Non-autonomous semilinear evolution equations with almost sectorial operators

Inspired by the theory of semigroups of growth α, we construct an evolution process of growth α. The abstract theory is applied to study semilinear singular non-autonomous parabolic problems. We prove that, under natural assumptions, a reasonable concept of solution can be given to such semilinear singularly non-autonomous problems. Applications are considered to non-autonomous parabolic problems in space of H?lder continuous functions and to a parabolic problem in a domain with a one dimensional handle. Marcelo J. D. Nascimento: Research partially supported by FAPESP # 02/11855-2, Brazil.