Alladi Ramakrishnan Hall

BRST v/s EPR in Maxwell

Ronak Soni

TIFR

It has been known for a while that entanglement shouldn't be calculated
after gauge-fixing, because gauge-fixing 'rearranges' degrees of freedom
in space. However, it is an open question whether accounting for the
entanglement of the BRST ghosts cancels this gauge-dependence. More
precisely, the question is: do two different states in the same
BRST-cohomology necessarily have the same entanglement? A piece of
evidence that the answer is yes is that the replica trick path integral is
gauge-invariant. We show, however, that the answer is no, and further that
this is completely compatible with the gauge-invariance of the replica
trick path integral. Finally, I discuss whether we can bound the
gauge-dependence in some way.