BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Pablo Bueno (Instituto Balseiro\, Bariloche) DTSTART:20201021T190000Z DTEND:20201021T201500Z DTSTAMP:20260404T143402Z UID:IFQ/7 DESCRIPTION:Title: Reflected entropy\, free fields and symmetries\nby Pablo Bueno (Ins tituto Balseiro\, Bariloche) as part of It from Qubit\n\n\nAbstract\nA wel l-defined notion of von Neumann entropy associated to pairs of spatial sub regions has been recently proposed both in the holographic context and for general QFTs. I will show that in the case of Gaussian systems ---and sim ilarly to the entanglement entropy (EE)--- this "reflected entropy” can be obtained in terms of correlation functions of the fields. In particular \, I will present general formulas valid for free scalars and fermions in arbitrary dimensions. I will apply the results to various free theories in 1+1 and 2+1 dimensions\, verifying that the conjectural monotonicity prop erty $R(A\,BC)\\geq R(A\,B)$ and the general inequality $R(A\,B)\\geq I(A\ ,B)$ hold in all cases. The results obtained suggest that for general regi ons characterized by length-scales $L_A\\sim L_B \\sim L$ and separated a distance $\\ell$\, the reflected entropy in the large-separation regime ($ x\\equiv L/\\ell \\ll 1$) is related to the mutual information by: $R(x) \ \sim −I(x) \\log x$ for general CFTs in arbitrary dimensions. Finally\, I will argue that the notion of reflected entropy can be canonically gene ralized in a way which is particularly suitable for theories obtained by r estricting the full algebra of operators to those which are neutral under global symmetry groups. A key role in the discussion is played by type-I v on Neumann algebras\, which differ from the usual type-III algebras associ ated to spatial subregions in QFT. I will perform various explicit compari sons between both types of algebras.\n LOCATION:https://stable.researchseminars.org/talk/IFQ/7/ END:VEVENT END:VCALENDAR