Noncommutative gauge theory on fuzzy sphere from matrix model

We derive a noncommutative U(1) and U(n) gauge theory on the fuzzy sphere f rom a three-dimensional matrix model by expanding the model around a classi cal solution of the fuzzy sphere. Chem-Simons term is added in the matrix m odel to make the fuzzy sphere as a classical solution of the model. Majoran a mass term is also added to make it supersymmetric. We consider two large N limits, one corresponding to a gauge theory on a commutative sphere and t he other to that on a noncommutative plane, We also investigate stability o f the fuzzy sphere by calculating one-loop effective action around classica l solutions. In the final part of this paper, we consider another matrix mo del which gives a supersymmetric gauge theory on the fuzzy sphere, In this matrix model, only Chern-Simons term is added and supersymmetry transformat ion is modified. (C) 2001 Published by Elsevier Science B.V.