Generalized Mandelstam-Leibbrandt regularization

Algebraic noncovariant gauges are used often in string theory, Chern-Simons theory, and gravitation and gauge theories. Loop integrals, however, have spurious singularities that need to be regularized. The most popular and consistent regularization is the Mandelstam-Leibbrandt (ML) prescription. This paper extends the ML prescription outside the light cone. It shares all the properties of light cone ML regularization: it preserves naive power counting and gauge invariance. Moreover, using dimensional regularization, we get a closed form for the basic integrals, including divergent and finite pieces. These results simplify calculations in gauge theories and open new avenues for applications in nonlocal models.