BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Luca Delacretaz (University of Chicago) DTSTART:20200430T150000Z DTEND:20200430T160000Z DTSTAMP:20260422T225929Z UID:HoloTube/1 DESCRIPTION:Title: Hydrodynamic Fluctuations\nby Luca Delacretaz (University of Chicago) as part of HoloTube: Applied holography webinars\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/HoloTube/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Eric Mefford (École Polytechnique Paris) DTSTART:20200505T150000Z DTEND:20200505T160000Z DTSTAMP:20260422T225929Z UID:HoloTube/3 DESCRIPTION:Title: Transport in clean quantum critical superfluids\nby Eric Mefford (Éc ole Polytechnique Paris) as part of HoloTube: Applied holography webinars\ n\n\nAbstract\nThe hydrodynamic regime of superfluids in systems like 4He has been well understood since the seminal work of Landau and Tisza. A fun damental assumption in much subsequent work is the low-temperature dominan ce of the superfluid phonon which leads to universal behavior in transport that is characterized by the phonon sound speed. I will discuss investiga tions of the two-fluid model of superfluids near an underlying quantum cri tical phase and establish criteria for the breakdown of this assumption wh ich leads to novel transport behavior. A surprising result is the non-vani shing of the charge density of the fluid’s normal component at zero temp erature. I will illustrate these results with some holographic models.\n LOCATION:https://researchseminars.org/talk/HoloTube/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Chandan Setty (University of Florida) DTSTART:20200512T140000Z DTEND:20200512T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/4 DESCRIPTION:Title: Pairing instability on Luttinger Surfaces : SYK thermodynamics from a con densed matter perspective\nby Chandan Setty (University of Florida) as part of HoloTube: Applied holography webinars\n\n\nAbstract\nSuperconduct ivity results from an instability of the Fermi surface — contour of pole s of the single particle propagator — to an infinitesimally small attrac tive inter-particle attraction. In this talk\, I will instead discuss the analogous problem on a model Luttinger Surface — contour of zeros of the Green function. Unlike a Fermi surface\, in the presence of an attracti ve potential\, the model exhibits a quantum phase transition from a non-Fe rmi liquid to a superconducting state. Crucially\, pair-fluctuations clos e to the transition resemble well-studied models with gravity duals such a s SYK. I will discuss implications of this result to microscopic models de scribing Mott physics.\n LOCATION:https://researchseminars.org/talk/HoloTube/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Richard Davison (Heriot-Watt University) DTSTART:20200519T140000Z DTEND:20200519T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/5 DESCRIPTION:Title: Relations between transport and chaos in holographic theories\nby Ric hard Davison (Heriot-Watt University) as part of HoloTube: Applied hologra phy webinars\n\n\nAbstract\nI will describe recent work illustrating gener al relations between the transport properties and chaotic properties of qu antum field theories with holographic duals. I will firstly show how a sim ple analysis of near-horizon dynamics yields exact constraints on the spec trum of collective excitations. I will then describe how this can be explo ited to identify a universal feature in the spectrum\, and its implication s for the collective transport properties of strongly interacting field th eories with gravity duals.\n LOCATION:https://researchseminars.org/talk/HoloTube/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Rene Meyer (University of Wurzburg) DTSTART:20200602T140000Z DTEND:20200602T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/7 DESCRIPTION:Title: Strongly correlated Dirac materials\, electron hydrodynamics & AdS/CFT\nby Rene Meyer (University of Wurzburg) as part of HoloTube: Applied hol ography webinars\n\n\nAbstract\nA current challenge in condensed matter ph ysics is the realization of strongly correlated\, viscous electron fluids. These fluids are not amenable to the perturbative methods of Fermi liquid theory\, but can be described by holography\, that is\, by mapping them o nto a weakly curved gravitational theory via gauge/gravity duality. The ca nonical system considered for realizations has been graphene\, which posse sses Dirac dispersions at low energies as well as significant Coulomb inte ractions between the electrons. In this talk\, after introducing basic not ions of hydrodynamics and holography\, I will discuss Kagome systems which \, with electron fillings adjusted to the Dirac nodes of their band struct ure\, provide a much more compelling platform for realizations of viscous electron fluids\, including non-linear effects such as turbulence. In par ticular\, in stoichiometric Scandium (Sc) Herbertsmithite\, the fine-struc ture constant\, which measures the effective Coulomb interaction and hence reflects the strength of the correlations\, is enhanced by a factor of ab out 3.2 as compared to graphene. I will present a holographic model which includes the leading finite coupling corrections and allows to estimate th e ratio of shear viscosity over entropy density in Sc-Herbertsmithite\, an d find it about three times smaller than in graphene. These findings put\, for the first time\, the turbulent flow regime described by holography wi thin the reach of experiments.