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:20260404T111412Z UID:USC-HET/1 DESCRIPTION:Title: An Introduction to 2-Group Global Symmetry\nby Thomas Dumistres cu (UCLA) as part of USC High Energy Theory Seminars\n\nLecture held in On line only\, but normally: SSC 319 on University Park Campus (USC).\n\nAbst ract\nI will briefly review the generalization of ordinary global symmetri es to higher-form symmetries (which act on extended objects) in quantum fi eld theory. I will then showcase simple but surprising examples in 4d and 6d where ordinary and 1-form global symmetries are necessarily fused toget her into a higher structure known as a 2-group. Time permitting\, I will d iscuss some applications to superconformal theories in 6d.\n\nZoom Meeting ID: 924 6768 3111\nPassword: 620110\n(You will enter a waiting room for a brief period.)\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Ibou Bah (Johns Hopkins U.) DTSTART:20200520T191500Z DTEND:20200520T204500Z DTSTAMP:20260404T111412Z UID:USC-HET/2 DESCRIPTION:Title: Anomaly Inflow and Geometric Engineering of Quantum Field Theory\nby Ibou Bah (Johns Hopkins U.) as part of USC High Energy Theory Semina rs\n\nLecture held in SSC 319 on University Park Campus (USC).\n\nAbstract \nTitle: Anomaly Inflow and Geometric Engineering of Quantum Field Theory\ n\nAbstract: In this talk\, I will review recent results in using string t heory to compute anomalies of quantum fields theories. In particular\, I will describe reductions of anomaly polynomials in type IIB string theory and M-theory on compact spaces to capture the anomalies for quantum field theories that describe the low-energy dynamics of branes in various config urations. As examples of these methods\, I will describe how to obtain th e anomalies of quantum field theories in the reduction of SCFTs in 6d and 4d on punctured Riemann surfaces. Another interesting example that will b e discussed is the theory of M5-branes probing a Z_2 orbifold fixed point while wrapping Riemann surfaces. The anomaly inflow analysis in this latte r example lead to the identification of its holographic duals.\n\nZoom Mee ting ID: 927 1418 2739\nPassword: 861608\nYou will enter a waiting room fo r a short while.\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Christoph Uhlemann (U. Michigan) DTSTART:20200422T191500Z DTEND:20200422T204500Z DTSTAMP:20260404T111412Z UID:USC-HET/3 DESCRIPTION:Title: Wilson loops in 5d long quiver gauge theories\nby Christoph Uhl emann (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 theories with a large number of nodes host a rich spectrum of line operat ors\, including Wilson loops associated with each individual gauge node. E xact results are discussed for Wilson loops in fundamental and k-fold anti symmetric representations\, for a sample of 5d long quiver gauge theories whose UV fixed points have holographic duals in Type IIB. The holographic representation of the Wilson loops is identified\, and yields interesting insights into the holographic duals.\n\nhttps://usc.zoom.us/j/98353393583\ n\nMeeting ID: 983 5339 3583\nPassword: 186449\n\nYou will enter a waiting room for a short while.\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Felipe Rosso (USC) DTSTART:20200527T191500Z DTEND:20200527T204500Z DTSTAMP:20260404T111412Z 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\nAbstract\nThe achronal Averaged Null Energy Condition (ANEC) is a co njectured bound on the stress tensor in semi-classical gravity that has de ep implications for both gravitational and quantum theories. While several arguments have been given in favor of this condition\, concrete and gener al proofs are so far only available in Minkowski. In this talk I explain h ow the achronal ANEC can be explicitly derived using quantum information t heory for general QFTs in the near horizon of extremal black holes\, de Si tter and anti-de Sitter.\n\nZoom meeting ID: 925 2872 4339\nPassword: 5792 12\n\n(You will enter a waiting room for a short while.)\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Luca Iliesiu (Princeton University) DTSTART:20201020T170000Z DTEND:20201020T181500Z DTSTAMP:20260404T111412Z UID:USC-HET/5 DESCRIPTION:Title: The statistical mechanics of near-extremal black holes\nby Luca Iliesiu (Princeton University) as part of USC High Energy Theory Seminars \n\nLecture held in (Normally) SSC 319 on University Park Campus (USC).\n\ nAbstract\nAn important open question in black hole thermodynamics is abou t the existence of a "mass gap" between an extremal black hole and the lig htest near-extremal state within a sector of fixed charge. In this talk\, I will discuss how to reliably compute the partition function of 4d Reissn er-Nordstrom near-extremal black holes at temperature scales comparable to the conjectured gap. I will show that the density of states at fixed char ge does not exhibit a gap\; rather\, at the expected gap energy scale\, we see a continuum of states whose meaning we will extensively discuss. Fina lly\, if time permits\, I will present a similar computation for nearly-BP S black holes in 4d N=2 supergravity. As opposed to their non-supersymmetr ic counterparts\, such black holes in fact do exhibit a gap consistent wit h various string theory predictions. \n\n********\n\nWaiting room enabled . Please wait some moments for access. Only participants displaying a real name will be admitted.