Isaac Chavel is Professor of Mathematics at The City College of the City University of New York. He received his Ph.D. in Mathematics from Yeshiva University under the direction of Professor Harry E. Rauch. He has published in international journals in the areas of differential geometry and partial differential equations, especially the Laplace and heat operators on Riemannian manifolds. His other books include Eigenvalues in Riemannian Geometry (1984) and Isoperimetric Inequalities: Differential Geometric and Analytic Perspectives (Cambridge University Press, 2001). He has been teaching at Th...