# What is quantum field theory? A quantum information theorist’s perspective

### Monday, 01 Jun. 2015, 17:30 - 19:00

**Presenter:** Tobias Osborne

**Host:** Ivette Fuentes

**Where:** ATI, Lecture Hall, Stadionallee 2, Wien

There has been in a fruitful interplay of ideas between quantum information theory and high energy physics, especially in the context of quantum simulation, the AdS/CFT correspondence, and the black hole information loss paradox. However, a core difficulty faced by quantum information theorists – who are usually concerned with qubits – interested in these emergent and vibrant areas is the necessity of dealing with quantum fields. The primary purpose of this talk is to lower the entry barrier for quantum information theorists to work on these topics by explaining what, in a quantum information friendly way, a quantum field state actually is. I'll describe the Wilsonian formulation of quantum field theory as an effective theory and explain how this leads naturally to a definition, independent of lagrangians, of quantum field states which is better adapted to, e.g., tensor networks. We hope that there is something here for high-energy theorists as well, if only to see how someone from “the other side” thinks about complex quantum systems.