The study of global solvability and hypoellipticity of differential operators on manifolds has attained increasing prominence over recent decades. At its core, global solvability investigates the ...

Transactions of the American Mathematical Society, Vol. 347, No. 10 (Oct., 1995), pp. 3671-3742 (72 pages) Results in the spectral theory of differential operators, and recent results on conformally ...

Sufficient conditions are given for the existence, uniqueness and finite-dimensional approximation of the solution to a first-order infinite-dimensional vector differential equation. Given a suitable ...