The Nielsen-Ninomiya ``No-Go'' Theorem is False

Abstract

The Nielsen-Ninomiya no-go theorem asserts that chiral Weyl~(``neutrino'') fields cannot exist on lattices. However, the actual mathematical arguments advanced in the theorem fail to make that case. The theorem leaves the problem of lattice neutrinos completely open; it identifies no obstacle which would prevent us from discretizing chiral theories. (INFORMAL ABSTRACT: Have you too, like every second person in the field, been citing the Nielsen-Ninomiya theorem but have not read or analyzed it? Then, this paper will wake you up. Reading it is a prerequisite to doing any good work in chiral lattice physics.)