The contributions in this book explore various contexts in which the derived category of coherent sheaves on a variety determines some of its arithmetic. This setting provides new geometric tools for interpreting elements of the Brauer group. With a view towards future arithmetic applications, the book extends a number of powerful tools for analyzing rational points on elliptic curves, e.g., isogenies among curves, torsion points, modular curves, and the resulting descent techniques, as well as higher-dimensional varieties like K3 surfaces. Inspired by the rapid recent advances in our understanding of K3 surfaces, the book is intended to foster cross-pollination between the fields of complex algebraic geometry and number theory. Contributors:· Nicolas Addington· Benjamin Antieau· Kenneth Ascher · Asher Auel· Fedor Bogomolov· Jean-Louis Colliot-Thélène· Krishna Dasaratha· Brendan Hassett· Colin Ingalls· Martí Lahoz· Emanuele Macrì· Kelly McKinnie· Andrew Obus· Ekin Ozman· Raman Parimala· Alexander Perry· Alena Pirutka· Justin Sawon· Alexei N. Skorobogatov· Paolo Stellari· Sho Tanimoto· Hugh Thomas· Yuri Tschinkel· Anthony Várilly-Alvarado· Bianca Viray· Rong Zhou