Dear all, Laura Burri's bachelor thesis presentation will take place today at 4:00pm in the UZH Irchel campus, room Y36K08

. It will be a 25min talk followed by questions. Title and abstract below.    Hilbert space factorisation and locality
 In quantum mechanics, the tensor product rule allows one to describe independent systems jointly. However, if one is given a global system, there is a priori no reason for considering some factorization of the system’s state space as “the only physical one”. Thus, if multiple agents observe the same system, their implicit assumptions on how the state space factors do not necessarily coincide. Is it possible to derive from the agents’ perspectives how their implicitly assumed factorizations are related? The problem of answering this question is what we call The Factorization Problem as it pays attention to the various possible factorizations of the same Hilbert space. The aim of solving the factorization problem is to derive from agents’ abilities how their objects of observation are related, rather than assume from the outset knowledge about this relation. In this work I motivate and define the factorization problem. Furthermore, I introduce a classification of how two agents’ assumptions about the factorization of some system’s state space can be related. For some of these classes, conditions have been found which are fundamental for solving the factorization problem. Yet, no generic solution of the factorization problem exists. Best, Lídia