International Journal of Mathematics and Mathematical Sciences
Volume 1 (1978), Issue 1, Pages 137-140
doi:10.1155/S0161171278000174

Maps of manifolds with indefinite metrics preserving certain geometrical entities

R.S. Kulkarni

Department of Mathematics, Indiana University, Bloomington 47401, Indiana, USA

Abstract

It is shown that (i) a diffeomorphism of manifolds with indefinite metrics preserving degenerate r-plane sections is conformal, (ii) a sectional curvature-preservlng diffeomorphism of manifolds with indefinite metrics of dimension 4 is generically an isometry.