Cosmological Dark Matter from a Bulk Black Hole

Autor: Fichet, Sylvain, Megias, Eugenio, Quiros, Mariano
Rok vydání: 2022
Předmět:
Zdroj: Phys.Rev.D 107 (2023) 11, 115014
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevD.107.115014
Popis: We study the cosmology of a three-brane in a specific five-dimensional scalar-gravity (i.e. soft-wall) background, known as the linear dilaton background. We discover that the Friedmann equation of the brane-world automatically contains a term mimicking pressureless matter. We propose to identify this term as dark matter. This dark matter arises as a projection of the bulk black hole on the brane, which contributes to the brane Friedmann equation via both the Weyl tensor and the scalar stress tensor. The nontrivial matter-like behavior is due to an exact cancellation between the Weyl and scalar pressures. We show that the Newtonian potential only receives a mild short-distance correction going as inverse distance squared, ensuring compatibility of the linear dilaton brane-world with observed 4D gravity. Our setup can be viewed as a consistent cosmological description of the holographic theories arising in the linear dilaton background. We also present more general scalar-gravity models where the brane cosmology features an effective energy density whose behavior smoothly interpolates between dark radiation, dark matter and dark energy depending on a model parameter.
Comment: v2: 7 pages, 2 figures. Text improved, model in Sec. V.A. added, references added, matches journal version
Databáze: arXiv