Estimates for singular integral operators (Q934523)

For certain classes of kernels leading to singular integral operators of the type \[ \text{p.v.}\,\int^\infty_0 K(r,t)\varphi(t)\,dt, \] the singularity is at \(t= -r\), the authors obtain some estimates. Their main purpose is to bring some techniques due to \textit{A.\,Beurling} [Duke Math.\ J.\ 16, 355--359 (1949; Zbl 0033.36503)] to work in a new situation.