We give a formula for the parity of the Maslov index of a triple of Lagrangian subspaces of a skew symmetric bilinear form over ℝ. We define an index two subcategory (the even subcategory) of a 3-dimensional cobordism category. The objects of the category are surfaces equipped with Lagrangian subspaces of their real first homology. This generalizes a result of the first author where surfaces are equipped with Lagrangian subspaces of their rational first homology.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm188-0-5, author = {Patrick M. Gilmer and Khaled Qazaqzeh}, title = {The parity of the Maslov index and the even cobordism category}, journal = {Fundamenta Mathematicae}, volume = {185}, year = {2005}, pages = {95-102}, zbl = {1157.57303}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm188-0-5} }
Patrick M. Gilmer; Khaled Qazaqzeh. The parity of the Maslov index and the even cobordism category. Fundamenta Mathematicae, Tome 185 (2005) pp. 95-102. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm188-0-5/