Study of Branes with Variable Tension

Abstract

In this work we study a brane world model with variable tension which gives rise to four dimensional cosmologies. The brane worlds obtained corresponds to Eötvös branes whose (internal) geometry can be casted as either a four dimensional (A)dS 4 or a standard radiation period cosmology. The matter dominated period is discussed as well.

Brane with variable tension as a possible solution to the problem of the late cosmic acceleration

“…In order to explore the background cosmology, we propose the following ansatz for the VBT:λ(a) = a −n → λ(z) = (z + 1) n , where n ∈ R is the free parameter and λ(1) =λ(0) = 1 for the scale factor and redshift respectively. Other authors have already analyzed the casê λ(a) = 1 − a −1 → |λ(z)| = z [15][16][17][18][19][20][21][22][23]. This form (n = 1) is inferred through the Eötvös law λ = K(T c − T ), where K is a constant, T c is a critical temperature, and T is the Universe temperature (see [17] for details).…”

“…However, the majority of them (including the Randall and Sundrum (RS) 1 [11,12] models) 1 RS models are divided in the case of two (RSI) and one brane achieve a stable late cosmic acceleration only by including DE [13,14]. Although models with variable brane tension (VBT), λ(t) ∝ a(t), sourcing from thermodynamics assumptions (Eötvös law) have been studied previously 2 [15][16][17][18][19][20][21][22][23], they either have not been contrasted with recent observations or still need the introduction of a DE fluid to reproduce the late acceleration.…”