N=2 instanton calculus in closed string background

作者：Billo Marco^*; Frau Marialuisa; Lerda Alberto

来源：Progress of Theoretical Physics - Supplement, 2007, (171): 279-290.

In this contribution we describe how to obtain instanton effects in four dimensional gauge theories by computing string scattering amplitudes in D3/D(-1) brane systems. In particular we study a system of fractional D3/D(-1) branes in a Z(2) orbifold and in a Ramond-Ramond closed string background, and show that it describes the gauge instantons of N = 2 super Yang-Mills theory and their interactions with the graviphoton of N = 2. Using string theory methods we compute the prepotential of the effective gauge theory exploiting the localization methods of the instanton calculus, showing that this leads to the same information given by the topological string.

• 出版日期2007