BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Thomas Dumistrescu (UCLA) DTSTART:20200506T191500Z DTEND:20200506T204500Z DTSTAMP:20260422T225926Z UID:USC-HET/1 DESCRIPTION:Title: An Introduction to 2-Group Global Symmetry\nby Thomas Dumistrescu (UCL A) as part of USC High Energy Theory Seminars\n\nLecture held in Online on ly\, but normally: SSC 319 on University Park Campus (USC).\n\nAbstract\nI will briefly review the generalization of ordinary global symmetries to h igher-form symmetries (which act on extended objects) in quantum field the ory. I will then showcase simple but surprising examples in 4d and 6d wher e ordinary and 1-form global symmetries are necessarily fused together int o a higher structure known as a 2-group. Time permitting\, I will discuss some applications to superconformal theories in 6d.\n\nZoom Meeting ID: 92 4 6768 3111\nPassword: 620110\n(You will enter a waiting room for a brief period.)\n LOCATION:https://researchseminars.org/talk/USC-HET/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Ibou Bah (Johns Hopkins U.) DTSTART:20200520T191500Z DTEND:20200520T204500Z DTSTAMP:20260422T225926Z UID:USC-HET/2 DESCRIPTION:Title: Anomaly Inflow and Geometric Engineering of Quantum Field Theory\nby I bou Bah (Johns Hopkins U.) as part of USC High Energy Theory Seminars\n\nL ecture held in SSC 319 on University Park Campus (USC).\n\nAbstract\nTitle : Anomaly Inflow and Geometric Engineering of Quantum Field Theory\n\nAbst ract: In this talk\, I will review recent results in using string theory t o compute anomalies of quantum fields theories. In particular\, I will de scribe reductions of anomaly polynomials in type IIB string theory and M-t heory on compact spaces to capture the anomalies for quantum field theorie s that describe the low-energy dynamics of branes in various configuration s. As examples of these methods\, I will describe how to obtain the anoma lies of quantum field theories in the reduction of SCFTs in 6d and 4d on p unctured Riemann surfaces. Another interesting example that will be discu ssed is the theory of M5-branes probing a Z_2 orbifold fixed point while w rapping Riemann surfaces. The anomaly inflow analysis in this latter examp le lead to the identification of its holographic duals.\n\nZoom Meeting ID : 927 1418 2739\nPassword: 861608\nYou will enter a waiting room for a sho rt while.\n LOCATION:https://researchseminars.org/talk/USC-HET/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Christoph Uhlemann (U. Michigan) DTSTART:20200422T191500Z DTEND:20200422T204500Z DTSTAMP:20260422T225926Z UID:USC-HET/3 DESCRIPTION:Title: Wilson loops in 5d long quiver gauge theories\nby Christoph Uhlemann ( U. Michigan) as part of USC High Energy Theory Seminars\n\nLecture held in SSC 319 on University Park Campus (USC).\n\nAbstract\nQuiver gauge theori es with a large number of nodes host a rich spectrum of line operators\, i ncluding Wilson loops associated with each individual gauge node. Exact re sults are discussed for Wilson loops in fundamental and k-fold antisymmetr ic representations\, for a sample of 5d long quiver gauge theories whose U V fixed points have holographic duals in Type IIB. The holographic represe ntation of the Wilson loops is identified\, and yields interesting insight s into the holographic duals.\n\nhttps://usc.zoom.us/j/98353393583\n\nMeet ing ID: 983 5339 3583\nPassword: 186449\n\nYou will enter a waiting room f or a short while.\n LOCATION:https://researchseminars.org/talk/USC-HET/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Felipe Rosso (USC) DTSTART:20200527T191500Z DTEND:20200527T204500Z DTSTAMP:20260422T225926Z UID:USC-HET/4 DESCRIPTION:Title: Achronal Averaged Null Energy Condition for extremal horizons and (A)dS\nby Felipe Rosso (USC) as part of USC High Energy Theory Seminars\n\n\nA bstract\nThe achronal Averaged Null Energy Condition (ANEC) is a conjectur ed bound on the stress tensor in semi-classical gravity that has deep impl ications for both gravitational and quantum theories. While several argume nts have been given in favor of this condition\, concrete and general proo fs are so far only available in Minkowski. In this talk I explain how the achronal ANEC can be explicitly derived using quantum information theory f or general QFTs in the near horizon of extremal black holes\, de Sitter an d anti-de Sitter.