\n\nZoom Meeting ID: 917 8410 6071\nPasscode: 08051 7\n\nWaiting room enabled. Please wait some moments for access. Only parti cipants displaying a real name will be admitted.\n\nZoom Meeting ID: 917 8 410 6071\nPasscode: 080517\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Thomas Mertens (Gent University) DTSTART:20201027T170000Z DTEND:20201027T181500Z DTSTAMP:20260404T111412Z UID:USC-HET/6 DESCRIPTION:Title: Liouville and JT quantum gravity - holography and matrix models \nby Thomas Mertens (Gent University) as part of USC High Energy Theory Se minars\n\nLecture held in Zoom. (Normally) SSC 319 on University Park Camp us (USC).\n\nAbstract\nIn this talk\, we will discuss recent progress in u nderstanding quantum gravity amplitudes (partition function and boundary c orrelation functions) in Liouville gravity\, and how they limit to Jackiw- Teitelboim (JT) correlators. We also discuss multiboundary and higher genu s amplitudes. We focus on two main results: the Liouville gravity answers look like 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 discussions on supersymmetric extensions and work in progress. Based larg ely on arXiv:2006.07072 and 2007.00998.\n\nZoom Meeting ID: 983 6213 2972\ nPassword: 262175 (You will enter a waiting room at first. Admittance gran ted to people displaying full names.)\n\nZoom Meeting ID: 983 6213 2972\nP assword: 262175\n(You will enter a waiting room at first. Admittance grant ed to people displaying full names.)\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Eric d’Hoker (UCLA) DTSTART:20201103T180000Z DTEND:20201103T191500Z DTSTAMP:20260404T111412Z UID:USC-HET/7 DESCRIPTION:Title: Alternative method to extract von Neumann entropy from Renyi entrop ies\nby Eric d’Hoker (UCLA) as part of USC High Energy Theory Semina rs\n\nLecture held in Zoom. (Normally) SSC 319 on University Park Campus ( USC).\n\nAbstract\nAn alternative method is developed for extracting the v on Neumann entropy from the Renyi entropies without having to rely on the replica trick and analytic continuation from integers. Instead a generatin g function for the Renyi entropies in an auxiliary complex variable z is a nalytically continued in z. Simple analytical and numerical calculations a re given as examples.\n\n-----------------------\n\nZoom details below. No te that you will enter a waiting room for a short while. Participants disp laying 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: 942 0790 7350\n\nPasscode: 778047\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Kazumi Okuyama (Shinshu University) DTSTART:20201111T000000Z DTEND:20201111T011500Z DTSTAMP:20260404T111412Z UID:USC-HET/8 DESCRIPTION:Title: Quenched free energy in random matrix model (Note special Time) \nby Kazumi Okuyama (Shinshu University) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Normally) SSC 319 on University Park C ampus (USC).\n\nAbstract\nWe compute the quenched free energy in the Gauss ian random matrix model by directly evaluating the matrix integral without using the replica trick. We find that the quenched free energy is a monot onic function of the temperature and the entropy approaches log N at high temperature and vanishes at zero temperature.\n\nThis talk is based on [ar xiv:1903.11776] and [arxiv:2009.02840].\n\nZoom Meeting ID: 919 4346 8638\ nPasscode: 267296\n(You will enter a waiting room at first. Admittance gra nted to people displaying full names.)\n\nZoom Meeting ID: 919 4346 8638\n Passcode: 267296\n(You will enter a waiting room at first. Admittance gran ted to people displaying full names.)\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Namit Anand (USC) DTSTART:20201124T180000Z DTEND:20201124T191500Z DTSTAMP:20260404T111412Z UID:USC-HET/10 DESCRIPTION:Title: Quantum coherence as a signature of chaos\nby Namit Anand (USC ) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Nor mally) SSC 319 on University Park Campus (USC).