Week 30.11.2014 – 06.12.2014

It will be shown that the dynamics of discrete (integer-valued) Hamiltonian cellular automata can only be consistently defined, if it is linear in the same sense that unitary evolution in quantum mechanics is linear. This suggests us to look for an invertible map between such automata and continuous quantum mechanical models. Based on sampling theory, such a map can indeed be constructed and leads to quantum mechanical models which incorporate a fundamental scale. The admissible observables, the one-to-one correspondence of the respective conservation laws, and the existence of solutions of the modified dispersion relation for stationary states are discussed. References: H.-T. Elze, Action principle for cellular automata and the linearity of quantum mechanics, Phys. Rev. A 89, 012111 (2014) [arXiv:1312.1615]; do., Journal of Physics: Conference Series 504 (2014) 012004 [arXiv:1403.2646];

In my talk I will give a brief review on entanglement entropy and discuss some recent developments which include relations to the geometric Willmore conjecture and the role of total derivatives in the trace anomaly.

Motivated by either condensed matter or quantum gravity holographic considerations, I will discuss some preliminary work on how to compute the time evolution in Renyi entropies in 2d CFTs in the large c limit for thermal states perturbed by localized primary operators. Time permitting, I will comment on the potential relation between this work and previous holographic calculations in the context of the EPR=ER conjecture.