Second-order differential invariants of the rotation group O(n) and of its extensions: E(n), P(1,n), G(1,n)

Abstract

Functional bases of second-order differential invariants of the Euclid, Poincaré, Galilei, conformal, and projective algebras are constructed. The results obtained allow us to describe new classes of nonlinear many-dimensional invariant equations.

arXiv comment19 pages; some misprints of the journal article are corrected