This book, first published in 2001, is a complete and coherent exposition of the theory and applications of torsors to rational points.

Torsors, also known as principal bundles or principal homogeneous spaces, are ubiquitous in mathematics. The purpose of this book is to present expository lectu

This book is motivated by the problem of determining the set of rational points on a variety, but its true goal is to equip readers with a broad range of tools

The section conjecture in anabelian geometry, announced by Grothendieck in 1983, is concerned with a description of the set of rational points of a hyperbolic a

Based on survey lectures given at the 2006 Clay Summer School on Arithmetic Geometry at the Mathematics Institute of the University of Gottingen, this tile is i