Master field on a fuzzy sphere Original Research Article

The O(N)-invariant field theory is considered on both an ordinary and a non-commutative sphere (fuzzy sphere). It is shown that in both cases large-N dominant fields (master fields) exist and their explicit forms are presented. They are found to mix the internal symmetry and the (fuzzy) space-time symmetry. It is also argued that the cutoff introduced by the fuzzy sphere plays an essential role in constructing the master field.