Tuesday, August 30, 2005

Entanglement entropy

One of the most interesting papers 24 hours ago was a paper by three authors from Santa Barbara, Israel, and Michigan claiming that the black hole entropy in all known examples in string theory may be entirely interpreted as

It is certainly true that not everyone has believed and believes that the whole entropy equals the entanglement entropy; others viewed entanglement entropy merely as one of the contributions. The total number of microstates of the interior counts the total entropy; but it is not necessarily true that each of them is entangled with a different state of the exterior degrees of freedom. The entanglement entropy could therefore be smaller. I am curious to hear comments from others.

Also,

offers a new proof of the CSW rules for the tree amplitudes based on the maximally helicity violating vertices. If someone can explain in what sense the proof is more direct than the BCFW proof, it may be interesting.