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Related papers: Current Issues for Inflation

200 papers

We revisit the F-term hybrid inflation model in supergravity. In particular, we point out that a constant term in the superpotential has significant effects on the inflaton dynamics. It is shown that the hybrid inflation model suffers from…

High Energy Physics - Phenomenology · Physics 2011-04-15 Kazunori Nakayama , Fuminobu Takahashi , Tsutomu T. Yanagida

In this paper, we investigate D-term inflation within the framework of supergravity, employing the minimal K\"{a}hler potential. Following previous studies that revealed that this model can overcome the $\eta$-problem found in F-term…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-02 K. El Bourakadi , G. Otalora , A. Burton-Villalobos , H. Chakir , M. Ferricha-Alami , M. Bennai

A gravity-driven inflation is shown to arise from a simple higher dimensional universe. In vacuum, the shear of $n>1$ contracting dimensions is able to inflate the remaining three spatial dimensions. Said another way, the expansion of the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Janna Levin

Thermal history after inflation is studied in a chaotic inflation model with supersymmetric couplings of the inflaton to matter fields. Time evolution equation is solved in a formalism that incorporates both the back reaction of particle…

High Energy Physics - Phenomenology · Physics 2014-11-17 H. Fujisaki , K. Kumekawa , M. Yamaguchi , M. Yoshimura

This contribution to the proceedings collects new recent results on preheating after inflation. We discuss tachyonic preheating in the SUSY motivated hybrid inflation; development of equilibrium after preheating; theory of fermionic…

High Energy Physics - Phenomenology · Physics 2007-05-23 Lev Kofman

We study a recently proposed running kinetic inflation model in which the inflaton potential becomes flat due to rapid growth of the kinetic term at large inflaton field values. As concrete examples, we build a variety of chaotic inflation…

High Energy Physics - Phenomenology · Physics 2010-12-09 Kazunori Nakayama , Fuminobu Takahashi

The idea of gravity as an "emergent" phenomenon has gained popularity in recent years. I discuss some of the obstacles that any such model must overcome in order to agree with the observational underpinnings of general relativity.

General Relativity and Quantum Cosmology · Physics 2012-07-23 S. Carlip

Present data require a spectral index $n\gsim 0.95$ at something like 1-$\sigma$ level. If this lower bound survives it will constrain `new' and `modular' inflation models, while raising it to 1.00 would rule out all of these models plus…

High Energy Physics - Phenomenology · Physics 2007-05-23 David H. Lyth

We consider an inflationary model in the hidden-sector broken supergravity with an effectively large cutoff. The inflaton decay into right-handed neutrinos naturally causes the observed baryon asymmetry of the universe with a reheating…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Ibe , K. -I. Izawa , Y. Shinbara , T. T. Yanagida

The warm inflation paradigm considers the continuous production of radiation during inflation due to dissipative effects. In its strong dissipation limit, warm inflation gives way to a radiation dominated Universe. High scale inflation then…

High Energy Physics - Phenomenology · Physics 2011-03-18 Juan C. Bueno Sanchez , Mar Bastero-Gil , Arjun Berera , Konstantinos Dimopoulos , Kazunori Kohri

In supersymmetric models of warm inflation, the large temperature of the radiation bath produced by the dissipative motion of the inflaton field may induce a significant thermal abundance of potentially dangerous gravitinos. While previous…

High Energy Physics - Phenomenology · Physics 2013-01-16 Sam Bartrum , Arjun Berera , Joao G. Rosa

Gravitino production in the primordial Universe is investigated into details. After briefly reviewing inflation, supersymmetry and supergravity, we first study the scattering of massive W bosons in the thermal bath of particles, during the…

High Energy Physics - Phenomenology · Physics 2018-02-27 Andrea Ferrantelli

We use the Bogoliubov formalism to study both, particles and gravitons creation at the reheating epoch, after a phase transition from inflation to a radiation dominated universe. The modes of the inflaton field fluctuations and the scalar…

General Relativity and Quantum Cosmology · Physics 2011-10-07 Mariano Anabitarte , Mauricio Bellini

In these lectures, after a short introduction to cosmology, we discuss the supergravity embedding of higher curvature models of inflation. The supergravity description of such models is presented for the two different formulations of…

High Energy Physics - Theory · Physics 2014-10-23 Sergio Ferrara , Alex Kehagias

A Gauss-Bonnet term naturally appears in the action for gravity when one considers the existence of space time with dimensions more than 1+3. A variety of inflationary models can be obtained within such a framework, once the scale factor…

General Relativity and Quantum Cosmology · Physics 2013-02-19 Isha Pahwa , Debajyoti Choudhury , T. R. Seshadri

An overview of some new results in open inflation over the past year, including the calculation of gravity wave contributions to the Cosmic Microwave Background. Proceedings for COSMO-97, held in Ambleside, U.K., hence very short due to…

Astrophysics · Physics 2016-10-26 J. D. Cohn

A popular science article designed to introduce people familiar with basic cosmological nomenclature with models alternative to cosmological inflation. The paper briefly discusses the modern view of the Big Bang model, inflation (both its…

Popular Physics · Physics 2024-04-30 Marcin Postolak

The notion of inflation (past or present) in standard cosmological models is shown to be a consequence of a sufficiently high second law entropy production from the internal heating of the universal expansion. The longitudinal viscous…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. Sakai , A. Widom , Y. N. Srivastava

We study the consequences of the gravitino decay into dark matter. We suppose that the lightest neutralino is the main component of dark matter. In our framework gravitino is heavy enough to decay before Big Bang Nucleosynthesis starts. We…

High Energy Physics - Phenomenology · Physics 2007-06-29 David Gherson

These lecture notes intend to form a short pedagogical introduction to inflationary cosmology, highlighting selected areas of recent progress such as reheating and the theory of cosmological perturbations. Problems of principle for…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robert H. Brandenberger