The limiting absorption principle for massless dirac operators, properties of spectral shift functions, and an application to the Witten Index of Non-Fredholm Operators - Carey, Alan L. 1949-; Gesztesy, Fritz 1953-; Levitina, Galina; Nichols, Roger; Sukochev, Fedor; Zanin, Dmitriy (EMS Press, 2023)