We find all m-spin structures on Klein surfaces of genus larger than one. An
m-spin structure on a Riemann surface P is a complex line bundle on P whose
m-th tensor power is the cotangent bundle of P. A Klein surface can be
described by a pair (P,tau), where P is a Riemann surface and tau is an
anti-holomorphic involution on P. An m-spin structure on a Klein surface
(P,tau) is an m-spin structure on the Riemann surface P which is preserved
under the action of the anti-holomorphic involution tau. We determine the
conditions for the existence and give a complete description of all real m-spin
structures on a Klein surface. In particular, we compute the number of m-spin
structures on a Klein surface (P,tau) in terms of its natural topological
invariants.Comment: v3: minor corrections; v2: 29 pages, 4 figures; typos corrected,
Theorems 4.3 and 4.4 rephrase
