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In string theory, even when there are ten to the thousand power vacuum states, does inflation produce overwhelmingly one preferred type of vacuum state? We respond affirmatively to questions whether existence of graviton production is…

General Physics · Physics 2014-11-18 A. W. Beckwith

We review some perturbative results obtained in quantum gravity in an accelerating cosmological background. We then describe a class of non-local, purely gravitational models which have the correct structure to reproduce the leading…

General Relativity and Quantum Cosmology · Physics 2015-06-04 M. G. Romania , N. C. Tsamis , R. P. Woodard

Quantum gravitational back-reaction offers the potential of simultaneously resolving the problem of the cosmological constant and providing a natural model of inflation in which scalars play no special role. In this model inflation begins…

Astrophysics · Physics 2007-05-23 R. P. Woodard

We present a way to accomodate relic graviton production via worm hole transitions of prior universe thermal / energy density values to our present universe. This is done in the context of providing a mechanism for thermally driven relic…

General Physics · Physics 2008-11-07 A. W. Beckwith

The quantum gravitational back-reaction on inflation is based on the self-gravitation of infrared gravitons which are ripped out of the vacuum during inflation. The only quantum part of this process is the creation of gravitons; after they…

General Relativity and Quantum Cosmology · Physics 2022-04-20 N. C. Tsamis , R. P. Woodard

Cosmological inflation remains a key paradigm for explaining the earliest stages of the Universe, yet the theoretical limitations of General Relativity (GR) motivate the development of alternative formulations capable of addressing both…

General Relativity and Quantum Cosmology · Physics 2025-11-13 Maryam Shiravand , Saeed Fakhry , Javad T. Firouzjaee , Ali Tizfahm

Recent cosmic microwave background observations favor low energy scale inflationary models in a closed universe. However, onset of inflation in such models for a closed universe is known to be severely problematic. In particular, such a…

General Relativity and Quantum Cosmology · Physics 2021-03-03 Lucia Gordon , Bao-Fei Li , Parampreet Singh

We propose a model of inflation in the framework of brane cosmology driven by background supergravity. Starting from bulk supergravity we construct the inflaton potential on the brane and employ it to investigate for the consequences to…

High Energy Physics - Theory · Physics 2012-12-21 Sayantan Choudhury , Supratik Pal

A cubic correction of $f(T)$ gravity, where $T$ is the teleparallel scalar torsion, is considered to describe gravity in spatially flat Friedmann-Robertson-Walker model. A scale factor permitting departure from inflation era has been…

General Physics · Physics 2015-11-06 G. G. L. Nashed , W. El Hanafy

We propose a method to extract predictions from quantum cosmology for inflation that can be confronted with observations. Employing the tunneling boundary condition in quantum geometrodynamics, we derive a probability distribution for the…

General Relativity and Quantum Cosmology · Physics 2015-07-21 Gianluca Calcagni , Claus Kiefer , Christian F. Steinwachs

We investigate cosmological solutions for the modified gravity theory obtained from quantum relative entropy between the metric of spacetime and the metric induced by the geometry and matter fields. The vacuum equations admit inflationary…

General Relativity and Quantum Cosmology · Physics 2025-12-23 Udaykrishna Thattarampilly , Yunlong Zheng

Recent debates around the testability of the inflationary paradigm raise the question of how to model-independently discriminate it from competing scenarios. We argue that a detection of the Cosmic Graviton Background (CGB), the relic…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-04 Sunny Vagnozzi , Abraham Loeb

A huge value of cosmological constant characteristic for the particle physics and the inflation of early Universe are inherently related to each other: one can construct a fine-tuned superpotential, which produces a flat potential of…

General Relativity and Quantum Cosmology · Physics 2015-06-03 V. V. Kiselev , S. A. Timofeev

Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from…

High Energy Physics - Phenomenology · Physics 2023-06-23 Arjun Berera

A continuous process of creation of particles is investigated as a possible connection between the inflationary stage with late cosmic acceleration. In this model, the inflationary era occurs due to a continuous and fast process of creation…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Rafael C. Nunes

A brief review of the modern state of quantum cosmology is presented as a theory of quantum initial conditions for inflationary scenario. The no-boundary and tunneling states of the Universe are discussed as a possible source of probability…

General Relativity and Quantum Cosmology · Physics 2017-08-23 A. O. Barvinsky

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 2009-11-07 Ralf Hofmann , Mathias Th. Keil

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

Cosmic Inflation provides an attractive framework for understanding the early universe and the cosmic microwave background. It can readily involve energies close to the scale at which Quantum Gravity effects become important. General…

High Energy Physics - Theory · Physics 2015-04-22 Anton de la Fuente , Prashant Saraswat , Raman Sundrum

This review article aims at presenting the theory of inflation. We first describe the background spacetime behavior during the slow-roll phase and analyze how inflation ends and the Universe reheats. Then, we present the theory of…

High Energy Physics - Theory · Physics 2009-11-10 Jerome Martin
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