Exact and microscopic one-instanton calculations in N=2 supersymmetric   Yang-Mills theories
  We study the low-energy effective theory in N=2 super Yang-Mills theories by microscopic and exact approaches. We calculate the one-instanton correction to the prepotential for any simple Lie group from the microscopic approach. We also study the Picard-Fuchs equations and their solutions in the semi- classical regime for classical gauge groups with rank r \leq 3. We find that for gauge groups G=A_r, B_r, C_r (r \leq 3) the microscopic results agree with those from the exact solutions. 
Katsushi Ito (Univ. of Tsukuba) and Naoki Sasakura (Tohoku Univ.)