The first instances of deformation theory were given by Kodaira and Spencer for complex structures and by Gerstenhaber for associative algebras. Since then, deformation theory has been applied as a useful tool in the study of many other mathematical structures, and even today it plays an important role in many developments of modern mathematics.This volume collects a few self-contained and peer-reviewed papers by experts which present up-to-date research topics in algebraic and motivic topology, quantum field theory, algebraic geometry, noncommutative geometry and the deformation theory of Poisson algebras. They originate from activities at the Max-Planck-Institute for Mathematics and the Hausdorff Center for Mathematics in Bonn.

Dr. Hossein Abbaspour, Department of Mathematics, Université de Nantes, France.Prof. Dr. Matilde Marcolli, Department of Mathematics, California Institute of Technology, Pasadena, California, USA.Dr. Thomas Tradler, Department of Mathematics, New York City College of Technology (CUNY), New York, USA.

On the Hochschild and Harrison (co)homology of C ?-algebras and applications to string topology.- What is the Jacobian of a Riemann Surface with Boundary?.- Pure weight perfect Modules on divisorial schemes.- Higher localized analytic indices and strict deformation quantization.- An algebraic proof of Bogomolov-Tian-Todorov theorem.- Quantizing deformation theory.- L ?-interpretation of a classification of deformations of Poisson structures in dimension three.