Gravitational matter creation, multi-fluid cosmology and kinetic theory

S. R. G. Trevisani; J. A. S. Lima

doi:10.1140/epjc/s10052-023-11301-8

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2023) 83: 244
https://doi.org/10.1140/epjc/s10052-023-11301-8

Regular Article - Theoretical Physics

Gravitational matter creation, multi-fluid cosmology and kinetic theory

S. R. G. Trevisani and J. A. S. Lima^b

Departamento de Astronomia, Universidade de São Paulo, Rua do Matão, 1226, 05508-900, São Paulo, SP, Brazil

^b jas.lima@iag.usp.br

Received: 19 May 2022
Accepted: 5 February 2023
Published online: 23 March 2023

Abstract

A macroscopic and kinetic relativistic description for a decoupled multi-fluid cosmology endowed with gravitationally induced particle production of all components is proposed. The temperature law for each decoupled particle species is also kinetically derived. The present approach points to the possibility of an exact (semi-classical) quantum-gravitational kinetic treatment by incorporating back reaction effects for an arbitrary set of dominant decoupled components. As an illustration we show that a cosmology driven by creation of cold dark matter and baryons (without dark energy) evolves like $Λ$ $\Lambda$ CDM. However, the complete physical emulation is broken when photon creation is added to the mixture thereby pointing to a crucial test in the future. The present analysis also open up a new window to investigate the Supernova-CMB tension on the values of $H_{0}$ $$H_0$$ , as well as the $S_{8}$ $$S_8$$ tension since creation of all components changes slightly the CMB results and the expansion history both at early and late times. Finally, it is also argued that cross-correlations between CMB temperature maps and the Sunyaev–Zeldovich effect may provide a crucial and accurate test confronting extended CCDM and $Λ$ $\Lambda$ CDM models.

© The Author(s) 2023

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