A Class Of Ns1-p Black Hole Entropy

Black holes have long been objects of interest in theoretical physics.and more recently also in experimental astrophysics.The quantum theory of black holes presents many paradoxes.It is important to ask how these paradoxes are to be solved,for answers will likely lead to deep changes in our understanding of quantum gravity, string theory is a consistent theory of quantum gravity,it is a theory with no free parameters.We should therefore ask how this theory deals with black holes.We need to discuss is a class of NS1-P black holes entropy problem.Benkenstein entropy is Sbek=A/4G,this entropy must be true to the hole if we are to prevent a violation of the second law of thermodynamics.This is our starting point. The low energy effective action of typeⅡB/ⅡA superstring theory is typeⅡB/ⅡA supergravity.The black holes which we will discuss later in this paper ares solution of supergravity.We need to make some introdution on thesuperstring,supergravity T-duality,S-duality, Kaluza-Klein reduction.Since we are interested in bosonic solution,we will only discuss the bosnic part.We hope to solve a NS1-P black hole's entropy and find it physical interpretation.First,we will discuss S-duality,Which gives the equivalence of the NS1-P system's action and Dl-P system's action.The NS1-P black holes is the solution of the NS1 supergravity low energy effective action.So, the NS1-P black holes is equivalent to Dl-P black holes.We know that entropy is not change under S-duality.if can solve the entropy of the NS1-P system,the entropy of the D1-P system that can be known by used the S-duality.We try to construct a 5-dimensional black hole by dimensional reduction of the NS1-P System of 10-dimensional typeⅡB. And transform the 5-dimensinal string frame to Einstein frame to compute the NS1-P system's entropy.We know that exist en equivalence between momentum and charge in string theory.hope to get by calulating the relationship between the entropy and charge.