Q+ hangouts is a series of online seminars on quantum foundations and quantum information that take place on Google+ using the hangouts feature. The next talk is on quantum foundations, so it may be of interest to subscribers of this list.
Date/time: Tuesday 23rd October 2pm BST
Speaker: Markus Mueller (Perimeter Institute)
Title: Three-dimensionality of space and the quantum bit: an information-theoretic approach
Absract: It is sometimes pointed out as a curiosity that the state space of quantum two-level systems, i.e. the qubit, and actual physical space are both three-dimensional and Euclidean. In this talk, I report on joint work with Lluis Masanes, where we attempt an information-theoretic analysis of this relationship, by proving a particular mathematical result: suppose that physics takes place in d spatial dimensions, and that some events happen probabilistically (not assuming quantum theory in any way). Furthermore, suppose there are systems that behave in some sense as “units of direction information”, interacting via some continuous reversible time evolution. We prove that this uniquely determines spatial dimension d=3 and quantum theory on two qubits. Hence, abstractly postulating the “nice” behavior of a Stern-Gerlach device in information-theoretic terms determines already some important aspects of physics as we know it.