Indefinite orthogonal group

In mathematics, the indefinite orthogonal group, O ⁡ ( p , q ) {\displaystyle \operatorname {O} (p,q)} is the Lie group of all linear transformations of an n {\displaystyle n} -dimensional real vector space that leave invariant a nondegenerate, symmetric bilinear form of signature ( p , q ) {\displaystyle (p,q)} , where n = p + q {\displaystyle n=p+q} . It is also called the pseudo-orthogonal group or generalized orthogonal group.

Source: Wikipedia — Indefinite orthogonal group (CC BY-SA 4.0)