ICTIR is the premier conference of theoretical information retrieval (IR), covering a broad spectrum of diverse research areas that are concerned with mathematical/formal aspects of IR, including foundational issues, description or integration of models, retrieval applications, mathematical/formal techniques, existing and/or new theories and theoretical aspects. There are exciting new developments in ICTIR13: the conference program includes four tutorials open to all participants, a lively panel discussion on the challenges and long range opportunities for IR research and three exciting keynotes from Keith van Rijsbergen, Ricardo Baeza-Yates and Dominic Widdows. On behalf of the organising committee, we invite you to join us in Copenhagen for ICTIR13!