J 2021

Scale-invariant quadratic gravity and inflation in the Palatini formalism

GIALAMAS, Ioannis D., Alexandros KARAM, Thomas PAPPAS and Vassilis C. SPANOS

Basic information

Original name

Scale-invariant quadratic gravity and inflation in the Palatini formalism

Authors

GIALAMAS, Ioannis D., Alexandros KARAM, Thomas PAPPAS (300 Greece, belonging to the institution) and Vassilis C. SPANOS

Edition

Physical Review D, College Park (USA), American Physical Society, 2021, 2470-0010

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

RIV identification code

RIV/47813059:19630/21:A0000116

Organization unit

Institute of physics in Opava

DOI

http://dx.doi.org/10.1103/PhysRevD.104.023521

UT WoS

000675556000001

Keywords in English

DARK-MATTER;SYMMETRY-BREAKING;HIGGS;FLATNESS;UNIVERSE;HORIZON;MODELS

Tags

2022, , GA19-03950S, RIV22

Tags

International impact, Reviewed

Links

GA19-03950S, research and development project.
Změněno: 23/2/2022 12:58, Mgr. Pavlína Jalůvková

Abstract

V originále

In the framework of classical scale invariance, we consider quadratic gravity in the Palatini formalism and investigate the inflationary predictions of the theory. Our model corresponds to a two-field scalar-tensor theory, which involves the Higgs field and an extra scalar field stemming from a gauge U(1)(X) extension of the Standard Model, which contains an extra gauge boson and three right-handed neutrinos. Both scalar fields couple nonminimally to gravity and induce the Planck scale dynamically, once they develop vacuum expectation values. By means of the Gildener-Weinberg approach, we describe the inflationary dynamics in terms of a single scalar degree of freedom along the flat direction of the tree-level potential. The one-loop effective potential in the Einstein frame exhibits plateaus on both sides of the minimum and thus the model can accommodate both small and large field inflation. The inflationary predictions of the model are found to comply with the latest bounds set by the Planck collaboration for a wide range of parameters and the effect of the quadratic in curvature terms is to reduce the value of the tensor-to-scalar ratio.
Displayed: 24/12/2024 03:45