\n LOCATION:https://researchseminars.org/talk/HoloTube/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Matteo Baggioli (host) (IFT Madrid) DTSTART:20200526T140000Z DTEND:20200526T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/8 DESCRIPTION:Title: Discussion about the applications of Holography\nby Matteo Baggioli ( host) (IFT Madrid) as part of HoloTube: Applied holography webinars\n\n\nA bstract\nPanelists: Luca Delacretaz (Chicago)\, Blaise Gouteraux (Paris)\, Saso Grozdanov (MIT & Ljubljana)\, Carlos Hoyos (Oviedo)\, Koenraad Schal m (Leiden)\, Jan Zaanen (Leiden).\n\nAfter more than a Decade of effort in to holography and its applications\, it is a perfect moment to put\noursel ves on trial. What did we learn? What are we doing? And\, most importantly \, what are we going to do next? With the help of the top experts in the c ommunity\, we will try to address all of the above questions in an interac tive panel discussion. As a moderator\, I will propose specific and concre te questions about the last developments in the subject. All participants are highly encouraged to bring\ntheir own questions and interact during th e panel discussion.\n LOCATION:https://researchseminars.org/talk/HoloTube/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Ayan Mukhopadhyay (Indian Institute Of Technology Madras) DTSTART:20200609T140000Z DTEND:20200609T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/9 DESCRIPTION:Title: SL(2\,R) lattices and networks as information mirrors and decoders\nb y Ayan Mukhopadhyay (Indian Institute Of Technology Madras) as part of Hol oTube: Applied holography webinars\n\n\nAbstract\nQuantum black holes past their Page times are unique objects in terms of how they process quantum information. Thinking of such black holes as quantum circuits\, it has bee n argued that while infalling information after Page time comes out quickl y at the order of Hayden-Preskill time\, processing the information about the black hole interior will require timescales that are much larger than the evaporation time of the black hole in order to avoid information parad oxes. Thus quantum black holes acts as information mirrors that reveals th e bits that fell in just after Page time first and its own formation later . Motivated by the fragmented horizon picture\, we construct a simple mode l that can capture the essence of quantum black holes in terms of its info rmation processing. Our model is a lattice of nearly two-dimensional anti- de Sitter spaces interacting with mobile quantum hair carrying gravitation al charges. We will show that this model can realize the Hayden-Preskill p rotocol while not encountering information paradoxes due to inherent pseud orandomness and scrambling. Furthermore\, we will discuss well motivated g eneralizations of this model that are analogous to tensor networks. We wil l argue these can provide computable “fragmented holographic” framewo rks for general semi-local non-Fermi liquids and other strongly correlated systems.\n LOCATION:https://researchseminars.org/talk/HoloTube/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Umut Gürsoy (University of Utrecht) DTSTART:20200616T140000Z DTEND:20200616T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/10 DESCRIPTION:Title: Holography of the spin current\nby Umut Gürsoy (University of Utrec ht) as part of HoloTube: Applied holography webinars\n\n\nAbstract\nRecent developments both in high and low energy physics have increased the impor tance of hydrodynamics of matter with correlated spin degrees of freedom. In particular\, Takahashi et al managed to create stable spin currents in liquid metals sourced by vorticity\, and the STAR collaboration at RHIC ob served nontrivial polarization of hyperon particles in off-central heavy i on collisions. Theoretical understanding of these findings requires adding the spin current to (relativistic) hydrodynamics as a new degree of freed om. In this talk — that will be based on arXiv:2004.05148 — I will de scribe how this can be done by sourcing the spin current by torsion. I wil l classify different types of torsion in 3+1 dimensions and develop the co rresponding constitutive equations for the energy-momentum tensor and the spin current. We will then analyze the problem in a toy holographic model based on the 5D Lovelock-Chern-Simons theory. As a byproduct\, I will intr oduce a number of previously unknown blackhole solutions to this theory a nd map these solutions to hydrodynamics by the fluid-gravity correspondenc e. The resulting energy-momentum and spin flow exhibits interesting featur es including a dynamical version of the Barnett effect and indicate variou s novel mechanisms through which spin currents may be generated in strongl y correlated systems.