Intersecting orbifold planes and local anomaly cancellation in M-theory

A systematic program is developed for analyzing and canceling local anomalies on networks of intersecting orbifold planes in the context of M-theory, Through a delicate balance of factors, it is discovered that local anomaly matching on the lower-dimensional intersection of two orbifold planes may require twisted matter on those planes which do not conventionally support an anomaly (such as odd-dimensional planes). In this way, gravitational anomalies can, in principle, tell us about (twisted) gauge groups on subspaces which are not necessarily ten-, six- or two-dimensional. An example is worked out for the case of an S-1/Z(2) x T-4/Z(2) orbifold and possible implications for four-dimensional physics are speculated on. (C) 1999 Elsevier Science B.V. All rights reserved.