Observational constraints on Chaplygin cosmology in a braneworld scenario with induced gravity and curvature effect

Abstract

We study cosmological dynamics and late-time evolution of an extended induced gravity braneworld scenario. In this scenario, curvature effects are taken into account via the Gauss-Bonnet term in the bulk action and there is also a Chaplygin gas component on the brane. We show that this model mimics an effective phantom behaviour in a relatively wider range of redshifts than previously formulated models. It also provides a natural framework for smooth crossing of the phantom-divide line due to presence of the Chaplygin gas component on the brane. We confront the model with observational data from Type Ia supernovae, cosmic microwave background and baryonic acoustic oscillations to constrain the model parameter space.

Thermodynamical analysis on a braneworld scenario with curvature corrections

“…This can be achieved either by means of phantom fields, that on the other hand suffer from instabilities [24], or by other approaches that mimic this phantom-like behaviour. In the model under analysis, in which UV modifications are included by considering the stringy effect via the GB term in the bulk, and IR modifications are due to the IG effect, a Chaplygin gas fluid on the brane provides a smooth crossing of the cosmological constant line [25]. In fact, this component is characterised by a cross-over length scale below which the gas behaves as pressureless fluid and above which it mimics a cosmological constant.…”

On the concordance of cosmological data in the case of the generalized Chaplygin gas

“…This generated again a large interest in the Chaplygin cosmologies and its variants, see e. g. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. Most papers assume a flat universe when the allowed parameter space is estimated according to various cosmological data.…”

Gauss-Bonnet Braneworld Cosmology with Modified Induced Gravity on the Brane

“…We note that this scenario is UV/IR complete in some sense, since it contains both the Gauss-Bonnet term as a string-inspired modification of the UV (ultra-violet) sector and the induced gravity as IR (infra-red) modification to the General Relativity. The cosmological dynamics of this GBIG scenario is described fully by the following Friedmann equation [81][82][83][84]]…”

“…Note that when one adopts the positive sign, the above equation can be reduced to the generalized DGP model as α → 0 , but the branch with negative sign cannot be reduced to the generalized DGP model in this regime. Therefore, we just consider the plus sign of the above equation [81][82][83][84]. We note that depending on the choice of the bulk space, the brane FRW equations are different (see [85] for details).…”

“…We note that this equation can be derived using the generalized junction conditions on the brane straightforwardly, see[81][82][83][84].…”