English

String-inspired running-vacuum cosmology, quantum corrections and the current cosmological tensions

General Relativity and Quantum Cosmology 2023-07-28 v2 High Energy Physics - Theory

Abstract

In the context of a string-inspired running vacuum model (RVM) of cosmology with anomalies and torsion-induced axion-like fields, we discuss quantum corrections to the corresponding energy density, in approximately de Sitter eras, during which the Hubble parameter H(t)H(t) varies very slowly with the cosmic time tt. Such corrections arise either from graviton loops in the corresponding gravitational theory, or from path integration of massive quantum matter fields. They depend logarithmically on H(t)H(t), in the form Hnln(H2)H^n\, {\rm ln}(H^2), n2Z+n \in 2Z^+. In the modern eras, for which the n=2n=2 terns are dominant, such corrections may contribute to an alleviation of the currently observed cosmological H0H_0 and structure-growth tensions. In particular, we argue that such an effect is accomplished for a (dynamically-broken) supergravity-based RVM cosmological model. In the current de-Sitter era, for this case, rather surprisingly, the quantum graviton corrections dominate those due to matter fields, provided the scale of the primordial (pre-RVM inflation) dynamical breaking of local supersymmetry lies near the reduced Planck scale, which is a natural assumption in the context of the model.

Keywords

Cite

@article{arxiv.2307.13130,
  title  = {String-inspired running-vacuum cosmology, quantum corrections and the current cosmological tensions},
  author = {Nick E. Mavromatos and Joan Solà Peracaula and Adrià Gómez-Valent},
  journal= {arXiv preprint arXiv:2307.13130},
  year   = {2023}
}

Comments

12 pages, latex (uses special (Springer Proceedings) macros), one pdf figure incorporated; Invited plenary talk (NEM) at 40th Conference on Recent Developments in High Energy Physics and Cosmology (HEP2023, 5-7 April 2023, U. of Ioannina (Greece)),based partly on e-Print:2305.15774 [gr-qc]. arXiv admin note: text overlap with arXiv:2306.08064.Corrections in references, no effects on conclusions

R2 v1 2026-06-28T11:39:08.767Z