Das, Saurya

Permanent URI for this collection

https://opus.uleth.ca/handle/10133/3587

Browse

Browsing Das, Saurya by Author "Dasgupta, Arundhati"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Black hole emission rates and the AdS/CFT correspondence
    (SISSA, 1999) Das, Saurya; Dasgupta, Arundhati
    We study the emission rates of scalar, spinor and vector particles from a 5 dimensional black hole for arbitrary partial waves. The solution is lifted to 6 dimensions, and the near horizon BTZ S3 geometry of the black hole solution is probed to determine the greybody factors. We show that the exact decay rates can be reproduced from a (1 + 1)-dimensional conformal eld theory which lies on the boundary of the near horizon geometry. The AdS/CFT correspondence is used to determine the dimension of the CFT operators corresponding to the bulk elds. These operators couple to plane waves incident on the CFT from in nity to produce emission in the bulk.
  • Thumbnail Image
    Item
    High energy effects on D-brane and black hole emission rates
    (American Physical Society, 1997) Das, Saurya; Dasgupta, Arundhati; Sarkar, Tapobrata
    We study the emission of scalar particles from a class of near-extremal five-dimensional black holes and the corresponding D-brane configuration at high energies. We show that the distribution functions and the black hole greybody factors are modified in the high energy tail of the Hawking spectrum in such a way that the emission rates exactly match. We extend the results to charged scalar emission and to four dimensions.
  • Thumbnail Image
    Item
    Planckian scattering of D-branes
    (Elsevier BV North Holland, 1988) Das, Saurya; Dasgupta, Arundhati; Ramadevi, P.; Sarkar, Tapobrata
    We consider the gravitational scattering of point particles in four dimensions, at Planckian centre of mass energy and low momentum transfer, or the eikonal approximation. The scattering amplitude can be exactly computed by modelling point particles by very generic metrics. A class of such metrics are black hole solutions obtained from dimensional reduction of p-brane solutions with one or more Ramond-Ramond charges in string theory. At weak string coupling, such black holes are replaced by a collection of wrapped D-branes. Thus, we investigate eikonal scattering at weak coupling by modelling the point particles by wrapped D-branes and show that the amplitudes exactly match the corresponding amplitude found at strong coupling. We extend the calculation for scattering of charged particles.