Lorentz invariant distributions supported on the forward light cone Johan A. C. Kolk; V. S. Varadarajan — 1992 Compositio Mathematica
Functions, flows and oscillatory integrals on flag manifolds and conjugacy classes in real semisimple Lie groups J. J. Duistermaat; J. A. C. Kolk; V. S. Varadarajan — 1983 Compositio Mathematica