\n LOCATION:https://researchseminars.org/talk/HoloTube/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Sera Cremonini (University of Lehigh) DTSTART:20200623T140000Z DTEND:20200623T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/11 DESCRIPTION:Title: Constraining Non-Relativistic RG Flows with Holography\nby Sera Crem onini (University of Lehigh) as part of HoloTube: Applied holography webin ars\n\n\nAbstract\nThe basic question of how to organize the degrees of fr eedom of a quantum system as a function of energy scale has proven very di fficult to address in a general context. The powerful c-theorems\, for exa mple\, which provide a clear measure for the number of effective degrees o f freedom through the existence of a monotonic c-function\, rely crucially on Lorentz invariance. In this talk I will discuss attempts to identify p otential generalizations of a c-function within the context of non-relativ istic holographic RG flows. In particular\, I will examine Einstein-Maxwel l-scalar theories that support geometries that are not Lorentz invariant a t all energy scales\, and identify several quantities that behave monotoni cally along RG flow. While some results are completely generic in Einstein -Maxwell-scalar theories\, others will only hold in Einstein-scalar theori es.\n LOCATION:https://researchseminars.org/talk/HoloTube/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Moshe Rozali (UBC Vancouver) DTSTART:20200630T140000Z DTEND:20200630T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/12 DESCRIPTION:Title: Effective Field Theory for Chaotic CFTs\nby Moshe Rozali (UBC Vancou ver) as part of HoloTube: Applied holography webinars\n\n\nAbstract\nRelat ions between chaos and hydrodynamics are one of the unique feature of holo graphic CFTs. The early time Lyapunov regime can described by an effective field theory of a single mode\, which for maximally chaotic systems is an hydrodynamic mode. We describe that effective field theory for conformal field theories\, both in two dimensions and in higher dimensions\, and sho w how it captures maximal chaos and pole skipping. We discuss the relation of the theory to other formulations of CFTs and show how it captures inte resting objects such as conformal blocks and partial waves. We speculate o n what is needed to extend the discussion to non maximal chaos.\n LOCATION:https://researchseminars.org/talk/HoloTube/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Rajeev Singh (Institute of Nuclear Physics Polish Academy of Scien ces) DTSTART:20200707T140000Z DTEND:20200707T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/13 DESCRIPTION:Title: A new hydrodynamics with spin formalism for the description of polarizat ion effect of Lambda hyperons\nby Rajeev Singh (Institute of Nuclear P hysics Polish Academy of Sciences) as part of HoloTube: Applied holography webinars\n\n\nAbstract\nMeasurements made recently by the STAR collaborat ion show that the Lambda hyperons produced in relativistic heavy-ion colli sions are subject to global spin polarization with respect to an axis coin cident with the axis of rotation of the produced matter. Recently formulat ed formalism of relativistic hydrodynamics with spin\, which is a generali zation of the standard hydrodynamics\, is a natural tool for describing th e evolution of such systems. This approach is based on the conservation la ws and the form of the energy-momentum tensor and spin tensor postulated b y de Groot\, van Leeuwen\, and van Weert (GLW). Using Bjorken symmetry we show how this formalism may be used to determine observables describing th e polarization of particles measured in the experiment.