BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Kiryl Pakrouski (Princeton University) DTSTART:20200724T174500Z DTEND:20200724T190000Z DTSTAMP:20260422T230721Z UID:IAS_HighEnergyTheory_Friday/1 DESCRIPTION:Title: Many body scars as a group invariant sector of Hilbert space\nby Kiryl Pakrouski (Princeton University) as part of IAS High Energy Theory Friday Seminars\n\n\nAbstract\nWe present a class of Hamilto nians H for which a sector of the Hilbert space invariant under a Lie grou p G\, which is not a symmetry of H\, possesses the essential properties of many-body scar states. These include the absence of thermalization and th e non-decaying “revivals” of special initial states in time evolution . Some of the scar states found in earlier work may be viewed as special c ases of our construction. A particular class of examples concerns interact ing spin-1/2 fermions on a lattice consisting of N sites (Fermi-Hubbard mo del as a special case)\, and we show that it contains two families of N+1 scar states. One of these families\, which was found in recent literature\ , is comprised of the well-known eta-pairing states that have been linked to superconductivity. We find another family of scar states which is U(N) invariant.\n\nBoth families and most of the group-invariant scar states pr oduced by our construction in general\, give rise to the off-diagonal long range order which survives at high temperatures and is insensitive to the details of the dynamics. Such states could be used for reliable quantum i nformation processing because the information is stored non-locally\, and thus cannot be easily erased by local perturbations. This talk will be bas ed on arXiv:2007.00845.\n LOCATION:https://researchseminars.org/talk/IAS_HighEnergyTheory_Friday/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Lorenz Eberhardt (Institute for Advanced Study) DTSTART:20200828T174500Z DTEND:20200828T190000Z DTSTAMP:20260422T230721Z UID:IAS_HighEnergyTheory_Friday/2 DESCRIPTION:Title: Partition functions of the tensionless string\nby Lorenz Eberhardt (Institute for Advanced Study) as part of IAS High Energy Theory Friday Seminars\n\n\nAbstract\nI discuss string theory on AdS3xS3x T4 in the tensionless limit\, with one unit of NS-NS flux. This theory is conjectured to be dual to the symmetric product orbifold CFT. I show how t o compute the full string partition function on various locally AdS3 backg rounds\, such as thermal AdS3\, the BTZ black and conical defects\, and fi nd that it is independent of the actual background\, but only depends on t he boundary geometry. Consequently\, reproducing the boundary partition fu nction does not require a sum over bulk geometries\, but rather agrees wit h the string partition function on any bulk geometry with the appropriate boundary. I argue that the same mechanism shows the factorization of the b ulk partition function when geometries with disconnected boundaries are co nsidered.\n LOCATION:https://researchseminars.org/talk/IAS_HighEnergyTheory_Friday/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Aidan Herderschee (Institute for Advanced Study) DTSTART:20230915T150000Z DTEND:20230915T160000Z DTSTAMP:20260422T230721Z UID:IAS_HighEnergyTheory_Friday/3 DESCRIPTION:Title: The Next-to-Leading Order Scattering Waveform from Amp litudes\nby Aidan Herderschee (Institute for Advanced Study) as part o f IAS High Energy Theory Friday Seminars\n\n\nAbstract\nI will showcase th e computation of the next-to-leading order scattering waveform in classica l gravity using amplitude techniques. I will first give an overview of how to compute generic classical observables in gravity using scattering ampl itude techniques in the KMOC formalism. In particular\, I will focus on ho w classical physics systematically emerges from quantum amplitudes and how calculations simplify in the classical limit. I will then sketch the comp utation of the sub-leading contribution to the classical waveform\, an out -of-time-order observable which roughly corresponds to the 1-loop 5-point amplitude. I will conclude with a discussion of different aspects of the w aveform\, such as the memory effect and an IR divergent phase\, along with future directions.\n LOCATION:https://researchseminars.org/talk/IAS_HighEnergyTheory_Friday/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Michael Borinsky (ETH Zurich) DTSTART:20231006T150000Z DTEND:20231006T160000Z DTSTAMP:20260422T230721Z UID:IAS_HighEnergyTheory_Friday/4 DESCRIPTION:Title: The Dark-Matter Problem of the Moduli Space of Curves and its (partial) Tropical Solution\nby Michael Borinsky (ETH Zurich) as part of IAS High Energy Theory Friday Seminars\n\n\nAbstract\nThe modul i space of curves\, M_g\, is an object of pivotal interest in mathematics and theoretical physics. Even though it has been studied with tremendous e ffort\, little is known about its topology. For instance\, the total dimen sion of the cohomology of M_g grows quickly with g\, but the known constru ctions for cohomology classes only account for a negligibly small part of this growth. The known existence of huge amounts of cohomology and the lac k of explanation for it\, is dubbed the 'dark-matter problem' of M_g. In t his talk\, I will review the state-of-the-art and a recent breakthrough by Chan-Galatius-Payne who used a tropicalization of the moduli space of cur ves to construct a new source of cohomology in M_g which quickly drafts al l previously known sources. Eventually\, I will present new results which show that this new source still only accounts for a small part of the tot al cohomology. The proof makes use of QFT inspired path-integrals.\n LOCATION:https://researchseminars.org/talk/IAS_HighEnergyTheory_Friday/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Nikita Sopenko (Institute for Advanced Study) DTSTART:20231020T150000Z DTEND:20231020T160000Z DTSTAMP:20260422T230721Z UID:IAS_HighEnergyTheory_Friday/5 DESCRIPTION:Title: Equivariant Higher Berry Classes for Quantum Many-Body Systems\nby Nikita Sopenko (Institute for Advanced Study) as part of IAS High Energy Theory Friday Seminars\n\n\nAbstract\nI will talk about th e invariants of topologically ordered states of quantum lattice systems th at generalize Berry classes and can be defined for any gapped state in any dimension. The equivariant version of such invariants unifies and general izes the Hall conductance and the Thouless pump. I will also discuss the c onstruction of 2d chiral states for which these invariants can be computed exactly providing evidence that these states realize topological order as sociated with an arbitrary unitary rational vertex operator algebra.\n LOCATION:https://researchseminars.org/talk/IAS_HighEnergyTheory_Friday/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Qianshu Lu (Institute for Advanced Study) DTSTART:20231208T160000Z DTEND:20231208T170000Z DTSTAMP:20260422T230721Z UID:IAS_HighEnergyTheory_Friday/6 DESCRIPTION:by Qianshu Lu (Institute for Advanced Study) as part of IAS Hi gh Energy Theory Friday Seminars\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/IAS_HighEnergyTheory_Friday/6/ END:VEVENT END:VCALENDAR