309 research outputs found
Pohozhaev and Morawetz Identities in Elastostatics and Elastodynamics
We construct identities of Pohozhaev type, in the context of elastostatics
and elastodynamics, by using the Noetherian approach. As an application, a
non-existence result for forced semi-linear isotropic and anisotropic elastic
systems is established
Differential Invariants of Conformal and Projective Surfaces
We show that, for both the conformal and projective groups, all the
differential invariants of a generic surface in three-dimensional space can be
written as combinations of the invariant derivatives of a single differential
invariant. The proof is based on the equivariant method of moving frames.Comment: This is a contribution to the Proceedings of the 2007 Midwest
Geometry Conference in honor of Thomas P. Branson, published in SIGMA
(Symmetry, Integrability and Geometry: Methods and Applications) at
http://www.emis.de/journals/SIGMA
On the Structure of Lie Pseudo-Groups
We compare and contrast two approaches to the structure theory for Lie
pseudo-groups, the first due to Cartan, and the second due to the first two
authors. We argue that the latter approach offers certain advantages from both
a theoretical and practical standpoint
Real Lie Algebras of Differential Operators and Quasi-Exactly Solvable Potentials
We first establish some general results connecting real and complex Lie
algebras of first-order differential operators. These are applied to completely
classify all finite-dimensional real Lie algebras of first-order differential
operators in . Furthermore, we find all algebras which are quasi-exactly
solvable, along with the associated finite-dimensional modules of analytic
functions. The resulting real Lie algebras are used to construct new
quasi-exactly solvable Schroedinger operators on .Comment: 33 pages, plain TeX. To apper in Phil. Trans. London Math. Soc.
Please typeset only the file rf.te
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