\n LOCATION:https://researchseminars.org/talk/HoloTube/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexander Krikun (Nordita) DTSTART:20200714T140000Z DTEND:20200714T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/14 DESCRIPTION:Title: Coherent and incoherent transport in holographic models with spontaneous ly broken translations\nby Alexander Krikun (Nordita) as part of HoloT ube: Applied holography webinars\n\n\nAbstract\nIn holography it is relati vely easy to construct the models which break translation symmetry either explicitly\, or spontaneously\, or both. AC transport in these models has a few interesting features\, which were in focus for the past few years\, including the gapped “pseudo-Goldstone” mode\, the metal — Mott insu lator transition\, the residual incoherent conductivity and the contributi on of the gapped coherent peak in DC conductivity due to “phase relaxati on”. It is particularly interesting to study these features in detail\, since they might have a direct representation in the experimental data on cuprates and doped Mott insulators. I will overview the subject and presen t several recent observations in models with either helical or periodic ho lographic lattices\, which shed some light on the physics behind these int eresting features.\n LOCATION:https://researchseminars.org/talk/HoloTube/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Kévin Nguyen (Harvard University) DTSTART:20200721T140000Z DTEND:20200721T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/15 DESCRIPTION:Title: Superluminal chaos after a quantum quench\nby Kévin Nguyen (Harvard University) as part of HoloTube: Applied holography webinars\n\n\nAbstrac t\nI will present a formula to compute out-of-time-order correlators (OTOC ) in generic asymptotically AdS spacetimes\, based on the geodesic approxi mation to bulk propagators and the exchange of gravitational shock waves. In contrast to the standard method of Shenker and Stanford\, this formula does not require to work in Fourier space and is therefore better suited w hen considering time-dependent holographic states. Applying this new metho d to the computation of OTOCs in quenched states dual to collapsing thin s hells of matter (Vaidya spacetimes)\, we discover a transient superluminal ity in the butterfly velocity characterizing information scrambling in the system.\n LOCATION:https://researchseminars.org/talk/HoloTube/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Mario Flory (Jagiellonian University) DTSTART:20200728T140000Z DTEND:20200728T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/16 DESCRIPTION:Title: Complexity and Conformal Field Theory\nby Mario Flory (Jagiellonian University) as part of HoloTube: Applied holography webinars\n\n\nAbstract \nWe study circuit and state complexity in the universal setting of (1+1)- dimensional conformal ​ field theory and unitary transformations generat ed by the stress-energy tensor. We provide a unifi​ed view of assigning a cost to circuits based on the Fubini-Study metric\, iteratively solve th e emerging integro-diff​erential equation for sample optimal circuits an d discuss the sectional curvature of the underlying geometry. We also disc uss the relation of our work to Euler-Arnold type equations such as the Ko rteweg-de Vries and Hunter-Saxton equations.\n LOCATION:https://researchseminars.org/talk/HoloTube/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Jelle Hartong (University of Edinburgh) DTSTART:20200901T140000Z DTEND:20200901T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/17 DESCRIPTION:Title: Dynamics of Fluids without Boost Symmetries\nby Jelle Hartong (Unive rsity of Edinburgh) as part of HoloTube: Applied holography webinars\n\n\n Abstract\nStandard textbook treatments of fluid dynamics assume the presen ce of a boost symmetry. This is either a Galilean boost symmetry or a Lore ntzian one and leads to the Navier-Stokes equations or their relativistic counterpart. It is however not necessary to rely on a boost symmetry as on e can treat velocity as the chemical potential associated with momentum co nservation. In fact for fluids moving through a medium one expects boost s ymmetries to be generically broken. This includes the case of scale invari ant Lifshitz fluids. In this talk I will present the general treatment of fluid dynamics without boost symmetries and I will show that there can be 10 dissipative and 6 non-dissipative transport coefficients (of which 2 ar e hydrostatic and 4 are not) for uncharged non-boost invariant fluid dynam ics. I will end with some comments regarding holographic realisations of n on-boost invariant Lifshitz fluids.\n LOCATION:https://researchseminars.org/talk/HoloTube/17/ END:VEVENT BEGIN:VEVENT SUMMARY:Danny Brattan (University of Genova) DTSTART:20200908T140000Z DTEND:20200908T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/18 DESCRIPTION:Title: Diffusion in a magnetic field\nby Danny Brattan (University of Genov a) as part of HoloTube: Applied holography webinars\n\n\nAbstract\nEven wi th the simplifying assumption of non-dynamical (external) electromagnetic fields\, magnetohydrodynamics is a technically subtle framework for unders tanding the long wavelength and low frequency regime of interacting theori es. One of these technicalities is that for many models of interdisciplina ry relevance the magnetic field is a constant in equilibrium. Intuitively however\, for momentum to be approximately conserved and enter the hydrody namic description\, the magnetic field must vanish at leading order.