Related papers: Inflation vs. Ekpyrosis -- comparing stability in …
We propose a minimal extension of the standard model of particle physics to accommodate cosmic inflation, dark matter and light neutrino masses. While the inflationary phase is obtained from a modified chaotic inflation scenario, consistent…
A new Lagrangian framework has recently been proposed to describe interactions between relativistic perfect fluids and scalar fields. In this paper we investigate the Einstein static universe in this new class of theories, which have been…
We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…
Loop quantum cosmology with a scalar field is known to be closely linked with an inflationary phase. In this article, we study probabilistic predictions for the duration of slow-roll inflation, by assuming a minimalist massive scalar field…
In the framework of geometrothermodynamics, we explore how to construct an inflationary cosmic fluid without requiring inflaton fields. To do so, we employ standard radiation and matter as barotropic background, speculating on the existence…
The homogeneous cosmological model in GR is proposed, where the vacuum energy, which can cause the inflation, is described by tensor field rather than by commonly used in inflationary scenarios scalar field. It is shown that if the initial…
Space-based missions studying the cosmic microwave background (CMB) have progressively refined the parameter space in conventional models of inflation shortly ($\sim 10^{-37}$ seconds) after the big bang. While most inflationary scenarios…
New Ekpyrotic Cosmology is an alternative scenario of the early universe which relies on a phase of slow contraction before the big bang. We calculate the 3-point and 4-point correlation functions of primordial density perturbations and…
The purpose of these lectures is to give a pedagogical introduction to inflation and the production of primordial perturbations, as well as a review of some of the latest developments in this domain. After a short introduction, we review…
The results from Planck2015, when combined with earlier observations from WMAP, ACT, SPT and other experiments, were the first observations to disfavor the "classic" inflationary paradigm. To satisfy the observational constraints,…
The shortcomings of the Standard Big Bang Cosmological Model as well as their resolution in the context of inflationary cosmology are discussed. The inflationary scenario and the subsequent oscillation and decay of the inflaton field are…
The usual theory of inflation breaks down in eternal inflation. We derive a dual description of eternal inflation in terms of a deformed Euclidean CFT located at the threshold of eternal inflation. The partition function gives the amplitude…
The large-scale structure of the universe suggests that the physics underlying its early evolution is scale-free. This was the historic motivation for the Harrison-Zel'dovich-Peebles spectrum and for inflation. Based on a hydrodynamical…
In the primordial universe, fields with mass much larger than the mass-scale of the event-horizon (such as the Hubble parameter in inflation) exist ubiquitously, and can be excited from time to time and oscillate quickly around their…
We study particle creation in the presence of bulk viscosity of cosmic fluid in the early universe within the framework of open thermodynamical systems. Since the first-order theory of non-equilibrium thermodynamics is non-causal and…
Understanding the behavior of the universe at large depends critically on insights about the smallest units of matter and their fundamental interactions. Inflationary cosmology is a highly successful framework for exploring these…
We consider the eternal inflation scenario of the slow-roll/chaotic type with the additional element of an objective collapse of the wave function. The incorporation of this new agent to the traditional inflationary setting might represent…
We provide exact solutions to the Einstein equations when the Universe contains vacuum energy plus a uniform arrangements of magnetic fields, strings, or domain walls. Such a universe has planar symmetry, i. e., it is homogeneous but, not…
The pre-big-bang cosmology inspired by superstring theories has been suggested as an alternative to slow-roll inflation. We analyze, in both the Jordan and Einstein frames, the effect of spatial curvature on this scenario and show that too…
Models of cosmic inflation suggest that our universe underwent an early phase of accelerated expansion, driven by the dynamics of one or more scalar fields. Inflationary models make specific, quantitative predictions for several observable…