Covariant Non-Commutative Spacetime

Dr Jonathan Heckman
Harvard University

14 March 2013 (Thursday)
3:00 - 4:00 pm
Room 4612 (4/F via Lifts 31-32), HKUST

Abstract:

In quantum mechanics, the commutator [x , p] = i hbar reflects an inability to simultaneously know the position and momentum of a particle to arbitrary accuracy. But What happens if the coordinates of spacetime no longer commute? This initially looks like an attractive way to introduce a minimal length scale for spacetime, and thus as a potential starting point for addressing issues in quantum gravity. However, it comes at a steep price: The loss of Lorentz invariance. In this talk, the speaker revisits this question, showing that for spacetimes with a non-zero cosmological constant such as de Sitter space, a Lorentz invariant non-commutative deformation exists. He argues that spacetime physics is best understood as a string theory in which observers communicate via string exchange.