|
Georgian Mathematical Journal 09 (2002), No. 4, 723--774 Copyright Heldermann Verlag 2002 Differential Equations, Spencer Cohomology, and Computing Resolutions Larry A. Lambe Mathematics Division, School of Informatics, University of Wales, Bangor, Gwynedd LL57 1UT, Great Britain Werner M. Seiler Lehrstuhl f. Mathematik I, Universitaet Mannheim, 68131 Mannheim, Germany We propose a new point of view of the Spencer cohomology appearing in the formal theory of differential equations based on a dual approach via comodules. It allows us to relate the Spencer cohomology with standard constructions in homological algebra and, in particular, to express it as a Cotor. We discuss concrete methods for its construction based on homological perturbation theory. Keywords: Partial differential equation, Spencer cohomology, formal theory, homological resolution, comodules, cobar construction, symbolic computation. MSC: 12Y05, 18G10, 18G15, 18G35, 18G60, 35G20, 35N99, 57T30, 68W30 [ Fulltext-pdf (428 KB)] |