\n\nAbstract\nBased on Ref. [1]: We establish a rigorous connection between quantum coherence and qua ntum chaos by employing coherence measures originating from the resource t heory framework as a diagnostic tool for quantum chaos. We quantify this c onnection at two different levels: quantum states and quantum channels. At the level of states\, we show how several well-studied quantifiers of cha os are\, in fact\, quantum coherence measures in disguise (or closely rela ted to them). We further this connection for all quantum coherence measure s by using tools from majorization theory. Then\, we numerically study the coherence of chaotic-vs-integrable eigenstates and find excellent agreeme nt with random matrix theory in the bulk of the spectrum. At the level of channels\, we show that the coherence-generating power (CGP) -- a measure of how much coherence a dynamical process generates on average -- emerges as a subpart of the out-of-time-ordered correlator (OTOC)\, a measure of i nformation scrambling in many-body systems. Via numerical simulations of t he (nonintegrable) transverse-field Ising model\, we show that the OTOC an d CGP capture quantum recurrences in quantitatively the same way. Moreover \, using random matrix theory\, we analytically characterize the CGP-OTOC connection 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 m eeting info:\n\nMeeting ID: 945 2045 7223\n\nPasscode: 869242\n\n(You will briefly enter a waiting room. Participants showing a full name will be ad mitted.)\n\nZoom meeting info:\nMeeting ID: 945 2045 7223\nPasscode: 86924 2\n\n(You will briefly enter a waiting room. Participants showing a full n ame will be admitted.)\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Kristan Jensen (Univ. of Victoria) DTSTART:20210226T181500Z DTEND:20210226T191500Z DTSTAMP:20260404T111412Z UID:USC-HET/11 DESCRIPTION:Title: Euclidean Wormholes in AdS/CFT\nby Kristan Jensen (Univ. of Vi ctoria) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom . (Normally) SSC 319 on University Park Campus (USC).\n\nAbstract\nEuclide an wormholes\, geometries that smoothly connect multiple asymptotic region s\, pose a conundrum in the AdS/CFT correspondence. I will discuss the con struction of certain “simple" wormholes in pure Einstein gravity with ne gative cosmological constant\, and in IIB supergravity. These wormholes co nnect two asymptotic boundaries which have the topology of either a torus or a circle times a sphere. In this setting there are no saddle points whi ch smoothly connect the two boundaries. Our approach is to then take Einst ein gravity or supergravity seriously as an effective field theory\, in wh ich one sums over metrics\, and to attempt to study the off-shell gravity path integral 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 insta nton-like non-perturbative corrections. In that setting it has been known since the 80s that there are “constrained instantons” which are in a p recise sense the most important off-shell configurations for non-perturbat ive effects. Using similar methods\, we find the “most important” worm hole geometries\, which we then use to write a (formal) semiclassical appr oximation to the sum over metrics of this sort. I will also discuss the pe rturbative and non-stability of these geometries\, and the tension they po se with the standard AdS/CFT dictionary.\n\nZoom Meeting ID: 913 2401 0873 \n\nhttps://usc.zoom.us/j/91324010873\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Hirosi Ooguri (Caltech & Kavli IPMU) DTSTART:20210430T160000Z DTEND:20210430T181500Z DTSTAMP:20260404T111412Z UID:USC-HET/12 DESCRIPTION:Title: Narain to Narnia\nby Hirosi Ooguri (Caltech & Kavli IPMU) as p art of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Normally) SSC 319 on University Park Campus (USC).\n\nAbstract\nRecently\, a new ty pe of holographic pair has been found\, in which quantum gravity theories are dual to random ensembles of quantum mechanical systems in one and two dimensions. This discovery has revived questions on the role of wormholes in quantum gravity and its implications in holography. I will discuss thei r generalization in the context of three-dimensional gravity theories. Mat hematical theory of knots and their relation to hyperbolic geometry plays an important role.\n\nYou will enter a waiting room for a short while. Ple ase use your real name in your zoom session so that we can distinguish you from random passers-by.\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Zhu-Xi Luo (UCSB) DTSTART:20210430T180000Z DTEND:20210430T191500Z DTSTAMP:20260404T111412Z 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 . (Normally) SSC 319 on University Park Campus (USC).\n\nAbstract\nWe exte nd the holographic duality between 3d pure gravity and the 2d Ising CFT pr oposed in Ref. [Phys. Rev. D 85 (2012) 024032] to CFTs with boundaries. Be sides the usual asymptotic boundary\, the dual bulk spacetime now has a re al cutoff\, on which live branes with finite tension\, giving Neumann boun dary condition on the metric tensor. The strongly-coupled bulk theory requ ires that we dress the well-known semiclassical AdS/BCFT answer with bound ary gravitons\, turning the partition function into the form of Virasoro c haracters. Using this duality\, we relate the brane tensions to the modula r S-matrix elements of the dual BCFT and derive the transformation between gravitational solutions with different brane tensions under modular S act ion.\n\nYou will enter a waiting room for a short while. Please use your r eal name in your zoom session so that we can distinguish you from random p assers-by.