Title: Quantum physics and graph colouring,

Speaker: Reza Naserasr

Date: Friday November 30th, 10:00 AM.
Location: HP-4351 Carleton university

Abstract. Given a vector space $V=F^n$ we define orthogonality graph on $V$,
denoted $O(V)$, to be a graph whose vertices are one dimensional subspaces of $V$,
two vertices being adjacent if and only if they are orthogonal. It is a fundamental theorem
in quantum physics that no independent set of $O(R^3)$ covers all the triangles of it.
This, in particular, implies that $O(R^3)$ is 4-chromatic. In this talk I will first show the
importance of this theorem in quantum physics, then motivated by this theorem will show
some results about other chromatic parameters of $O(R^3)$.

This is a joint work with M. DeVos, M. Ghebleh, L. Godyn and B. Mohar.