\n\nZoom meeting ID: 925 2872 4339\nPassword: 579212\n\n( You will enter a waiting room for a short while.)\n LOCATION:https://researchseminars.org/talk/USC-HET/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Luca Iliesiu (Princeton University) DTSTART:20201020T170000Z DTEND:20201020T181500Z DTSTAMP:20260422T225926Z UID:USC-HET/5 DESCRIPTION:Title: The statistical mechanics of near-extremal black holes\nby Luca Iliesi u (Princeton University) as part of USC High Energy Theory Seminars\n\nLec ture held in (Normally) SSC 319 on University Park Campus (USC).\n\nAbstra ct\nAn important open question in black hole thermodynamics is about the e xistence of a "mass gap" between an extremal black hole and the lightest n ear-extremal state within a sector of fixed charge. In this talk\, I will discuss how to reliably compute the partition function of 4d Reissner-Nord strom near-extremal black holes at temperature scales comparable to the co njectured gap. I will show that the density of states at fixed charge does not exhibit a gap\; rather\, at the expected gap energy scale\, we see a continuum of states whose meaning we will extensively discuss. Finally\, i f time permits\, I will present a similar computation for nearly-BPS black holes in 4d N=2 supergravity. As opposed to their non-supersymmetric coun terparts\, such black holes in fact do exhibit a gap consistent with vario us string theory predictions. \n\n********\n\nWaiting room enabled. Pleas e wait some moments for access. Only participants displaying a real name w ill be admitted.\n\nZoom Meeting ID: 917 8410 6071\nPasscode: 080517\n\nWa iting room enabled. Please wait some moments for access. Only participants displaying a real name will be admitted.\n\nZoom Meeting ID: 917 8410 607 1\nPasscode: 080517\n LOCATION:https://researchseminars.org/talk/USC-HET/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Thomas Mertens (Gent University) DTSTART:20201027T170000Z DTEND:20201027T181500Z DTSTAMP:20260422T225926Z UID:USC-HET/6 DESCRIPTION:Title: Liouville and JT quantum gravity - holography and matrix models\nby Th omas Mertens (Gent University) as part of USC High Energy Theory Seminars\ n\nLecture held in Zoom. (Normally) SSC 319 on University Park Campus (USC ).\n\nAbstract\nIn this talk\, we will discuss recent progress in understa nding quantum gravity amplitudes (partition function and boundary correlat ion functions) in Liouville gravity\, and how they limit to Jackiw-Teitelb oim (JT) correlators. We also discuss multiboundary and higher genus ampli tudes. We focus on two main results: the Liouville gravity answers look li ke q-deformations of the JT answers\, and Liouville gravity can be related to a 2d dilaton gravity with a sinh dilaton potential. We end with discus sions on supersymmetric extensions and work in progress. Based largely on arXiv:2006.07072 and 2007.00998.\n\nZoom Meeting ID: 983 6213 2972\nPasswo rd: 262175 (You will enter a waiting room at first. Admittance granted to people displaying full names.)\n\nZoom Meeting ID: 983 6213 2972\nPassword : 262175\n(You will enter a waiting room at first. Admittance granted to p eople displaying full names.)\n LOCATION:https://researchseminars.org/talk/USC-HET/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Eric d’Hoker (UCLA) DTSTART:20201103T180000Z DTEND:20201103T191500Z DTSTAMP:20260422T225926Z UID:USC-HET/7 DESCRIPTION:Title: Alternative method to extract von Neumann entropy from Renyi entropies \nby Eric d’Hoker (UCLA) as part of USC High Energy Theory Seminars\n\nL ecture held in Zoom. (Normally) SSC 319 on University Park Campus (USC).\n \nAbstract\nAn alternative method is developed for extracting the von Neum ann entropy from the Renyi entropies without having to rely on the replica trick and analytic continuation from integers. Instead a generating funct ion for the Renyi entropies in an auxiliary complex variable z is analytic ally continued in z. Simple analytical and numerical calculations are give n as examples.\n\n-----------------------\n\nZoom details below. Note that you will enter a waiting room for a short while. Participants displaying a name will be admitted.\n\nMeeting ID: 942 0790 7350\n\nPasscode: 778047\ n\nZoom details below. Note that you will enter a waiting room for a short while. Participants displaying a name will be admitted.