English
Related papers

Related papers: Observational Exclusion of a Consistent Quantum Co…

200 papers

By incorporating quantum aspects of gravity, Loop Quantum Cosmology (LQC) provides a self-consistent extension of the inflationary scenario, allowing for modifications in the primordial inflationary power spectrum with respect to the…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-01 Micol Benetti , Leila Graef , Rudnei O. Ramos

Recently the mechanism was found which allows avoidance of the cosmological singularity within the semi-classical formulation of Loop Quantum Gravity. Numerical studies show that the presence of self-interaction potential of the scalar…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. V. Vereshchagin

Quantum effects play an essential role in modern cosmology. Perhaps the most striking example comes from large-scale structures, generally assumed to originate from vacuum quantum fluctuations and stretched by an expansion phase. Inflation…

General Relativity and Quantum Cosmology · Physics 2020-10-08 Emmanuel Frion

The Planck collaboration has provided us rich information about the early universe, and a host of new observational missions will soon shed further light on the `anomalies' that appear to exist on the largest angular scales. From a quantum…

General Relativity and Quantum Cosmology · Physics 2015-11-18 Abhay Ashtekar , Aurelien Barrau

A simple inflationary model based on loop quantum cosmology is considered. Within this framework, we show that inflation does not necessarily erase the infor- mation prior to its onset, but that such information may leave its imprint in the…

General Relativity and Quantum Cosmology · Physics 2010-05-21 Carlos Marques Afonso , Alfredo Barbosa Henriques , Paulo Vargas Moniz

Cosmological inflation is the dominating paradigm to account for observations of the Cosmic Microwave Background (CMB). In this thesis, we study the phenomenology of a class of particularly well motivated models of inflation, known under…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-27 Stefano Orani

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

The primordial Universe can be used as a laboratory to set constraints on quantum gravity. In the framework of Loop Quantum Cosmology, we show that such a proposal for quantum gravity not only solves for the big bang singularity issue but…

General Relativity and Quantum Cosmology · Physics 2012-06-08 Julien Grain

Inflation in the early Universe is one of the most promising probes of gravity in the high-energy regime. However, observable scales give access to a limited window in the inflationary dynamics. In this essay, we argue that quantum…

High Energy Physics - Theory · Physics 2017-11-22 Robert J. Hardwick , Vincent Vennin , David Wands

Since inflationary perturbations must generically couple to all degrees of freedom present in the early Universe, it is more realistic to view these fluctuations as an open quantum system interacting with an environment. Then, on very…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-10 Jerome Martin , Vincent Vennin

We investigate the pre-inflationary dynamics of inflation with the Starobinsky potential, favored by recent data from the Planck mission, using techniques developed to study cosmological perturbations on quantum spacetimes in the framework…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Béatrice Bonga , Brajesh Gupt

In loop quantum cosmology, the universe avoids a big bang singularity and undergoes an early and short super-inflation phase. During super-inflation, non-perturbative quantum corrections to the dynamics drive an inflaton field up its…

Astrophysics · Physics 2011-02-23 Shinji Tsujikawa , Parampreet Singh , Roy Maartens

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

The conventional $\Lambda$CDM cosmological model supplemented by the inflation concept describes the Universe very well. However, there are still a few concerns: new Planck data impose constraints on the shape of the inflaton potential,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-03 Branislav Vlahovic , Maxim Eingorn , Cosmin Ilie

We calculate the full spectrum, as observed today, of the cosmological gravitational waves generated within a model based on loop quantum cosmology. It is assumed that the universe, after the transition to the classical regime, undergoes a…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Paulo M. Sá , Alfredo B. Henriques

The 2015 Planck data release tightened the region of the allowed inflationary models. Inflationary models with convex potentials have now been ruled out since they produce a large tensor to scalar ratio. Meanwhile the same data offers…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Eleonora Di Valentino , Laura Mersini-Houghton

In a previous paper we proposed a new approach to the beginning of inflation -- a lingering universe. The universe begins in a lingering state with a nearly vanishing Hubble parameter. This calls into question the absolute age of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-09 Brandon Melcher , Arnab Pradhan , Scott Watson

The era of precision cosmology has allowed us to accurately determine many important cosmological parameters, in particular via the CMB. Confronting Loop Quantum Cosmology with these observations provides us with a powerful test of the…

General Relativity and Quantum Cosmology · Physics 2012-04-06 Ivan Agullo , Abhay Ashtekar , William Nelson

Possibly, the most general action in the background of isotropic and homogeneous space-time has been considered to study the quantum evolution of the early universe, apart from a cosmological constant. The hermiticity of the effective…

High Energy Physics - Theory · Physics 2020-10-30 Ranajit Mandal , Dalia Saha , Mohosin Alam , Abhik Kumar Sanyal

Informed by a quantum information perspective, we interpret cosmological expansion of space as growing entanglement between underlying degrees of freedom. In particular, we focus on inflationary cosmology, which, while being a successful…

General Physics · Physics 2021-09-10 Ashmeet Singh , Olivier Doré