\n\nIn this talk I will review recent work that sheds light on some of the uniqu e features of magnetohydrodynamics in (2+1)-dimensions\, with a particular emphasis on diffusion. I will show that there is a qualitative and quanti tative improvement in matching holographic and hydrodynamic correlators if one correctly accounts for the magnetic field being non-zero in the backg round. Consequently\, I will give conclusive evidence that there is a non- zero incoherent Hall conductivity in the absence of parity violation that was missed in previous approaches. Finally\, I will discuss some ways in w hich this new approach can be applied to non-stringy systems.\n LOCATION:https://researchseminars.org/talk/HoloTube/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Paul Romatschke (University of Colorado Boulder) DTSTART:20200915T140000Z DTEND:20200915T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/19 DESCRIPTION:Title: Hydrodynamics Off Equilibrium\nby Paul Romatschke (University of Col orado Boulder) as part of HoloTube: Applied holography webinars\n\n\nAbstr act\nHaving a thermalized system is the textbook requirement for the appli cability of hydrodynamics. However\, there is mounting evidence that hydro dynamics offers a good quantitative description even in off-equilibrium si tuations. Recent applications of resurgence to relativistic fluid dynamics in the context of conformal systems is able to put the new\, generalized theory of off-equilibrium fluid dynamics on solid theoretical footing\, wi thout requiring near local equilibrium or even isotropy. This offers a tem pting explanation for\nthe ‘unreasonable success’ of hydrodynamics in describing experimental data for p+p and p+A collisions.\n LOCATION:https://researchseminars.org/talk/HoloTube/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Aldo Cotrone (University of Firenze) DTSTART:20200922T140000Z DTEND:20200922T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/20 DESCRIPTION:Title: Holographic QCD and Gravitational Waves\nby Aldo Cotrone (University of Firenze) as part of HoloTube: Applied holography webinars\n\n\nAbstrac t\nI will first review basic properties of the Sakai-Sugimoto model\, the top-down holographic theory closest to QCD. Then\, in this model I will de scribe the process of nucleation of bubbles of true vacua in the case of t wo first-order transitions: the confinement/deconfinement and chiral symme try breaking/restoration ones. Finally\, using these information\, I will present the calculation of the gravitational wave spectra generated in the se transitions\, when the Sakai-Sugimoto model is employed as a dark secto r. Prospects of detection will be discussed.\n LOCATION:https://researchseminars.org/talk/HoloTube/20/ END:VEVENT BEGIN:VEVENT SUMMARY:John McGreevy (University of California at San Diego) DTSTART:20200929T160000Z DTEND:20200929T170000Z DTSTAMP:20260422T225929Z UID:HoloTube/21 DESCRIPTION:Title: How right was Landau?\nby John McGreevy (University of California at San Diego) as part of HoloTube: Applied holography webinars\n\n\nAbstract \nThe Landau paradigm for phases of matter and transitions between them ha s been very successful. It is even more successful if we extend it to inc lude higher-form symmetries. I will discuss some applications of this way of thinking about the world. This includes revisiting the idea that the 3d Ising model is a string theory.\n(Based on work with Nabil Iqbal.)\n LOCATION:https://researchseminars.org/talk/HoloTube/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrei Starinets (University of Oxford) DTSTART:20201006T140000Z DTEND:20201006T150000Z DTSTAMP:20260422T225929Z UID:HoloTube/22 DESCRIPTION:by Andrei Starinets (University of Oxford) as part of HoloTube : Applied holography webinars\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/HoloTube/22/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrea Amoretti (University of Genoa) DTSTART:20201103T150000Z DTEND:20201103T160000Z DTSTAMP:20260422T225929Z UID:HoloTube/23 DESCRIPTION:Title: Holography\, hydrodynamics and condensed matter experiments: a critical overview\nby Andrea Amoretti (University of Genoa) as part of HoloTube : Applied holography webinars\n\n\nAbstract\nIn this talk I will review th e progress that has been done in the last year in the description of stron gly coupled condensed matter electron systems by means of hydrodynamic and holographic effective field theories\, focusing particularly on the exper imental results. Particular attention will be put on recent results on hig h temperature superconductors. In the final part of the talk I will try to emphasize open questions and possible future directions.