# Perspectives on Information Causality

Tony Short ( Research Fellow at the Department of Applied Mathematics and Theoretical Physics, University of Cambridge )

- 14:00 18th November 2011 ( week 6, Michaelmas Term 2011 )380

The information causality principle [1] is a generalisation

of the no-signalling principle which is obeyed by quantum and

classical physics, but which rules out many other theories. In this

talk, I will present two new perspectives on information causality

[2]: a probabilistic analysis yielding simple quadratic bounds on the

set of quantum correlations, and an entropic analysis suggesting that

the ability to define a `good' measure of entropy in quantum theory is

one of its defining features.

[1] M. Pawlowski et al., Nature 461, 1101 (2009).

[2] S.W. Al-Safi and A.J. Short, PRA 84, 042323 (2011).