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We consider the late time one-loop quantum backreaction from inflationary fluctuations of a non-minimally coupled, massless scalar field. The scalar is assumed to be a spectator field in an inflationary model with a constant principal slow…

General Relativity and Quantum Cosmology · Physics 2015-01-14 D. Glavan , T. Prokopec , D. van der Woude

We discuss the non-linear interactions within the VCDM model, a type II minimally modified gravity model with the same number of degrees of freedom as in General Relativity but not connected to the latter by field redefinitions. During an…

General Relativity and Quantum Cosmology · Physics 2024-07-26 Alexander Ganz , Paul Martens , Shinji Mukohyama , Ryo Namba

We examine the quantum loop effects on the single-field inflationary models in a spatially flat Friedmann-Robertson-Walker (FRW) cosmological space-time with a general self-interacting scalar field potential, which is modeled in terms of…

General Relativity and Quantum Cosmology · Physics 2020-02-05 Wei-Can Syu , Da-Shin Lee , Kin-Wang Ng

Loops of inflationary gravitons are known to induce large temporal and spatial logarithms which can cause perturbation theory to break down. Nonlinear sigma models possess the same kind of derivative interactions and induce the same sorts…

General Relativity and Quantum Cosmology · Physics 2023-09-11 C. Litos , R. P. Woodard , B. Yesilyurt

Non-Gaussianities of primordial perturbations in the soft limit provide the important information about the light degrees of freedom during inflation. The soft modes of the curvature perturbations, unobservable for a local observer, act as…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-13 Teruaki Suyama , Yuichiro Tada , Masahide Yamaguchi

Recent and upcoming experimental data as well as the possibility of rich phenomenology has spiked interest in studying the quantum gravitational effects in cosmology at low (inflation-era) energy scales. While Planck scale physics is under…

General Relativity and Quantum Cosmology · Physics 2019-05-30 Sandeep Aashish , Sukanta Panda

We present a technique, {\em the uniform asymptotic approximation}, to construct accurate analytical solutions of the linear perturbations of inflation after quantum effects of the early universe are taken into account, for which the…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-19 Tao Zhu , Anzhong Wang , Gerald Cleaver , Klaus Kirsten , Qin Sheng

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

We first derive the primordial power spectra, spectral indices and runnings of both scalar and tensor perturbations of a flat inflationary universe to the second-order approximations of the slow-roll parameters, in the framework of loop…

General Relativity and Quantum Cosmology · Physics 2016-03-25 Tao Zhu , Anzhong Wang , Klaus Kirsten , Gerald Cleaver , Qin Sheng , Qiang Wu

We consider the effects of local interactions upon quantum mechanically entangled systems. In particular we demonstrate that non-local correlations cannot increase through local operations on any of the subsystems, but that through the use…

Quantum Physics · Physics 2015-06-26 V. Vedral , M. A. Rippin , M. B. Plenio

We consider the familiar problem of a minimally coupled scalar field with quadratic potential in flat Friedmann-Lema\^itre-Robertson-Walker cosmology to illustrate a number of techniques and tools, which can be applied to a wide range of…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Artur Alho , Claes Uggla

Primordial non-Gaussianities from multi-field inflation are a leading target for cosmological observations, because of the possible large correlations generated between long and short distances. These signatures are captured by the local…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Dong-Gang Wang , Guilherme L. Pimentel , Ana Achúcarro

Our understanding of quantum correlators in cosmological spacetimes, including those that we can observe in cosmological surveys, has improved qualitatively in the past few years. Now we know many constraints that these objects must satisfy…

High Energy Physics - Theory · Physics 2022-07-27 James Bonifacio , Enrico Pajer , Dong-Gang Wang

We study slow-roll inflation driven by a scalar field non-minimally coupled to gravity within the effective framework of Loop Quantum Cosmology (LQC), including inverse-volume corrections. We consider two physically motivated classes of…

General Relativity and Quantum Cosmology · Physics 2026-03-05 Rudranil Roy , Giovanni Otalora , Joel Saavedra , Salvatore Capozziello

Recently (PRL 113, 050403 (2014)) the concept of local symmetries in one-dimensional stationary wave propagation has been shown to lead to a class of invariant two-point currents that allow to generalize the parity and Bloch theorem. In the…

Quantum Physics · Physics 2017-03-08 Peter Schmelcher , Sven Krönke , Fotis Diakonos

We consider an infrared truncated massless minimally coupled scalar field with a quartic self-interaction in the locally de Sitter background of an inflating universe. We compute the two-point correlation function of the scalar at one and…

General Relativity and Quantum Cosmology · Physics 2015-06-03 V. K. Onemli

This paper extends the calculation of quantum corrections to the cosmological correlation $<\zeta\zeta>$, which has been done by Weinberg for a loop of minimally coupled scalars, to other types of matter loops and a general and realistic…

High Energy Physics - Theory · Physics 2008-11-26 Kanokkuan Chaicherdsakul

Coupling between sub- and super-Hubble modes can affect the locally observed statistics of our universe. In the context of Quasi-Single Field Inflation, we can compute correlation functions and derive the influence of those unobservable…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Anne-Sylvie Deutsch

In the inflationary scenario of loop quantum cosmology in the presence of inverse-volume corrections, we give analytic formulas for the power spectra of scalar and tensor perturbations convenient to compare with observations. Since…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Martin Bojowald , Gianluca Calcagni , Shinji Tsujikawa

We study the generation of local non-Gaussianity in models of canonical single field inflation when their backgrounds are either attractor or non-attractor. We show that the invariance of inflation under space-time diffeomorphisms can be…

High Energy Physics - Theory · Physics 2023-04-13 Rafael Bravo , Gonzalo A. Palma