Spectral flow inside essential spectrum IV: $F^{\ast }F$ is a regular direction

Nurula Azamov

Let~$H_0$ and~$V$ be self-adjoint operators such that~$V$ admits a factorisation $V=F^{\ast }JF$ with bounded self-adjoint $J$ and $|H_0{|}^{1/2}$-compact~$F.$ Flow of singular spectrum…