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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

The main objective of this study is to investigate the phenomenon of the bouncing scenario of the universe. The most widely recognized cosmological framework is the standard cosmological model, sometimes referred to as the Big Bang model.…

General Relativity and Quantum Cosmology · Physics 2024-02-13 A. S. Agrawal

An overview of baryogenesis in the early Universe is presented. The standard big bang model including big bang nucleosynthesis and inflation is breifly reviewed. Three basic models for baryogenesis will be developed: The ``standard"…

High Energy Physics - Phenomenology · Physics 2015-06-25 Keith A. Olive

I study a model which describes the birth of the universe using a global topological phase transition with a complex manifold where the time, $\tau$, is considered as a complex variable. Before the big bang $\tau$ is a purely imaginary…

General Relativity and Quantum Cosmology · Physics 2017-05-24 Mauricio Bellini

We perform a semi-classical analysis of the Emergent Universe scenario for inflation. Fixing the background, and taking the inflaton to be homogenous, we cast the inflaton's evolution as a one-dimensional quantum mechanics problem. We find…

High Energy Physics - Theory · Physics 2013-11-20 Anthony Aguirre , John Kehayias

Inflation provides a natural mechanism to account for the origin of cosmic structures. The generation of primordial inhomogeneities during inflation can be understood via the spontaneous creation of quanta from the vacuum. We show that when…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ivan Agullo , Leonard Parker

These notes form an introduction to cosmology with special emphasis on large scale structure, the cmb anisotropy and inflation. In some places a basic familiarity with particle physics is assumed, but otherwise no special knowledge is…

Astrophysics · Physics 2007-05-23 David H Lyth

Inflationary models, especially those with plateau-type potentials, are consistent with the cosmological data, but inflation itself does not resolve the initial singularity. This singularity is resolved, for example, by the idea of the…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Hiroki Matsui , Alexandros Papageorgiou , Fuminobu Takahashi , Takahiro Terada

Progress in early Universe cosmology, including strings, extra dimensions, inflation, phase transitions, and baryogenesis, is reviewed.

High Energy Physics - Phenomenology · Physics 2007-05-23 Keith A. Olive

Cosmological inflation and topological defects have been considered for a long time, either in disagreement or in competition. On the one hand an inflationary era is required to solve the shortcomings of the hot big bang model, while on the…

High Energy Physics - Theory · Physics 2008-11-26 Mairi Sakellariadou

The equations that govern the dynamics of the universe in the modified unimodular theory of gravity are derived. We find a mechanism for inflation in the early universe without postulating a false vacuum state during the first $10^{-35}$…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Robert D. Bock

We show that in a generic case of the pre-big-bang scenario, inflation will solve cosmological problems only if the universe at the onset of inflation is extremely large and homogeneous from the very beginning. The size of a homogeneous…

High Energy Physics - Theory · Physics 2009-09-29 Nemanja Kaloper , Andrei Linde , Raphael Bousso

We analyse numerically the onset of pre-big bang inflation in an inhomogeneous, spherically symmetric Universe. Adding a small dilatonic perturbation to a trivial (Milne) background, we find that suitable regions of space undergo…

General Relativity and Quantum Cosmology · Physics 2010-02-03 J. Maharana , E. Onofri , G. Veneziano

The origins of matter and radiation in the universe lie in a Hot Big Bang. We present a number of well-motivated cosmologies in which the Big Bang occurs through a strong first order phase transition -- either at the end of inflation, after…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-30 Katherine Freese , Martin Wolfgang Winkler

We discuss the interaction between perturbations in the inflaton and the background during the preheating phase in simple inflationary models. By numerically solving the Einstein field equations we are able to assess the impact of…

High Energy Physics - Phenomenology · Physics 2009-10-31 Richard Easther , Matthew Parry

In the present work we discuss inflation, dark matter and cosmological evolution in the context of the brane-world scenario. Being string theory inspired, the brane-world models provide corrections to the General Relativity, which is…

High Energy Physics - Phenomenology · Physics 2012-05-28 G. Panotopoulos

We describe the universe as a local, inhomogeneous spherical bubble embedded in a flat matter dominated FLRW universe. Generalized exact Friedmann equations describe the expansion of the universe and an early universe inflationary de Sitter…

Astrophysics · Physics 2007-05-23 J. W. Moffat

The physical basis of the modern cosmological inflationary models with baryosynthesis and nonbaryonic dark matter and energy implies such predictions of particle theory, that, in turn, apply to cosmology for their test. It makes physics of…

Astrophysics · Physics 2007-05-23 Maxim Yu. Khlopov

We discuss early cosmology in theories where the fundamental Planck mass is close to the TeV scale. In such theories the standard model fields are localized to a (3+1)-dimensional wall with n new transverse sub-millimeter sized spatial…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nima Arkani-Hamed , Savas Dimopoulos , Nemanja Kaloper , John March-Russell

It is commonly believed that our Universe has experienced two different stages of accelerated expansion. The early stage is known as inflation and the current acceleration is driven by dark energy. Observing inflation and dark energy…

Astrophysics · Physics 2009-11-11 Jun-Qing Xia , Gong-Bo Zhao , Bo Feng , Xinmin Zhang