The integral form of APS boundary conditions in the bag model

A A Abrikosov, A Wipf
2007 Journal of Physics A: Mathematical and Theoretical  
We propose an integral form of Atiah-Patodi-Singer spectral boundary conditions (SBC) and find explicitly the integral projector onto SBC for the 3-dimensional spherical cavity. After discussion of a simple example we argue that the relation between the projector and fermion propagator is universal and stays valid independently of the bag form and space dimension.
doi:10.1088/1751-8113/40/19/016 fatcat:fjx7swe4uvfp7nq4rsotzdhe4m