269 citations · 2.3k across the 34 of their papers we have counts for
6 papers · 1 filter
Dyon Spectrum in CHL Models
Dileep P. Jatkar, Ashoke Sen
We propose a formula for the degeneracy of quarter BPS dyons in a class of CHL models. The formula uses a modular form of a subgroup of the genus two modular group Sp(2,Z). Our pro…
Entropy Function for Heterotic Black Holes
Ashoke Sen
We use the entropy function formalism to study the effect of the Gauss-Bonnet term on the entropy of spherically symmetric extremal black holes in heterotic string theory in four d…
Black Hole Entropy Function and the Attractor Mechanism in Higher Derivative Gravity
Ashoke Sen
We study extremal black hole solutions in D dimensions with near horizon geometry AdS_2\times S^{D-2} in higher derivative gravity coupled to other scalar, vector and anti-symmetri…
Stretching the Horizon of a Higher Dimensional Small Black Hole
Ashoke Sen
There is a general scaling argument that shows that the entropy of a small black hole, representing a half-BPS excitation of an elementary heterotic string in any dimension, agrees…
Black Holes and the Spectrum of Half-BPS States in N=4 Supersymmetric String Theory
Ashoke Sen
The entropy of a half-BPS black hole in N=4 supersymmetric heterotic string compactification is independent of the details of the charge vector and is a function only of the norm o…
Black Holes, Elementary Strings and Holomorphic Anomaly
Ashoke Sen
In a previous paper we had proposed a specific route to relating the entropy of two charge black holes to the degeneracy of elementary string states in N=4 supersymmetric heterotic…