%0 Journal Article %1 Casini2009Remarks %A Casini, H. %A Huerta, M. %D 2009 %I IOP Publishing %J Journal of High Energy Physics %K entanglement %N 03 %P 048 %R 10.1088/1126-6708/2009/03/048 %T Remarks on the entanglement entropy for disconnected regions %U http://dx.doi.org/10.1088/1126-6708/2009/03/048 %V 2009 %X Few facts are known about the entanglement entropy for disconnected regions in quantum field theory. We study here the property of extensivity of the mutual information, which holds for free massless fermions in two dimensions. We uncover the structure of the entropy function in the extensive case, and find an interesting connection with the renormalization group irreversibility. The solution is a function on space-time regions which complies with all the known requirements a relativistic entropy function has to satisfy. We show that the holographic ansatz of Ryu and Takayanagi, the free scalar and Dirac fields in dimensions greater than two, and the massive free fields in two dimensions all fail to be exactly extensive, disproving recent conjectures.

@article{Casini2009Remarks, abstract = {{Few facts are known about the entanglement entropy for disconnected regions in quantum field theory. We study here the property of extensivity of the mutual information, which holds for free massless fermions in two dimensions. We uncover the structure of the entropy function in the extensive case, and find an interesting connection with the renormalization group irreversibility. The solution is a function on space-time regions which complies with all the known requirements a relativistic entropy function has to satisfy. We show that the holographic ansatz of Ryu and Takayanagi, the free scalar and Dirac fields in dimensions greater than two, and the massive free fields in two dimensions all fail to be exactly extensive, disproving recent conjectures.}}, added-at = {2019-02-26T10:37:35.000+0100}, archiveprefix = {arXiv}, author = {Casini, H. and Huerta, M.}, biburl = {https://www.bibsonomy.org/bibtex/2a6965232c97b8eb710e528ae1457c0ff/acastro}, citeulike-article-id = {4153197}, citeulike-linkout-0 = {http://arxiv.org/abs/0812.1773}, citeulike-linkout-1 = {http://arxiv.org/pdf/0812.1773}, citeulike-linkout-2 = {http://dx.doi.org/10.1088/1126-6708/2009/03/048}, day = 17, doi = {10.1088/1126-6708/2009/03/048}, eprint = {0812.1773}, interhash = {8716e9800eb6acb81b589913f8121c66}, intrahash = {a6965232c97b8eb710e528ae1457c0ff}, issn = {1029-8479}, journal = {Journal of High Energy Physics}, keywords = {entanglement}, month = sep, number = 03, pages = 048, posted-at = {2012-11-13 19:24:00}, priority = {2}, publisher = {IOP Publishing}, timestamp = {2019-02-26T10:37:35.000+0100}, title = {{Remarks on the entanglement entropy for disconnected regions}}, url = {http://dx.doi.org/10.1088/1126-6708/2009/03/048}, volume = 2009, year = 2009 }