Related papers: Two-branes with variable tension model and the eff…
We study cosmology in a five-dimensional brane-world with a stabilizing effective potential for the radion and matter localized on the two branes. We consider the corrections induced by the Gauss-Bonnet contribution to the total action…
Time variation of fundamental constants, a strong signal of new physics, is analyzed comparing extant data with two phenomenological models. Results are discussed.
Codimension two branes play an interesting role in attacking the cosmological constant problem. Recently, in order to handle some problems in codimension two branes in Einstein gravity, Bostock {\it et al.} have proposed using…
The cosmological observation indicates that the effective equation of state parameter $w_{eff}$ varies with $z$: It changes from $w_{eff}>-1$ to $w_{eff}<-1$ at $z\sim 0.2$. We investigate under which condition it exhibits such behaviors…
We consider the propagation of gravitational waves in six dimensions induced by sources living on 3-branes in the context of a recent exact solution hep-th/0506050. The brane geometries are de Sitter and the bulk is a warped geometry…
We argue that topological matrix models (matrix models of the Kontsevich type) are examples of exact open/closed duality. The duality works at finite N and for generic `t Hooft couplings. We consider in detail the paradigm of the Kontsevich…
The scalar perturbations of thick braneworld models provide critical insights into their matter-geometry relationship, distinct from tensor modes. This work systematically investigates quasinormal modes and gravitational echoes from scalar…
We study five dimensional brane physics induced by an O(2) texture formed in one extra dimension. The model contains two 3-branes of nonzero tension, and the extra dimension is compact. The symmetry-breaking scale of the texture controls…
We study classical dynamics of a probe Dp-brane moving in a background sourced by a stack of Dp-branes. In this context the physics is similar to that of the effective action for open-string tachyon condensation, but with a power-law…
We derive exact solutions of the Einstein equations in the context of the Randall-Sundrum model with matter on the brane and in the bulk. We present two models in which the brane moves within a time-dependent bulk. We study the cosmological…
The notion of Lorentz violation in four dimensions is extended to a 5-dimensional brane-world scenario by utilizing a dynamical vector field assumed to point in the bulk direction, with Lorentz invariance holding on the brane. The…
One of the most interesting features of braneworld models is the existence of massive gravitational modes in addition to the usual massless one. Mixing of the modes which depends nontrivially on the inter-brane distance can be interpreted…
A general analysis of the induced brane dynamics is performed when the intrinsic curvature term is included in the action. Such a term is known to cause dramatic changes and is generically induced by quantum corrections coming from the bulk…
The braneworld scenario is studied and the effective action of 3-brane living in 5-dim. Minkowski space is constructed. This action is proved to be invariant under spontaneously broken scale and Weyl symmetries and to encode a model of…
We investigate a simple model of a stack of four dimensional cosmological branes in a five dimensional flat bulk via the use of a derived low-energy effective Hamiltonian for a `radion'-like field associated with brane displacements and…
In this review we describe our current understanding of the properties of open string tachyons on an unstable D-brane or brane-antibrane system in string theory. The various string theoretic methods used for this study include techniques of…
Recently, Pani, Sotiriou, and Vernieri explored a new theory of gravity by adding nondynamical fields, i.e., gravity with auxiliary fields [Phys. Rev. D 88, 121502(R) (2013)]. In this gravity theory, higher-order derivatives of matter…
We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time. The standard model matter fields live only on the 4D brane. The change of vacuum energy on the brane just gives rise to dynamical…
In this brief report, we summarize our recent studies in brane cosmology in both string theory and M-Theory on $S^{1}/Z_{2}$. In such setups, we find that the radion is stable and its mass, with a very conservative estimation, can be of the…
Braneworld models are interesting theoretical and phenomenological frameworks to search for new physics beyond the standard model of particles and cosmology. In this work, we discuss braneworld models whose gravitational dynamics are…