Explicit formulas for the 3-jet lift of a matrix group. Applications to conformal geometry

Abstract

Jet lifts of groups of matrices enter into play when one studies the problem of integrability of G-structures as it was posed by V. Guillemin in his seminal work [Trans. Amer. Math. Soc. 116 (1965), 544–560;]. The authors of the present paper analyze carefully the case of 3-jet lifts. Their first result is that G3 is isomorphic to a semidirect product of G itself and a nilpotent group constructed from the first two prolongations of its Lie algebra. This result permits them to discuss several natural representations of G3 . An application to the case of the conformal group is given