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Cosmological inflation is studied in the case where the inflaton is the overall modulus $T$ for an orbifold. General forms of the (non-perturbative) superpotential are considered to ensure that $G=K+{\rm ln}|W|^2$ is modular invariant. We…

High Energy Physics - Theory · Physics 2009-10-31 D. Bailin , G. V. Kraniotis , A. Love

Motivated by the work of Nojiri et al. (2019) [S. Nojiri, S. D. Odintsov and E. N. Saridakis, Holographic inflation, Phys. Lett. B 797 (2019) 134829], the present study reports a model of inflation under the consideration that the…

General Physics · Physics 2020-06-15 Gargee Chakraborty , Surajit Chattopadhyay

We explore inflationary cosmology in a theory where there are two scalar fields which non-minimally couple to the Ricci scalar and an additional $R^2$ term, which breaks the conformal invariance. Particularly, we investigate the slow-roll…

High Energy Physics - Theory · Physics 2015-07-10 Kazuharu Bamba , Sergei D. Odintsov , Petr V. Tretyakov

A variant of hybrid inflation which is applicable in a wide class of supersymmetric grand unified models and reproduces the observed temperature perturbations of cosmic background radiation with natural values of the parameters is…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Lazarides

A unified description of inflation, dark energy, and dark matter is presented within a two-scalar-field cosmological model. Inflation, assumed to be of the warm type, is driven by one of the scalar fields, which, shortly after the end of…

General Relativity and Quantum Cosmology · Physics 2020-11-24 Paulo M. Sá

We discuss relationship between inflation and various models of production of density inhomogeneities due to strings, global monopoles, textures and other topological and non-topological defects. Neither of these models leads to a…

High Energy Physics - Phenomenology · Physics 2009-09-29 Andrei Linde

The dynamics of hybrid models is usually approximated by the evolution of a scalar field slowly rolling along a nearly flat valley. Inflation ends with a waterfall phase, due to a tachyonic instability. This final phase is usually assumed…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-27 Sébastien Clesse

We propose a new scenario for early cosmology, where an inflationary de Sitter phase is obtained with a ghost condensate. The transition to radiation dominance is triggered by the ghost itself, without any slow-roll potential. Density…

High Energy Physics - Theory · Physics 2011-05-05 Nima Arkani-Hamed , Paolo Creminelli , Shinji Mukohyama , Matias Zaldarriaga

In the hope of avoiding model dependence of the cosmological observables, phenomenological parametrizations of Cosmic Inflation have recently been proposed. Typically, they are expressed in terms of two parameters associated with an…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-16 Jerome Martin , Christophe Ringeval , Vincent Vennin

We propose a model for cosmic inflation which is based on an effective description of strongly interacting, nonsupersymmetric matter within the framework of dynamical abelian projection and centerization. The underlying gauge symmetry is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ralf Hofmann , Mathias Th. Keil

We consider cosmological inflation generated by a scalar field slowly rolling off from a de Sitter maximum of its potential. The models belong to the class of hilltop models and represent the most general model of this kind in which the…

General Relativity and Quantum Cosmology · Physics 2016-09-05 Mariano Cadoni , Edgardo Franzin , Salvatore Mignemi

Using the techniques of out-of-equilibrium field theory, we study the influence on the properties of cosmological perturbations generated during inflation on observable scales coming from fluctuations corresponding today to scales much…

High Energy Physics - Theory · Physics 2009-11-10 Sabino Matarrese , Marcello A. Musso , Antonio Riotto

An intermediate inflationary universe model within the context of non-minimally coupled to the scalar curvature is analyzed. We will conduct our analysis under the slow roll approximation of the inflationary dynamics and the cosmological…

General Relativity and Quantum Cosmology · Physics 2017-09-12 Carlos Gonzalez , Ramon Herrera

We propose a new class of inflationary solutions to the standard cosmological problems (horizon, flatness, monopole,...), based on a modification of old inflation. These models do not require a potential which satisfies the normal…

High Energy Physics - Theory · Physics 2007-05-23 Gia Dvali , Shamit Kachru

We investigate thermal inflation in double-screen entropic cosmology. We find that its realization is general, resulting from the system evolution from non-equilibrium to equilibrium. Furthermore, going beyond the background evolution, we…

High Energy Physics - Theory · Physics 2011-05-26 Yi-Fu Cai , Emmanuel N. Saridakis

We study the behaviour of inflationary density perturbations in the vicinity of horizon crossing, using numerical evolution of the relevant mode equations. We explore two specific scenarios. In one, inflation is temporarily ended because a…

Astrophysics · Physics 2009-10-31 Samuel M Leach , Andrew R Liddle

The very basics of cosmological inflation are discussed. We derive the equations of motion for the inflaton field, introduce the slow-roll parameters, and present the computation of the inflationary perturbations and their connection to the…

General Relativity and Quantum Cosmology · Physics 2012-01-31 K. Enqvist

We investigated the formation and evolution of CDM subhalos in galaxy-sized and cluster-sized halos by means of N-body simulations. Our aim is to make clear what the ``dwarf galaxy problem'' is. It has been argued that the number of…

Astrophysics · Physics 2015-06-24 Hiroyuki Kase , Junichiro Makino , Yoko Funato

We develop a general formalism for analyzing linear perturbations in multiple-field cosmological inflation based on the gauge-ready approach. Our inflationary model consists of an arbitrary number of scalar fields with non-minimal kinetic…

Astrophysics · Physics 2009-11-13 Joydev Lahiri , Gautam Bhattacharya

Thermal inflation models (which feature two inflationary stages) can display damped primordial curvature power spectra on small scales which generate damped matter fluctuations. For a reasonable choice of parameters, thermal inflation…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-11 Matteo Leo , Carlton M. Baugh , Baojiu Li , Silvia Pascoli