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Related papers: Constraining Inflation Models with Spinning Voids

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We perform a model-independent analysis of kinetically driven inflation (KDI) which (partially) includes Generalized G-inflation and Ghost inflation. We evaluate the background evolution splitting into the inflationary attractor and the…

High Energy Physics - Theory · Physics 2018-04-25 Rio Saitou

We show that dissipative effects have a significant impact on the evolution of cosmological scalar fields, leading to friction, entropy production and field fluctuations. We explicitly compute the dissipation coefficient for different…

High Energy Physics - Phenomenology · Physics 2015-05-06 Sam Bartrum , Arjun Berera , Joao G. Rosa

Inflation is a necessary cosmic mechanism to cure basic inconsistencies of the standard model of cosmology. These problems are usually `fixed' by postulating the existence of a scalar field (called the ``inflaton''). However, other less ad…

General Relativity and Quantum Cosmology · Physics 2026-01-16 Joan Solà Peracaula , Àlex González-Fuentes , Cristian Moreno-Pulido

Primordial non-Gaussianities from multi-field inflation are a leading target for cosmological observations, because of the possible large correlations generated between long and short distances. These signatures are captured by the local…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Dong-Gang Wang , Guilherme L. Pimentel , Ana Achúcarro

The distribution of spin direction of ~6.4*10^4 spiral galaxies with spectra was examined. The analysis shows a statistically significant cosmological-scale asymmetry between galaxies with opposite spin direction. The data also reveals that…

Astrophysics of Galaxies · Physics 2019-12-18 Lior Shamir

The ability to test and constrain theories of cosmic inflation will advance substantially over the next decade. Key data sources include cosmic microwave background (CMB) measurements and observations of the distribution of matter at…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-13 Benedict Bahr-Kalus , David Parkinson , Richard Easther

We calculate the bispectrum of the gravitational field fluctuations generated during warm inflation, where dissipation of the vacuum potential during inflation is the mechanism for structure formation. The bispectrum is non--zero because of…

Astrophysics · Physics 2011-05-10 S. Gupta , A. Berera , A. F. Heavens , S. Matarrese

Why is non-Gaussianity interesting? One of generic predictions from inflationary scenarios is that primordial fluctuations are exactly Gaussian in linear order; however, the non-linearity in the inflation will produce weak non-Gaussianity.…

Astrophysics · Physics 2017-08-23 Eiichiro Komatsu , David N. Spergel

Inflation universally produces classical almost scale free Gaussian inhomogeneities of any light scalars. Assuming the coupling constants at the time of inflation depend on some light moduli fields, we encounter the generation of modulated…

Astrophysics · Physics 2009-11-10 Francis Bernardeau , Lev Kofman , Jean-Philippe Uzan

In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…

High Energy Physics - Theory · Physics 2008-11-26 Jerome Martin , Robert H. Brandenberger

We present a simple method for evaluating the nonlinear biasing function of galaxies from a redshift survey. The nonlinear biasing is characterized by the conditional mean of the galaxy density fluctuation given the underlying mass density…

Astrophysics · Physics 2009-10-31 Yair Sigad , Enzo Branchini , Avishai Dekel

In this dissertation, we introduce a general way of modeling inflation in a framework that is independent of the exact nature of the inflationary potential. Because of the choice of our initial conditions and the continuity of the scale…

High Energy Physics - Theory · Physics 2009-05-19 Matthew M. Glenz

Massive spinning particles, if present during inflation, lead to a distinctive bispectrum of primordial perturbations, the shape and amplitude of which depend on the masses and spins of the extra particles. This signal, in turn, leaves an…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-16 Azadeh Moradinezhad Dizgah , Hayden Lee , Julian B. Muñoz , Cora Dvorkin

We obtain cosmological constraints on models of inflation which exhibit rapid roll solutions. Rapid roll attractors exist for potentials with large mass terms and are thus of interest for inflationary model building within string theory. We…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-15 Takeshi Kobayashi , Shinji Mukohyama , Brian A. Powell

We study the realization of cosmic inflation in bigravity theories. By analyzing the evolution of scalar, vector, and tensor perturbations in de Sitter-like spacetimes, we find strong stability constraints on the class of viable vacua…

High Energy Physics - Theory · Physics 2012-12-21 Vicente Atal , Luis E. Campusano , Gonzalo A. Palma

Smooth hybrid inflation is a hybrid inflation model which is free from topological defects and predicts the density perturbation with the spectral index of about $0.97$. We show that the prediction on the spectral index is robust regardless…

High Energy Physics - Phenomenology · Physics 2025-10-28 Nobuchika Okada , Osamu Seto

We introduce a set of generic conditions for the slow contracting Universe and for a narrowed-down category of models called fast-roll models. We present general conditions for super horizon freeze-out of scalar and tensor perturbations and…

General Relativity and Quantum Cosmology · Physics 2021-08-23 Michał Artymowski , Ido Ben-Dayan , Udaykrishna Thattarampilly

This paper investigates a scale-invariant inflationary model characterized by a scalar field non-minimally coupled to gravity and a curvature term quadratic in the Ricci scalar. The model's dynamic is analyzed using a full numerical…

High Energy Physics - Theory · Physics 2024-10-10 Mariaveronica De Angelis , Chiara Cecchini , Massimiliano Rinaldi

Standard inflationary models yield a characteristic signature of a primordial power spectrum with a red tensor and scalar tilt. Nevertheless, Cannone et al recently suggested that, by breaking the assumption of spatial diffeomorphism…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-20 Leila Graef , Robert Brandenberger

The generic prediction for the perturbations generated during slow--roll, single--field inflation, as they appear in the cosmic microwave background (CMB), is a flat, close--to--Gaussian spectrum. We calculate the general solution for a…

Astrophysics · Physics 2007-05-23 S. Gupta