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We investigate the possibility of preheating in hybrid inflation. This scenario involves at least two scalar fields, the inflaton field $\phi$, and the symmetry breaking field $\sigma$. We found that the behavior of these fields after…

High Energy Physics - Phenomenology · Physics 2009-09-29 Juan Garcia-Bellido , Andrei Linde

The methods of effective field theory are used to study generic theories of inflation with a single inflaton field and to perform a general analysis of the associated non-Gaussianities. We investigate the amplitudes and shapes of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Nicola Bartolo , Matteo Fasiello , Sabino Matarrese , Antonio Riotto

We carry out numerical investigations of the dynamics and perturbations in the Nflation model of Dimopoulos et al. (2005). This model features large numbers of scalar fields with different masses, which can cooperate to drive inflation…

Astrophysics · Physics 2009-11-11 Soo A Kim , Andrew R Liddle

It is sometimes stated that $n_s = 0.98$ in hybrid inflation; sometimes that it predicts $n_s >1$. A number of authors have consider aspects of Planck scale corrections and argued that they affect these predictions. Here we consider these…

High Energy Physics - Phenomenology · Physics 2015-06-17 Milton Bose , Michael Dine , Angelo Monteux , Laurel Stephenson Haskins

Assuming a LCDM universe in a single-field inflationary scenario, we compute the three-point correlation function of the observed matter density fluctuation in the squeezed triangular configuration, accounting for all the relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-25 Jaiyul Yoo , Nastassia Grimm , Ermis Mitsou

Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our universe originate from quantum fluctuations, most of the established literature ignores the crucial role that…

High Energy Physics - Theory · Physics 2022-11-30 Suddhasattwa Brahma , Arjun Berera , Jaime Calderón-Figueroa

We explore the consequences of a detection of primordial tensor fluctuations for general single-field models of inflation. Using the effective theory of inflation, we propose a generalization of the Lyth bound. Our bound applies to all…

High Energy Physics - Theory · Physics 2015-06-03 Daniel Baumann , Daniel Green

Motivated by the gauge theory of gravity with local scaling symmetry proposed recently in 1712.04537 and 1506.01807, we investigate whether the scalar field therein can be responsible for the inflation. We show that the classical theory…

General Relativity and Quantum Cosmology · Physics 2018-08-07 Yong Tang , Yue-Liang Wu

Many alternatives to canonical slow-roll inflation have been proposed over the years, one of the main motivations being to have a model, capable of generating observable values of non-Gaussianity. In this work, we (re-)explore the physical…

High Energy Physics - Theory · Physics 2016-07-06 David Pirtskhalava , Luca Santoni , Enrico Trincherini

Quintessential inflation refers to scenarios in which a single scalar field is used to describe inflation and late-time acceleration. This review is dedicated to the framework of quintessential inflation, with a focus on the building blocks…

General Relativity and Quantum Cosmology · Physics 2022-04-14 Nur Jaman , M. Sami

We forecast the constraints on single-field inflation from the bispectrum of future high-redshift surveys such as MegaMapper. Considering non-local primordial non-Gaussianity (NLPNG), we find that current methods will yield constraints of…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-06 Giovanni Cabass , Mikhail M. Ivanov , Oliver H. E. Philcox , Marko Simonovic , Matias Zaldarriaga

We argue that the non-detection of primordial tensor modes has taught us a great deal about the primordial universe. In single-field slow-roll inflation, the current upper bound on the tensor-to-scalar ratio, $r < 0.07$ $(95 \% ~CL)$,…

High Energy Physics - Theory · Physics 2017-06-21 Enrico Pajer , Guilherme L. Pimentel , Jaap V. S. Van Wijck

We propose a new alternative mechanism to seed a scale invariant spectrum of primordial density perturbations that does not rely on inflation. In our scenario, a perfect fluid dominates the early stages of an expanding, non-inflating…

Astrophysics · Physics 2009-11-10 C. Armendariz-Picon , Eugene A. Lim

We discuss the coupled Einstein-Klein-Gordon equations for a complex scalar field with and without a quartic self-interaction in a zero curvature Friedman-Lema\^{\i}tre Universe. The complex scalar field, as well as the metric, is…

General Relativity and Quantum Cosmology · Physics 2011-04-15 D. Scialom

Stochastic effects in generic scenarios of inflation with multiple fields are investigated. First passage time techniques are employed to calculate the statistical moments of the number of inflationary $e$-folds, which give rise to all…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Vincent Vennin , Hooshyar Assadullahi , Hassan Firouzjahi , Mahdiyar Noorbala , David Wands

We have realized non-minimal Higgs inflation and standard hybrid inflation in the supersymmetric flipped $SU(5)$ model with $U(1)_R$ symmetry using the no-scale form of the K\"{a}hler potential. In non-minimal Higgs inflation the waterfall…

High Energy Physics - Phenomenology · Physics 2021-10-12 Mian Muhammad Azeem Abid , Maria Mehmood , Mansoor Ur Rehman , Qaisar Shafi

We study the possibility that inflation is driven by a scalar field together with a vector field minimally coupled to gravity. By assuming an effective potential that incorporates both fields into the action, we explore two distinct…

General Relativity and Quantum Cosmology · Physics 2024-12-09 Manuel Gonzalez-Espinoza , Ramon Herrera

We introduce a frame-covariant formalism for inflation of scalar-curvature theories by adopting a differential geometric approach which treats the scalar fields as coordinates living on a field-space manifold. This ensures that our…

High Energy Physics - Phenomenology · Physics 2018-01-09 Sotirios Karamitsos , Apostolos Pilaftsis

It is shown in this letter that in the framework of an inhomogeneous geometry and a massive non self-interacting scalar field with spherical symmetry, one needs a homogeneous patch bigger than a dizaine of horizons in order to start…

General Relativity and Quantum Cosmology · Physics 2012-05-18 R. S. Perez , N. Pinto-Neto

We study inflation in models with many interacting fields subject to randomly generated scalar potentials. We use methods from non-equilibrium random matrix theory to construct the potentials and an adaption of the 'transport method' to…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-07 Mafalda Dias , Jonathan Frazer , M. C. David Marsh