Drinfeld-Manin instanton and its noncommutative generalization

The Drinfeld-Manin construction of U(N)instanton is reformulated in the ADHM formulism,which gives explicit general solutions of the ADHM constraints for U(N)(N ≥ 2k-1)k-instantons.For the N<2k-1 case,implicit results are given systematically as further constraints.We find that this formulism can easily be generalized to the noncommutative case,where the explicit solutions are also obtained.