# XXIV SIGRAV Conference on General Relativity and Gravitation

Sep 7 – 9, 2021
Urbino/Palazzo Battiferri
Europe/Rome timezone

## New equations for relativistic cosmology

Sep 8, 2021, 11:30 AM
30m
Urbino/Palazzo Battiferri

#### Urbino/Palazzo Battiferri

Via Aurelio Saffi, 42, 61029 Urbino PU
Gravity theory

### Speaker

Giampiero Esposito (Istituto Nazionale di Fisica Nucleare)

### Description

We propose a model where, in the Einstein equations, the right-hand side is modified by the addition of a term proportional to the symmetrized partial contraction of the Ricci tensor with the energy-momentum tensor. Bearing in mind the existence of a natural length scale given by the Planck length, dimensional analysis shows that such a term yields a correction linear in hbar to the classical term that is instead just proportional to the energy-momentum tensor. One then obtains an effective energy-momentum tensor that consists of three contributions: pure energy part, mechanical stress, and thermal part. The pure energy part has the appropriate property for dealing with the dark sector of modern relativistic cosmology. Such a theory coincides with general relativity in
vacuum, and the resulting field equations are here solved for a Dunn and
Tupper metric, for departures from an interior Schwarzschild solution as
well as for a Friedmann-Lemaitre-Robertson-Walker universe.

### Primary author

Giampiero Esposito (Istituto Nazionale di Fisica Nucleare)