We address the problem about under what conditions an endomorphism having a
dense orbit, verifies that a sufficiently close perturbed map also exhibits a
dense orbit. In this direction, we give sufficient conditions, that cover a
large class of examples, for endomorphisms on the n-dimensional torus to be
robustly transitive: the endomorphism must be volume expanding and any large
connected arc must contain a point such that its future orbit belong to an
expanding region.Comment: 32 pages, 13 figure