相关论文: Self-tuning in an Outgoing Brane Wave Model

We investigate singular geometries which can be associated with warped branes in arbitrary dimensions. If the brane tension is allowed to be variable, the extremum condition for the action requires additional constraints beyond the solution…

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…

We study brane-world models with variable brane tension and compute corrections to the horizon of a black string along the extra dimension. The four-dimensional geometry of the black string on the brane is obtained by means of the minimal…

Using a metric-based formalism to treat cosmological perturbations, we discuss the connection between anisotropic stress on the brane and brane bending. First we discuss gauge-transformations, and draw our attention to gauges, in which the…

Branes are ubiquitous elements of any low-energy limit of string theory. We point out that negative tension branes violate all the standard energy conditions of the higher-dimensional spacetime they are embedded in; this opens the door to…

We consider a recently proposed setup where a codimension one brane is embedded in the background of a smooth domain wall interpolating between AdS and Minkowski minima. Since the volume of the transverse dimension is infinite, bulk…

We consider a blown-up 3-brane, with the resulting geometry R^(3,1) \times S^(N-1), in an infinite-volume bulk with N > 2 extra dimensions. The action on the brane includes both an Einstein term and a cosmological constant. Similar setups…

By considering 5--dimensional cosmological models with a bulk filled with a perfect fluid and a cosmological constant, we have found regular instantonic solution which is free from any singularity at the origin of the extra--coordinate and…

In this thesis we investigate some aspects of the dramatic consequences of supersymmetry breaking on string vacua. In particular, we focus on the issue of vacuum stability in ten-dimensional string models with broken, or without,…

From the dynamics of a brane-world with matter fields present in the bulk, the bulk metric and the black string solution near the brane are generalized, when both the dynamics of inhomogeneous dust/generalized dark radiation on the…

We show that a four-dimensional equation of state for a cosmological constant term arises from a perfect fluid in the bulk in the context of a gravity model where the scalar curvature is non-minimally coupled to the perfect fluid Lagrangian…

We discuss theories in which the standard-model particles are localized on a brane embedded in space-time with large compact extra dimensions, whereas gravity propagates in the bulk. In addition to the ground state corresponding to a…

We construct an intersecting brane configuration in six-dimensional space with one extra space-like and one extra time-like dimensions. With a certain additional symmetry imposed on the extra space-time we have found that effective…

In the context of brane cosmology, a scenario where our universe is a 3+1-dimensional surface (the ``brane'') embedded in a five-dimensional spacetime (the ``bulk''), we study geometries for which the brane is anisotropic - more…

We propose a codimension two warped braneworld model within the teleparallel $f(T)$ gravity. By assuming a global vortex as the source, we found a $l=0$ vortex solution that yields to a thick string-like brane. Asymptotically, the bulk…

The vacuum energy density arising from the broken supersymmetry of the (standard-model) fields living on a brane cannot be fully "off-loaded" to the bulk: even assuming the existence of an effective "self-tuning" mechanism, a small fraction…

We derive two classes of brane-world solutions arising in the presence of a bulk scalar field. For static field configurations, we adopt a time-dependent, factorizable metric ansatz that allows for radion stabilization. The solutions are…

We study brane-world solutions of five-dimensional supergravity in singular spaces. We exhibit a self-tuned four-dimensional cosmological constant when five-dimensional supergravity is broken by an arbitrary tension on the brane-world. The…

Brane world scenarios offer a way of ensuring that a Poincare invariant four dimensional world can emerge, without fine tuning, as a solution to the equations of motion of an effective action. We discuss the different ways in which this…

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…