The parity of the Maslov index and the even cobordism category
Tom 188 / 2005
                    
                    
                        Fundamenta Mathematicae 188 (2005), 95-102                    
                                        
                        MSC: Primary 57R56.                    
                                        
                        DOI: 10.4064/fm188-0-5                    
                                    
                                                Streszczenie
We give a formula for the parity of the Maslov index of a triple of Lagrangian subspaces of a skew symmetric bilinear form over $\mathbb R$. 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.
 
             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                         
                                                            