(1) Problems of gravitational baryogenesis and possible resolution (2) Conformally Coupled General Relativity

by Prof. Elena Arbuzova + Andrej Arbuzov

(1) Dubna State University and Novosibirsk State University, Russia (2) Joint Institute for Nuclear Research, Dubna, Russia

at Particles and Fields Seminar

Mon, 24 Apr 2023, 14:00
Sacta-Rashi Building for Physics (54), room 207

Abstract

This week we will have two short 30 minutes talk from our visitors (guests of Eduardo)

(1) Name: Elena Arbuzova
Affiliations: Dubna State University and Novosibirsk State University, Russia
Title: Problems of gravitational baryogenesis and possible resolution
Abstract: It is shown that the traditional gravitational baryogenesis suffers from exponential instability of the curvature scalar. This rise of $R$ could be stabilized by an addition of the $R^2$-term into canonical Hilbert-Einstein action of General Relativity. As a result the explosive rise of curvature turns
into high frequency oscillations of $R$, which lead to an efficient particle production. The created particles may noticeably contribute to ultra high energy cosmic ray (UHECR) flux.

(2) Name: Andrej Arbuzov
Affiliation: Joint Institute for Nuclear Research, Dubna, Russia
Title: Conformally Coupled General Relativity
Abstract: A gravity model based on the conformal symmetry is presented. To specify the structure of the general coordinate transformations the Ogievetsky theorem is applied. The nonlinear symmetry realization approach is used. Canonical quantization is performed with the use of reparameterization invariant time and the Arnowitt-Deser-Misner foliation. Renormalizability of the constructed quantum gravity model is discussed. Application of nonlinear symmetry realization technique to gravity is studied. We identify the simplest extensions of the Poincare group suitable for nonlinear realization at the level of physical fields. Two simple models are proposed. The first one introduces additional scalar degrees of freedom that may be suitable for driving inflation. The second one describes states with well-defined mass that lack linear interaction with matter states. We argue that this phenomenon points out a necessity to draw a distinction between gravitational states with well-defined masses and states that participate in interaction with matter.

Created on 31-03-2023 by Chapman, Shira (schapman)
Updaded on 20-04-2023 by Chapman, Shira (schapman)