Spectral flow for real skew-adjoint Fredholm operators

Autor: Carey, Alan L., Phillips, John, Schulz-Baldes, Hermann
Rok vydání: 2016
Předmět:
Druh dokumentu: Working Paper
Popis: An analytic definition of a $\mathbb{Z}_2$-valued spectral flow for paths of real skew-adjoint Fredholm operators is given. It counts the parity of the number of changes in the orientation of the eigenfunctions at eigenvalue crossings through $0$ along the path. The $\mathbb{Z}_2$-valued spectral flow is shown to satisfy a concatenation property and homotopy invariance, and it provides an isomorphism on the fundamental group of the real skew-adjoint Fredholm operators. Moreover, it is connected to a $\mathbb{Z}_2$-index pairing for suitable paths. Applications concern the zero energy bound states at defects in a Majorana chain and a spectral flow interpretation for the $\mathbb{Z}_2$-polarization in these models.
Comment: final corrections before publication in J. Spectral Theory
Databáze: arXiv