Prof. Nissan Itzhaki works on string theory, field theory, gravity and cosmology. Quantum Field Theory joins together quantum mechanics with the theory of special relativity, and it is the main framework used to study problems in particle physics, and many problems in condensed matter physics. Traditionally this framework starts from a given theory at short distance scales, and uses this to study the physics at larger distances, which can be experimentally measured. Recently it was realized that in some cases one can go in the opposite direction, starting from a long distance theory and deriving in it some short distance physics, that can be different than the standard one of quantum field theories. This leads to many conceptual as well as technical questions that were addressed in the last few years. These questions are likely to affect our understanding of topics ranging from black hole physics to condensed matter physics. At least in the near future he intends to keep on exploring this fascinating direction.