This book includes papers presented at the Young Researchers Symposium of the 14th International Congress on Mathematical Physics, held in July 2003, in Lisbon, Portugal. The goal of thes book is to illustrate various promising areas of mathematical physics in a way accessible to researchers at the beginning of their career. Two of the three laureates of the Henri Poincare Prizes, Huzihiro Araki and Elliott Lieb, also contributed to this volume. The book provides a good survey of some active areas of research in modern mathematical physics.