Search Talks

I will introduce Kitaev's suface codes as a block quantum error-correcting code. Recovery procedures will be described in the case of imperfect syndrome measurements. More might be covered if time permits.

ABSTRACT: The asymptotic freedom conjecture for gravitation is explored in which strong renormalization effects (as in QCD) may occur at astrophysical distance scales larger than the solar system. Nonperturbative renormalization group trajectories exhibiting such an infrared fixed point describe a theory of gravitation with a running gravitational coupling which grows at large distance. The concept that this extra gravity may provide the answer to the missing mass inherent in the dark matter paradigm is a natural suggestion. We provide the alternative of Modified Gravity to answer the problem of galaxy rotation curves from the smallest dwarf galaxies to the largest giant galaxies and to galaxy clusters including the Bullet Cluster. The theory may also explain the apparent anomalous deceleration of the Pioneer 10 and 11 space probes, within solar system constraints.

The entanglement entropy between quantum fields inside and outside a black hole horizon is a promising candidate for the microscopic origin of black hole entropy. I will explain the motivation behind this interpretation of black hole entropy, and why it requires quantum gravity. I will then apply these ideas to loop quantum gravity and show how to compute the entanglement entropy of spin network states. The result of this calculation agrees asymptotically with results from the isolated horizon framework, and I will give the reason for this agreement. Finally, I will show that the entanglement entropy gives extensive corrections to the area law, suggesting corrections to the gravitational action.