It has been believed that topology and signature change of the universe can only happen accompanied by singularities in classical or instantons in quantum gravity. In this note, we point out however that in the braneworld context, such an event can be understood as a classical, smooth event. We supply some explicit examples of such cases, starting from the Dirac-Born-Infeld action. Topology cha...

We investigate how braneworld gravity affects gravitational collapse and black hole formation by studying Oppenheimer-Snyder-like collapse on a Randall-Sundrum type brane. Without making any assumptions about the bulk, we show that the exterior spacetime on the brane is non-static. In the special case where there is no matter but only collapsing Weyl " dark radiation " , a static black hole may...

This will be a somewhat theoretical review of models and mechanisms for generating soft explicit supersymmetry breaking terms in the MSSM. There won’t be much signal phenomenology except in a few illustrative cases. Also, I shall be somewhat antihistorical in first talking about gauge mediation and then coming to gravity mediation since my subsequent topics, i.e. AMSB, gaugino mediation as well...

The brane cosmology scenario is based on the idea that our Universe is a 3−brane embedded in a five-dimensional bulk. In this work, a general class of braneworld wormholes is explored with R 6= 0, where R is the four dimensional Ricci scalar, and specific solutions are further analyzed. A fundamental ingredient of traversable wormholes is the violation of the null energy condition (NEC). Howeve...

The behaviour of the distance between two branes (the 'radion') in a braneworld model with a bulk scalar field is investigated. We show that the BPS conditions of supergravity ensure that the dynamics of the scalar field and the radion are not independent ; we derive the four-dimensional effective action, showing that the effective theory is of scalar–tensor nature, coupling the radion to four-...

Motivated by stringy considerations, Randall & Sundrum have proposed a model where all the fields and particles of physics, save gravity, are confined on a 4-dimensional brane embedded in 5-dimensional anti-deSitter space. Their scenario features a stable bound state of bulk gravity waves and the brane that reproduces standard general relativity. We demonstrate that in addition to this zero-mod...

Motivated by stringy considerations, Randall & Sundrum have proposed a model where all the fields and particles of physics, save gravity, are confined on a 4-dimensional brane embedded in 5-dimensional anti-deSitter space. Their scenario features a stable bound state of bulk gravity waves and the brane that reproduces standard general relativity. We demonstrate that in addition to this zero-mod...

We develop the general formalism to study the low energy regime of the brane world. We apply our formalism to the single brane model where the AdS/CFT correspondence will take an important role. We also consider the two-brane system and show the system is described by the quasi-scalar tensor gravity. Our result provides a basis for predicting CMB fluctuations in the braneworld models.

A bstract We investigate the appearance of islands when a closed universe with gravity is entangled non-gravitating quantum system. use braneworlds in three-dimensional multiboundary wormhole geometries as model to explore what happens system has several components. The braneworld can be either completely contained entanglement wedge one systems or split between them. In former case, other lead...