Semi-Riemannian Geometry With Applications to…
This book is an exposition of semi-Riemannian geometry (also called pseudo-Riemannian geometry)--the study of a smooth manifold furnished with a metric tensor of arbitrary signature. The principal special cases are Riemannian geometry, where the metric is positive definite, and Lorentz geometry. For many years these two geometries have developed almost independently: Riemannian geometry reformulated in coordinate-free fashion and directed toward global problems, Lorentz geometry in classical tensor notation devoted to general relativity., More recently, this divergence has been reversed as physicists, turning increasingly toward invariant methods, have produced results of compelling mathematical interest.
from O'Neill, BarrettCompare price
Mathematical Origami: Geometrical Shapes by…
Origami is the art of paper folding without the use of either scissors or glue. Each of the beautiful and fundamental math shapes described in this book is achieved by folding sheets of standard A4 paper. There are step-by-step instructions for each of the shapes in this very impressive collection.
from Mitchell, DavidCompare price