We study initial boundary value problems for linear evolution partial differential equations (PDEs) posed on a time-dependent interval
,
, where
and
are given, real, differentiable functions, and
T is an arbitrary constant. For such problems, we show how to characterise the unknown boundary values in terms of the given initial and boundary conditions.
... [Show full abstract] As illustrative examples we consider the heat equation and the linear Schr\"{o}dinger equation. In the first case, the unknown Neumann boundary values are expressed in terms of the Dirichlet boundary values and of the initial value through the unique solution of a system of two linear integral equations with explicit kernels. In the second case, a similar result can be proved but only for a more restrictive class of boundary curves.}