In its simplest form, Hodge theory is the study of periods – integrals of algebraic differential forms which arise in the study of complex geometry and moduli, number theory and physics. Organized around the basic concepts of variations of Hodge structure and period maps, this volume draws together new developments in deformation theory, mirror symmetry, Galois representations, iterated integrals, algebraic cycles and the Hodge conjecture. Its mixture of high-quality expository and research articles make it a useful resource for graduate students and seasoned researchers alike. Combines cutting-edge research and expository articles in Hodge theory. An essential reference for graduate students and researchers. Matt Kerr is an Associate Professor of Mathematics at Washington University, St Louis, and an established researcher in Hodge theory and algebraic geometry. His work is supported by an FRG grant from the National Science Foundation. He is also co-author (with M. Green and P. Griffiths) of Mumford-Tate Groups and Domains: Their Geometry and Arithmetic and Hodge Theory, Complex Geometry, and Representation Theory. Gregory Pearlstein is an Associate Professor of Mathematics at Texas A&M University. He is an established researcher in Hodge theory and algebraic geometry and his work is supported by an FRG grant from the National Science Foundation.