\n\nMeeting ID: 94 2 0790 7350\n\nPasscode: 778047\n LOCATION:https://researchseminars.org/talk/USC-HET/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Kazumi Okuyama (Shinshu University) DTSTART:20201111T000000Z DTEND:20201111T011500Z DTSTAMP:20260422T225926Z UID:USC-HET/8 DESCRIPTION:Title: Quenched free energy in random matrix model (Note special Time)\nby Ka zumi Okuyama (Shinshu University) as part of USC High Energy Theory Semina rs\n\nLecture held in Zoom. (Normally) SSC 319 on University Park Campus ( USC).\n\nAbstract\nWe compute the quenched free energy in the Gaussian ran dom matrix model by directly evaluating the matrix integral without using the replica trick. We find that the quenched free energy is a monotonic fu nction of the temperature and the entropy approaches log N at high tempera ture and vanishes at zero temperature.\n\nThis talk is based on [arxiv:190 3.11776] and [arxiv:2009.02840].\n\nZoom Meeting ID: 919 4346 8638\nPassco de: 267296\n(You will enter a waiting room at first. Admittance granted to people displaying full names.)\n\nZoom Meeting ID: 919 4346 8638\nPasscod e: 267296\n(You will enter a waiting room at first. Admittance granted to people displaying full names.)\n LOCATION:https://researchseminars.org/talk/USC-HET/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Namit Anand (USC) DTSTART:20201124T180000Z DTEND:20201124T191500Z DTSTAMP:20260422T225926Z UID:USC-HET/10 DESCRIPTION:Title: Quantum coherence as a signature of chaos\nby Namit Anand (USC) as pa rt of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Normally) SSC 319 on University Park Campus (USC).\n\nAbstract\nBased on Ref. [1]: W e establish a rigorous connection between quantum coherence and quantum ch aos by employing coherence measures originating from the resource theory f ramework as a diagnostic tool for quantum chaos. We quantify this connecti on at two different levels: quantum states and quantum channels. At the le vel of states\, we show how several well-studied quantifiers of chaos are\ , in fact\, quantum coherence measures in disguise (or closely related to them). We further this connection for all quantum coherence measures by us ing tools from majorization theory. Then\, we numerically study the cohere nce of chaotic-vs-integrable eigenstates and find excellent agreement with random matrix theory in the bulk of the spectrum. At the level of channel s\, we show that the coherence-generating power (CGP) -- a measure of how much coherence a dynamical process generates on average -- emerges as a su bpart of the out-of-time-ordered correlator (OTOC)\, a measure of informat ion scrambling in many-body systems. Via numerical simulations of the (non integrable) transverse-field Ising model\, we show that the OTOC and CGP c apture quantum recurrences in quantitatively the same way. Moreover\, usin g random matrix theory\, we analytically characterize the CGP-OTOC connect ion for the Haar and Gaussian ensembles. In closing\, we remark on how our coherence-based signatures of chaos relate to other diagnostics\, namely the Loschmidt echo\, OTOC\, and the Spectral Form Factor.\n\nZoom meeting info:\n\nMeeting ID: 945 2045 7223\n\nPasscode: 869242\n\n(You will briefl y enter a waiting room. Participants showing a full name will be admitted. )\n\nZoom meeting info:\nMeeting ID: 945 2045 7223\nPasscode: 869242\n\n(Y ou will briefly enter a waiting room. Participants showing a full name wil l be admitted.)\n LOCATION:https://researchseminars.org/talk/USC-HET/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Kristan Jensen (Univ. of Victoria) DTSTART:20210226T181500Z DTEND:20210226T191500Z DTSTAMP:20260422T225926Z UID:USC-HET/11 DESCRIPTION:Title: Euclidean Wormholes in AdS/CFT\nby Kristan Jensen (Univ. of Victoria) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Norm ally) SSC 319 on University Park Campus (USC).