This volume covers the proceedings of a special session "Recent advances in
Riemannian and Lorentzian geometries" of the annual meeting of American Math-
ematical Society, held at Baltimore, January 15-18, 2003. The speakers presented
their research on Riemannian, Lorentzian, and pseudo-Riemannian manifolds.
The topics covered include classification of curvature-related operators, curva-
ture-homogeneous Einstein 4-manifolds, linear stability /instability, singularity and
hyperbolic operators of spacetimes, spectral geometry, cut loci of nilpotent Lie
groups, conformal geometry of almost Hermitian manifolds and also submanifolds
of complex and contact submanifolds.
This special session presented a great setting for differential geometers to inter-
act among themselves and to expose the interplay/ exchange between Riemannian
and Lorentzian geometries. All the topics published in this volume were formally
We are grateful to the American Mathematical Society for the support in pub-
lishing this volume. Also thanks to all the participants and the contributors for
their interest and work in publication of these proceedings.