Cosmological consequences of Brans–Dicke theory in 4D from 5D scalar-vacuum
Dipartimento di Fisica E.R. Caianiello, Universitá di Salerno, Via G. Paolo II, 84084, Fisciano, SA, Italy
2 INFN - Gruppo Collegato dì Salerno, Via G. Paolo II, 84084, Fisciano, SA, Italy
3 Dipartimento di Scienze e Tecnologie, Universitá del Sannio, Via dei Mulini (CUBO), 82100, Benevento, Italy
Accepted: 14 January 2024
Published online: 9 February 2024
We study 5D Brans–Dicke theory in the framework of (gravitational) baryogenesis and primordial light element formation. Such a model is able to explain the present cosmic accelerated expansion without recurring to matter fields in 5D or dark energy in 4D. In fact, the 5D to 4D reduction arises a space-matter tensor of geometrical origin that plays the role of a new ingredient on-shell. For an isotropic and homogeneous Universe, the cosmological equations admit a power-law solution of the scale factor, , we constrain the exponential factor by using the present bounds on the matter–antimatter asymmetry in the Universe and Big Bang Nucleosynthesis. A possible connection with dark matter relic abundance is also discussed.
© The Author(s) 2024
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