Integral formulas related to wave fronts
Volume 50 / 1999
Banach Center Publications 50 (1999), 11-17
DOI: 10.4064/-50-1-11-17
Abstract
In the first section of the paper we study some properties of oriented volumes of wave fronts propagating in spaces of constant curvature. In the second section, we generalize to an arbitrary isometric action of a Lie group on a Riemannian manifold the following principle: an extra pression inside of a ball does not move it.
