On perturbations of the isometric semigroup of shifts on the semiaxis

G. G. Amosov, A. D. Baranov, V. V. Kapustin

We study perturbations $({\tilde{\tau }}_t{)}_{t\ge 0}$ of the semigroup of shifts $({\tau }_t{)}_{t\ge 0}$ on $L^2({\mathbb{R}}_{+})$ with the property that ${\tilde{\tau }}_t-{\tau }_t$ belongs to a certain Schatten-von…