\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Ruben Monten (UCLA) DTSTART:20210430T200000Z DTEND:20210430T211500Z DTSTAMP:20260404T111412Z UID:USC-HET/14 DESCRIPTION:Title: 3D Gravity in a Box\nby Ruben Monten (UCLA) as part of USC Hig h Energy Theory Seminars\n\nLecture held in Zoom. (Normally) SSC 319 on Un iversity Park Campus (USC).\n\nAbstract\nKnown gravitational theories only have asymptotic boundary observables. To calculate more local quantities — and also to implement the conjectured holographic interpretation of th e TTbar deformation — one can consider pure three-dimensional gravity on spacetimes with a boundary of finite size. I will describe how the covari ant phase space framework can be used to calculate the Poisson bracket alg ebra of boundary observables. It is then possible to quantize this system\ , taking inspiration from the coadjoint orbit formalism. Working perturbat ively in the large c expansion\, we obtain the deformed Alekseev–Shatash vili symplectic form and action\, as well as the energy spectrum which is consistent with the TTbar prediction up to order 1/√c.\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 random passers-by.\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Dionysios Anninos (King's College London) DTSTART:20210507T170000Z DTEND:20210507T181500Z DTSTAMP:20260404T111412Z UID:USC-HET/15 DESCRIPTION:Title: Comments on Matrices & Spheres\nby Dionysios Anninos (King's C ollege London) as part of USC High Energy Theory Seminars\n\nLecture held in Zoom. (Normally) SSC 319 on University Park Campus (USC).\n\nAbstract\n We study the partition function of quantum fields on the Euclidean sphere and its relation to the thermodynamics of the de Sitter horizon and the Gi bbons-Hawking entropy. For the case of the two-sphere\, we explore the rel ation between two-dimensional quantum gravity coupled to conformal matter and matrix integrals. We discuss how such two-dimensional models may shed light on Euclidean gravity with a positive cosmological constant.\n\n(Sorr y\, no external access to this talk is available. A recording may be poste d later. Thanks for understanding.)\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrew Svesko (UCL (UK)) DTSTART:20230201T201500Z DTEND:20230201T213000Z DTSTAMP:20260404T111412Z UID:USC-HET/16 DESCRIPTION:Title: Higher-dimensional origin of extended black hole thermodynamics\nby Andrew Svesko (UCL (UK)) as part of USC High Energy Theory Seminars\ n\nLecture held in Zoom. (Normally) SSC 319 on University Park Campus (USC ).\n\nAbstract\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 hole thermodynamics. It is possible to introduce such a work term fo r black holes in backgrounds with a cosmological constant by treating the cosmological constant as a pressure\,offering a rich gravitational perspec tive on everyday phenomena. Missing\, however\, is justification for allo wing variations of the cosmological constant. In this talk I will present a higher-dimensional origin of 'extended black hole thermodynamics' using holographic braneworlds. In this set-up\, gravity is coupled to a lower-di mensional membrane such that classical black holes in a bulk anti-de Sitte r spacetime correspond to exact quantum corrected black holes localized on the brane\, including all orders of semi-classical backreaction. Crucial ly\, varying the tension of the brane leads to a dynamical cosmological co nstant on the brane\, and\, correspondingly\, a variable pressure attribut ed to the brane black hole. In other words\, standard thermodynamics of cl assical black holes induces extended thermodynamics of quantum black holes on a brane. As proof of concept\, I will present the extended thermodynam ics of the quantum BTZ black hole\, also providing a microscopic interpret ation using `double holography’.\n LOCATION:https://stable.researchseminars.org/talk/USC-HET/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Alicia Castro (IMAPP\, Radboud University) DTSTART:20230426T191500Z DTEND:20230426T204500Z DTSTAMP:20260404T111412Z UID:USC-HET/17 DESCRIPTION:Title: Critical JT Gravity\nby Alicia Castro (IMAPP\, Radboud Univers ity) 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 present JT-like gravity\, a model of two-dimensional quantum gravity on constant negatively curved spacetimes\, as a model of random hyperbol ic surfaces. By studying the generating function of volumes of random hype rbolic surfaces with defects\, i.e. weighted geodesic boundaries\, we expl ore critical regimes where the surfaces develop macroscopic holes. We anal yse the impact of this critical behavior on the density of states of the t heory at the boundary\, and we present a family of models that interpolate between systems with $\\sqrt{E}$ and $E^{3/2}$\, which are commonly found in models of JT Gravity coupled to dynamical end-of-the-world and FZZT br anes.\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://stable.researchseminars.org/talk/USC-HET/17/ END:VEVENT END:VCALENDAR