A note on the generalized neutral orthogonal group in dimension four

Abstract

We study the main properties of the generalized neutral orthogonal group O(2, 2) and its Lie algebra o(2, 2). We also give an explicit isomorphism between the Lie algebras su(1, 1) ⊕ su(1, 1) and o(2, 2). We use this isomorphism to classify the subalgebras of o(2, 2).