics · Physics 2009-11-10 N. Bartolo , S. Matarrese , A. Riotto

We investigate recent claims that brane inflation solves the overshoot problem through a combination of microphysical restrictions on the phase space of initial conditions and the existence of the Dirac-Born-Infeld (DBI) attractor in…

High Energy Physics - Theory · Physics 2009-09-02 Simeon Bird , Hiranya V. Peiris , Daniel Baumann

We investigate the critical properties and phase structure of excited states in a holographic superconductor model within the framework of Varying Central Charge Thermodynamics, where the cosmological constant serves as a fundamental…

High Energy Physics - Theory · Physics 2026-04-28 Hoang Van Quyet

We develop a consistent analytic approach to determine the conditions under which slow roll inflation can arise when the inflaton is the same scalar field that is responsible for the bounce in Loop Quantum Cosmology (LQC). We find that the…

General Relativity and Quantum Cosmology · Physics 2019-11-04 Anshuman Bhardwaj , Edmund J. Copeland , Jorma Louko

In this paper we derive a generic expression, which is valid for scales larger than Hubble radius and contains only the local terms, for the second order curvature perturbations for more than one field, provided the expansion is sourced by…

Astrophysics · Physics 2009-11-13 Asko Jokinen , Anupam Mazumdar

Using the consistency relation in Fourier space, we derive the observed galaxy bispectrum from single-field inflation in the squeezed limit, in which one of the three modes has a wavelength much longer than the other two. This provides a…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-31 Kazuya Koyama , Obinna Umeh , Roy Maartens , Daniele Bertacca