\n\nAbstract\nEuclidean worm holes\, geometries that smoothly connect multiple asymptotic regions\, pos e a conundrum in the AdS/CFT correspondence. I will discuss the constructi on of certain “simple" wormholes in pure Einstein gravity with negative cosmological constant\, and in IIB supergravity. These wormholes connect t wo asymptotic boundaries which have the topology of either a torus or a ci rcle times a sphere. In this setting there are no saddle points which smoo thly connect the two boundaries. Our approach is to then take Einstein gra vity or supergravity seriously as an effective field theory\, in which one sums over metrics\, and to attempt to study the off-shell gravity path in tegral over wormhole metrics. This problem is formally analogous to one in the Higgs phase of 4d gauge theories coupled to matter\, where the Higgs vev forbids instanton solutions\, and yet the theory receives instanton-li ke non-perturbative corrections. In that setting it has been known since t he 80s that there are “constrained instantons” which are in a precise sense the most important off-shell configurations for non-perturbative eff ects. Using similar methods\, we find the “most important” wormhole ge ometries\, which we then use to write a (formal) semiclassical approximati on to the sum over metrics of this sort. I will also discuss the perturbat ive and non-stability of these geometries\, and the tension they pose with the standard AdS/CFT dictionary.\n\nZoom Meeting ID: 913 2401 0873\n\nhtt ps://usc.zoom.us/j/91324010873\n LOCATION:https://researchseminars.org/talk/USC-HET/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Hirosi Ooguri (Caltech & Kavli IPMU) DTSTART:20210430T160000Z DTEND:20210430T181500Z DTSTAMP:20260422T225926Z UID:USC-HET/12 DESCRIPTION:Title: Narain to Narnia\nby Hirosi Ooguri (Caltech & Kavli IPMU) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Normally) SSC 31 9 on University Park Campus (USC).\n\nAbstract\nRecently\, a new type of h olographic pair has been found\, in which quantum gravity theories are dua l to random ensembles of quantum mechanical systems in one and two dimensi ons. This discovery has revived questions on the role of wormholes in quan tum gravity and its implications in holography. I will discuss their gener alization in the context of three-dimensional gravity theories. Mathematic al theory of knots and their relation to hyperbolic geometry plays an impo rtant role.\n\nYou will enter a waiting room for a short while. Please use your real name in your zoom session so that we can distinguish you from r andom passers-by.\n LOCATION:https://researchseminars.org/talk/USC-HET/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Zhu-Xi Luo (UCSB) DTSTART:20210430T180000Z DTEND:20210430T191500Z DTSTAMP:20260422T225926Z UID:USC-HET/13 DESCRIPTION:Title: Holographic duality for Ising CFT with boundary\nby Zhu-Xi Luo (UCSB) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Norm ally) SSC 319 on University Park Campus (USC).\n\nAbstract\nWe extend the holographic duality between 3d pure gravity and the 2d Ising CFT proposed in Ref. [Phys. Rev. D 85 (2012) 024032] to CFTs with boundaries. Besides t he usual asymptotic boundary\, the dual bulk spacetime now has a real cuto ff\, on which live branes with finite tension\, giving Neumann boundary co ndition on the metric tensor. The strongly-coupled bulk theory requires th at we dress the well-known semiclassical AdS/BCFT answer with boundary gra vitons\, turning the partition function into the form of Virasoro characte rs. Using this duality\, we relate the brane tensions to the modular S-mat rix elements of the dual BCFT and derive the transformation between gravit ational solutions with different brane tensions under modular S action.\n\ nYou will enter a waiting room for a short while. Please use your real nam e in your zoom session so that we can distinguish you from random passers- by.\n LOCATION:https://researchseminars.org/talk/USC-HET/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Ruben Monten (UCLA) DTSTART:20210430T200000Z DTEND:20210430T211500Z DTSTAMP:20260422T225926Z UID:USC-HET/14 DESCRIPTION:Title: 3D Gravity in a Box\nby Ruben Monten (UCLA) as part of USC High Energ y Theory Seminars\n\nLecture held in Zoom. (Normally) SSC 319 on Universit y Park Campus (USC).\n\nAbstract\nKnown gravitational theories only have a symptotic boundary observables. To calculate more local quantities — and also to implement the conjectured holographic interpretation of the TTbar deformation — one can consider pure three-dimensional gravity on spacet imes with a boundary of finite size. I will describe how the covariant pha se space framework can be used to calculate the Poisson bracket algebra of boundary observables. It is then possible to quantize this system\, takin g inspiration from the coadjoint orbit formalism. Working perturbatively i n the large c expansion\, we obtain the deformed Alekseev–Shatashvili sy mplectic form and action\, as well as the energy spectrum which is consist ent with the TTbar prediction up to order 1/√c.