Biennial Report 2005-2007 - Saha Institute of Nuclear Physics

Theoretical Physics 5D(p − 4)-branes (N 2 ), the number of ¯D(p − 4)-branese ( ¯N 2 ) and the tachyon vev T. We show thatthe solution and the ADM mass capture all the required properties and give a correct descriptionof the tachyon condensation for the intersecting brane-antibrane system.Hua Bai†, Jian-Xin Lu†, Shibaji RoyTheo1.2.1.10 Non-SUSY p-branes delocalized in two directions, tachyon condensation andT-dualityWe here give the construction of non-supersymmetric p-branes delocalized in two transverse spatialdirections in supergravities in arbitrary dimensions (d). These solutions are characterized by fiveparameters. We show how these solutions in d = 10 interpolate between D(p+2)-anti-D(p+2) branesystem, non-BPS D(p + 1)-branes (delocalized in one direction) and BPS Dp-branes by adjustingand scaling the parameters in suitable ways. This picture is very similar to the descent relationsobtained by Sen in the open string effective description of non-BPS D(p + 1) brane and BPS Dpbraneas the respective tachyonic kink and vortex solutions on the D(p + 2)-anti-D(p + 2) branesystem (with some differences). We compare this process with the T-duality transformation.Jian-Xin Lu†, Shibaji RoyTheo1.2.1.11 Intersecting non-SUSY p-brane with chargeless 0-brane as black p-braneUnlike BPS p-brane, non-supersymmetric (non-susy) p-brane could be either charged or chargeless.Here we construct an intersecting non-susy p-brane with chargeless non-susy q-brane by takingT-dualities along the delocalized directions of the non-susy q-brane solution delocalized in (p − q)transverse directions (where p ≥ q). We show that when q = 0 the intersecting charged as well aschargeless non-susy p-brane with chargeless 0-brane can be mapped by a coordinate transformationto black p-brane when two of the four parameters characterizing the solution take some specialvalues. We observe that parameters characterizing the black brane and the related dynamics arein general in a different branch of the parameter space from those describing the brane-antibraneannihilation process.Hua Bai†, Jian-Xin Lu†, Shibaji RoyTheo1.2.1.12 Hawking temperature from tunnelling formalismIt has recently been suggested that the attempt to understand Hawking radiation as tunnellingacross black hole horizons produces a Hawking temperature double the standard value. It is explainedhere how one can obtain the standard value in the same tunnelling approach.Parthasarathi MitraTheo