Recorded 10 March 2022. Matteo Gori of the University of Luxembourg presents "Field theory methods for multiscale description of quantum systems" at IPAM's Advancing Quantum Mechanics with Mathematics and Statistics Tutorials. Abstract: Quantum field theory has been originally conceived to provide a description of quantum systems consistent with special relativity that allows energy to be converted into mass (particles). Nowadays, fundamental interactions (except for gravity) are described in terms of quantum field theory. The attempt made by physicists to connect the microscopic scale of fundamental interactions with the physics observed at higher “macroscopic” scales revealed how field theories entail some general concepts appearing in the description of multiscale phenomena: order/disorder, symmetry breakdown, collective modes, correlations, macroscopic quantum phenomena just to mention some of them. In this course, a brief review of quantum field theories is presented. In particular, it will be shown how the existence of inequivalent Hilbert space representations in quantum field theory (a sharp difference to quantum mechanics) provides the natural conceptual framework to describe multiscale phenomena with applications to condensed matter physics and biology. Learn more online at: http://www.ipam.ucla.edu/programs/workshops/advancing-quantum-mechanics-with-mathematics-and-statistics-tutorials/?tab=schedule