One-parameter groups of isometries on Hardy spaces of the torus: spectral theory

Earl Berkson, Horacio Porta
1977 Transactions of the American Mathematical Society  
The spectral theory of the infinitesimal generator of an arbitrary one-parameter group of isometries on Hp of the torus, 1 < p < oo, p # 2, is considered. In particular, the spectrum of the generator is determined.
doi:10.1090/s0002-9947-1977-0451035-6 fatcat:vr2hdri55naf3psxrn5n2u6j3y