EPS-HEP2019

10-17 July 2019
Ghent
Europe/Brussels timezone

Cosmological constant as a quantum gravity correction to the QCD vacuum density

12 Jul 2019, 17:10
20m
ICC - Baeckeland 1 (Ghent)

ICC - Baeckeland 1

Ghent

Parallel talk Cosmology

Speaker

Roman Pasechnik (Lund university)

Description

To the zeroth order in gravitational interactions, the averaged QCD (quark-gluon) vacuum condensate density is dynamically self-screened and is eliminated at macroscopic space-time separations. We argue that the observable cosmological constant can then be generated as a quantum gravity correction to QCD vacuum energy density after the QCD phase transition epoch. In order to incorporate the latter, we compute the leading-order quantum correction to the classical Einstein equations due to metric fluctuations induced by the non-perturbative vacuum fluctuations of the gluon and quark fields in the quasi classical approximation (valid at the considered energy scales). The resulting contribution to the cosmological constant is positive and approaches the observed value within a factor of few.

Primary author

Roman Pasechnik (Lund university)