BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Pablo Bueno (Centro Atomico Bariloche (Argentina)) DTSTART:20200611T140000Z DTEND:20200611T150000Z DTSTAMP:20260423T003300Z UID:IFTWeb/3 DESCRIPTION:Title: R eflected entropy\, symmetries and free fermions\nby Pablo Bueno (Centr o Atomico Bariloche (Argentina)) as part of IFT-Madrid Webinars\n\n\nAbstr act\nEntanglement entropy (EE) is an intrinsically divergent quantity in q uantum field theory (QFT). Recently\, a well-defined notion of von Neumann entropy associated to pairs of spatial subregions has been proposed both in the holographic context — where it has been argued to be related to t he entanglement wedge cross section — and for general QFTs. I will show that\, similarly to the EE\, the reflected entropy for Gaussian fermion sy stems can be simply obtained in terms of correlation functions and I will explicitly evaluate it numerically for two intervals in the case of a two- dimensional Dirac field. Then\, I will argue that the definition of this “reflected entropy” can be canonically generalized in a way which is p articularly suitable for orbifold theories — those obtained by restricti ng the full algebra of operators to those which are neutral under a global symmetry group. I will evaluate explicitly this new "type-I entropy” fo r the $\\mathbb{Z}_2$ bosonic subalgebra of the Dirac field. A key role in the construction is played by type-I von Neumann algebras\, which differ from the usual type-III algebras associated to spatial regions in QFT. Usi ng the free-fermions case\, I will perform very explicit comparisons betwe en both types of algebras.\n\nEmail iftweb101@gmail.com to get zoom link \n LOCATION:https://researchseminars.org/talk/IFTWeb/3/ END:VEVENT END:VCALENDAR