Moninder Singh Modgil

ROTATING BRANE WORLD BLACK HOLES

A five-dimensional rotating black string in a Randall–Sundrum brane world is considered. The black string intercepts the three-brane in a four-dimensional rotating black hole. The geodesic equations and the asymptotics in this background are discussed.

SEARCH FOR GLOBAL METRIC ANISOTROPY IN TYPE 1a SUPERNOVA DATA

We examine the Type 1a supernova data in order to determine if it shows any signal of large scale anisotropy. The anisotropy is modelled by an extended Godel metric, which incorporates expansion along with rotation. The model is smoothly connected to the usual FRW type, while expressing anisotropic metric effects depending on certain parameters. We find no significant signal of anisotropy in the data. We obtain bounds on an anisotropic redshift versus magnitude relationship, and accompanying parameters of the Godel–Obukhov metric.

GÖDEL TYPE METRICS IN RANDALL SUNDRUM MODEL

In this letter, we have considered a model of the universe filled with modified Chaplygin gas and another fluid (with barotropic equation of state) and its role in accelerating phase of the universe. We have assumed that the mixture of these two fluid models is valid from (i) the radiation era to

Black holes in brane worlds

\Lambda

Loschmidt's paradox, entropy and the topology of spacetime

CDM for

The Quark Gluon Pion Plasma

-1\le\gamma\le 1

Climate Control Using Nuclear Energy

and (ii) the radiation era to quiessence model for

Geometry of Time, Axiom of Choice and Neuro-Biological Quantum Zeno Effect

\gamma<-1

The Godel Universe: A Practical Travel Guide

. For these two fluid models, the statefinder parameters describe different phase of the evolution of the universe.Anisotropic cosmological models such as the Godel universe and its extensions – Godel type solutions, are embedded on a visible brane in the model 1 of Randall Sundrum. The size of the extra dimension is stabilized by tuning the rotation parameter to a very small value so that hierarchy problem can be solved. A limiting case also yields the Randall Sundrum 2 model. The angular velocity ω ~ 1 / a would be of O (ek|y|) which would be unacceptably large if ek|y| were adjusted to solve the hierarchy problem as normally formulated. Should one choose to reverse the choice of the fundamental and generated scales, ek|y| could turn out to be O (10-16) which would fall in the right range.

Bounds on Extended Godel-Type Metrics from Type Ia Supernova Data

A Kerr metric describing a rotating black hole is obtained on the three brane in a five-dimensional Randall-Sundrum brane world by considering a rotating five-dimensional black string in the bulk. We examine the causal structure of this space-time through the geodesic equations.