Linear evolution equations with strongly measurable families and application to the Dirac equation
Let \(\{A(t)\}\) be a family of closed linear operators in a separable Hilbert space \(X\), and \(S\) a selfadjoint operator in \(X\) satisfying \[ (u, Su)\geq \|u\|^2 \quad \text{for all } u\in D(S). \] Under some conditions associated with \(\{A(t)\}\) and \(S\), the authors, by a modified Yosida approximation, construct a two-parameter family \(\{U(t,s): 0\leq s\leq t\leq T\}\) satisfying certain properties. Applications to the Dirac equation are given.
scientific article; zbMATH DE number 5869377