The Delta Institute for Theoretical Physics, or Delta ITP, originated over a decade ago as a long-term sustainable initiative for cooperation between the institutes for theoretical physics in Leiden, Utrecht, and Amsterdam. With the support of an NWO Gravitation grant in 2012, the Delta ITP consortium was elevated to a coherent, critical-mass, highest-quality, collaborative research environment, home to some of the highest-ranked and most talented theoretical physicists in the world. Focussing on groundbreaking as well as fundamental overarching themes, ranging from (quantum) materials to black holes and Big Bang cosmology, Delta ITP currently contains over 50 staff members, of which roughly 60 percent has been awarded an individual VIDI/VICI or ERC grant, and more than 120 temporary junior positions. Primary among the temporary positions are the jointly supervised PhD and postdoctoral positions with supervisors in at least two different institutes, as well as the prestigious Delta ITP fellowships. The latter applies to exceptional international talent that is actively scouted for, well-funded with ample means for travel, equipment, visitors, and workshops. By now the Delta Fellowship program has attracted more about a dozen of the most talented junior theoretical physicists that have moved on to become faculty members either in or beyond the Delta ITP triangle. Over the last decade, Delta ITP junior and senior members have been involved in some of the biggest developments in theoretical physics, ranging from the underpinnings of quantum gravity, holography and the primordial origin of our universe, to superconductivity, quantum information and computing.

Delta ITP has manifestly established itself as among the highest-quality and most attractive research centers in theoretical physics in the world. Through the NWO Gravitation funding as well as through its intrinsic open and collaborative nature, Delta ITP has benefitted the entire Dutch theoretical physics landscape, propelling it to the world stage. Since funding for theoretical physics is largely dependent on individual grants and open competition, the long-term Gravitation scheme has been pivotal to elevate the field of theoretical physics in the Netherlands. Since 2013 it hosted over 100 conferences, workshops, and an even larger number of visitors (both short- and long-term, from junior to senior), significantly contributing to its international impact and reputation.