James Carlson is Professor Emeritus at the University of Utah. From 2003 to 2012, he was president of the Clay Mathematics Institute, New Hampshire. Most of Carlson's research is in the area of Hodge theory. Stefan Müller-Stach is Professor of number theory at Johannes Gutenberg Universität Mainz, Germany. He works in arithmetic and algebraic geometry, focussing on algebraic cycles and Hodge theory, and his recent research interests include period integrals and the history and foundations of mathematics. Recently, he has published monographs on number theory (with J. Piontkowski) and period numbers (with A. Huber), as well as an edition of some works of Richard Dedekind. Chris Peters is a retired professor from the Université Grenoble Alpes, France and has a research position at the Eindhoven University of Technology, The Netherlands. He is widely known for the monographs Compact Complex Surfaces (with W. Barth, K. Hulek and A. van de Ven, 1984), as well as Mixed Hodge Structures, (with J. Steenbrink, 2008). He has also written shorter treatises on the motivic aspects of Hodge theory, on motives (with J. P. Murre and J. Nagel) and on applications of Hodge theory in mirror symmetry (with Bertin).