Atiyah-Patodi-Singer boundary condition and a splitting formula of a spectral flow

英文摘要：

We describe a relation between Atiyah-Patodi-Singer boundary condition and a global elliptic boundary condition which naturally appears in formulating a splitting formula for a spectral flow, when we decompose the manifold into two components. Then we give a variant of the splitting formula with the Hoermander index as a correction term.