\n\nYou will enter a wait ing room for a short while. Please use your real name in your zoom session so that we can distinguish you from random passers-by.\n LOCATION:https://researchseminars.org/talk/USC-HET/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Dionysios Anninos (King's College London) DTSTART:20210507T170000Z DTEND:20210507T181500Z DTSTAMP:20260422T225926Z UID:USC-HET/15 DESCRIPTION:Title: Comments on Matrices & Spheres\nby Dionysios Anninos (King's College London) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom . (Normally) SSC 319 on University Park Campus (USC).\n\nAbstract\nWe stud y the partition function of quantum fields on the Euclidean sphere and its relation to the thermodynamics of the de Sitter horizon and the Gibbons-H awking entropy. For the case of the two-sphere\, we explore the relation b etween two-dimensional quantum gravity coupled to conformal matter and mat rix integrals. We discuss how such two-dimensional models may shed light o n Euclidean gravity with a positive cosmological constant.\n\n(Sorry\, no external access to this talk is available. A recording may be posted later . Thanks for understanding.)\n LOCATION:https://researchseminars.org/talk/USC-HET/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrew Svesko (UCL (UK)) DTSTART:20230201T201500Z DTEND:20230201T213000Z DTSTAMP:20260422T225926Z UID:USC-HET/16 DESCRIPTION:Title: Higher-dimensional origin of extended black hole thermodynamics\nby A ndrew Svesko (UCL (UK)) as part of USC High Energy Theory Seminars\n\nLect ure held in Zoom. (Normally) SSC 319 on University Park Campus (USC).\n\nA bstract\nA key difference between black holes and ordinary thermal systems is the absence of a pressure-volume work term in the first law of black h ole thermodynamics. It is possible to introduce such a work term for black holes in backgrounds with a cosmological constant by treating the cosmolo gical constant as a pressure\,offering a rich gravitational perspective on everyday phenomena. Missing\, however\, is justification for allowing va riations of the cosmological constant. In this talk I will present a highe r-dimensional origin of 'extended black hole thermodynamics' using hologra phic braneworlds. In this set-up\, gravity is coupled to a lower-dimension al membrane such that classical black holes in a bulk anti-de Sitter space time correspond to exact quantum corrected black holes localized on the br ane\, including all orders of semi-classical backreaction. Crucially\, va rying the tension of the brane leads to a dynamical cosmological constant on the brane\, and\, correspondingly\, a variable pressure attributed to t he brane black hole. In other words\, standard thermodynamics of classical black holes induces extended thermodynamics of quantum black holes on a b rane. As proof of concept\, I will present the extended thermodynamics of the quantum BTZ black hole\, also providing a microscopic interpretation u sing `double holography’.\n LOCATION:https://researchseminars.org/talk/USC-HET/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Alicia Castro (IMAPP\, Radboud University) DTSTART:20230426T191500Z DTEND:20230426T204500Z DTSTAMP:20260422T225926Z UID:USC-HET/17 DESCRIPTION:Title: Critical JT Gravity\nby Alicia Castro (IMAPP\, Radboud University) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom\, and SSC 319 on University Park Campus (USC).\n\nAbstract\nIn this talk\, I will p resent JT-like gravity\, a model of two-dimensional quantum gravity on con stant negatively curved spacetimes\, as a model of random hyperbolic surf aces. By studying the generating function of volumes of random hyperbolic surfaces with defects\, i.e. weighted geodesic boundaries\, we explore cri tical regimes where the surfaces develop macroscopic holes. We analyse the impact of this critical behavior on the density of states of the theory a t the boundary\, and we present a family of models that interpolate betwee n systems with $\\sqrt{E}$ and $E^{3/2}$\, which are commonly found in mod els of JT Gravity coupled to dynamical end-of-the-world and FZZT branes.\n \n(Waiting room will be used for all external participants. Best to show a real name in your Zoom ID to make the process easier.)\n LOCATION:https://researchseminars.org/talk/USC-HET/17/ END:VEVENT END:VCALENDAR