相关论文: Modified brane cosmologies with induced gravity, a…

According to the braneworld idea, ordinary matter is confined on a 3-dimensional space (brane) that is embedded in a higher-dimensional space-time where gravity propagates. In this work, after reviewing the limits coming from general…

By considering the p-brane motion in G/K symmetric space bulk we identify the G-invariant bulk metric in the solvable lie algebra gauge of the brane action. After calculating the Levi-Civita connection of this bulk metric we use it in the…

In brane-worlds, our universe is assumed to be a submanifold, or brane, embedded in a higher-dimensional bulk spacetime. Focusing on scenarios with a curved five-dimensional bulk spacetime, I discuss their gravitational and cosmological…

It has recently been pointed out that global solutions of Einstein's equations for a 3-brane universe embedded in 4 spatial dimensions give rise to a Friedmann equation of the form H ~ rho on the brane, instead of the usual H ~ (rho)^{1/2},…

We consider the possibility of getting accelerated expansion and w=-1 crossing in the context of a braneworld cosmological setup, endowed with a bulk energy-momentum tensor. For a given ansatz of the bulk content, we demonstrate that the…

Through modeling the universe as a symplectic 3-brane embedded in the bulk of N = 2 five-dimensional ungauged supergravity theory, the entire evolution of the universe can be interpreted from inflation to late-time acceleration without…

The Friedmann equation for a FRW-brane-world in a flat bulk is derived and applied to the accelerated expansion of the universe.

A new class of modified theory of gravity is introduced where the volume form becomes dynamical. This approach is motivated by unimodular gravity and can also be related to Brans-Dicke theory. On the level of the action, the only change…

The role of bulk matter quantum effects (via the corresponding effective potential discussed on the example of conformal scalar) and of boundary matter quantum effects (via the conformal anomaly induced effective action) is considered in…

We propose an interpretation for the cosmological constant problem based on modeling the universe as a 3-brane embedded in the bulk of 5-dimensional supergravity with hypermultiplets. When solving the modified Friedmann equations the…

In braneworld models a variable vacuum energy may appear if the size of the extra dimension changes during the evolution of the universe. In this scenario the acceleration of the universe is related not only to the variation of the…

We present an holographic model of the Dvali-Gabadadze-Porrati scenario with a Gauss-Bonnet term in the bulk. We concentrate on the solution that generalises the normal Dvali-Gabadadze-Porrati branch. It is well known that this branch…

The global geometries of bulk vacuum space-times in the brane-universe models are investigated and classified in terms of geometrical invariants. The corresponding Carter-Penrose diagrams and embedding diagrams are constructed. It is shown…

We derive the four-dimensional field equations for the induced metric and scalar field on the world-volume of a 3-brane in a five-dimensional bulk with Einstein gravity plus a self-interacting scalar field. We calculate the effective…

In the present paper the gauge-invariant formalism is developed for perturbations of the brane-world model in which our universe is realized as a boundary of a higher-dimensional spacetime. For the background model in which the bulk…

Braneworld models with variable brane tension $\lambda $ introduce a new degree of freedom that allows for evolving gravitational and cosmological constants, the latter being a natural candidate for dark energy. We consider a thermodynamic…

We investigate the cosmological consequences of a two brane system embedded in a higher dimensional background spacetime with a compactified extra dimension described with an action that include the intrinsic curvature for each brane. We…

We study scalar cosmological perturbations in a braneworld model with a bulk Gauss-Bonnet term. For an anti-de Sitter bulk, the five-dimensional perturbation equations share the same form as in the Randall-Sundrum model, which allows us to…

In the study of three-brane cosmological models, an unusual law of cosmological expansion on the brane has been reported. According to this law, the energy density of matter on the brane quadratically enters the right-hand side of the new…

An alternative way of explaining astrophysical observations without dark matter is proposed. In the braneworld scenario, where our universe is visualised as a 4-dimensional hypersurface embedded in a higher dimensional spacetime, the…