COBORDISM GROUP OF MORSE FUNCTIONS ON UNORIENTED SURFACES
Boldizsár Kalmár · Kyushu Journal of Mathematics · 2005
Ikegami and Saeki have proved that the cobordism group of Morse functions on oriented surfaces is an infinite cyclic group. Their method is applicable, with a little modification, to the computation of the cobordism group of Morse functions on unoriented surfaces. We prove that this group is isomorphic to the direct sum of the infinite cyclic group and the finite group of order two.