\n LOCATION:https://researchseminars.org/talk/HoloTube/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Cindy Keeler (Arizona State University) DTSTART:20201110T170000Z DTEND:20201110T180000Z DTSTAMP:20260422T225929Z UID:HoloTube/24 DESCRIPTION:Title: Towards a general map from Navier-Stokes to Maxwell via Einstein\nby Cindy Keeler (Arizona State University) as part of HoloTube: Applied holo graphy webinars\n\n\nAbstract\nAfter a brief review of the cutoff-surface formulation of fluid-gravity duality\, we explore the “square root” of the fluid-dual metrics via the classical-double copy\, highlighting the c onstant vorticity flows and potential flows which have algebraically speci al Weyl double copy fields. We then present progress towards building the same map\, from fluid solutions to gravitational solutions to Maxwell solu tions\, for generic fluids in 2+1 dimensions. This talk is based on JHEP 0 8 (2020) 147 published with ASU students Nikhil Monga and Tucker Manton\, and forthcoming work\n LOCATION:https://researchseminars.org/talk/HoloTube/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Ben Withers (University of Southampton) DTSTART:20201117T150000Z DTEND:20201117T160000Z DTSTAMP:20260422T225929Z UID:HoloTube/25 DESCRIPTION:Title: Does the hydrodynamic expansion converge?\nby Ben Withers (Universit y of Southampton) as part of HoloTube: Applied holography webinars\n\n\nAb stract\nThis is one of the foundational questions in relativistic fluid me chanics\, and concerns the properties of a gradient expansion at large ord ers. Holographic theories provide the ideal testing ground for this questi on\, since hundreds of orders in the expansion can be obtained with relati ve ease. Famously\, the answer was found to be “No” for the Bjorken fl ow\, an expanding plasma considered in position space. In this talk I will begin by reviewing earlier work\, in which I show that the answer is inst ead “Yes” for QNM dispersion relations in momentum space\, with a radi us of convergence set by mode collisions in the complex momentum plane. I will then present recent work showing that these hitherto disjoint avenues of research are naturally unified\, and share a common underlying mechani sm governing convergence.\n LOCATION:https://researchseminars.org/talk/HoloTube/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Ya-Wen Sun (UCAS Beijing) DTSTART:20201124T150000Z DTEND:20201124T160000Z DTSTAMP:20260422T225929Z UID:HoloTube/26 DESCRIPTION:Title: Topological modes in hydrodynamics and holography\nby Ya-Wen Sun (UC AS Beijing) as part of HoloTube: Applied holography webinars\n\n\nAbstract \nIn this talk I will show that gapless modes in relativistic hydrodynamic s could become topologically nontrivial by weakly breaking the conservatio n of energy momentum tensor in a specific way. This system has topological semimetal-like crossing nodes in the spectrum of hydrodynamic modes that require the protection of a special combination of translational and boost symmetries in two spatial directions. One possible origin for the non-con servation terms of the energy momentum tensor is an external gravitational field which could be generated by a specific coordinate transformation fr om the flat spacetime. This suggests that topologically trivial modes coul d become topologically nontrivial by being observed in a special non-inert ial reference frame. Finally a holographic realization of this system will be introduced.\n LOCATION:https://researchseminars.org/talk/HoloTube/26/ END:VEVENT BEGIN:VEVENT SUMMARY:Glorioso\, Heller\, Kovtun\, Withers DTSTART:20201201T160000Z DTEND:20201201T170000Z DTSTAMP:20260422T225929Z UID:HoloTube/27 DESCRIPTION:Title: Panel on "Hydrodynamics\, out-of-equilibrium physics and holography" \nby Glorioso\, Heller\, Kovtun\, Withers as part of HoloTube: Applied hol ography webinars\n\n\nAbstract\nHosts: Navid Abbasi and Matthias Kaminski (HoloTube Team)\n\nPanelists: Pavel Kovtun (University of Victoria)\, Mich al Heller (Max Planck Institute for Gravitational Physics\, Postdam)\, Pao lo Glorioso (Stanford)\, Ben Withers (Southampton University)\n\nTitle: Di scussion about Hydrodynamics\, Out-of-Equilibrium Physics and Holography\n \nAbstract: In the recent two decades\, hydrodynamics has been systematica lly studied as a low energy effective field theory (EFT)\, which is an exp ansion into operators and their derivatives. This EFT has been extended in many directions by: including the effect of interactions\, examining the convergence of its dispersion relations\, re-summing the derivative expans ion\, connecting it to gravity\, pushing it forward to far from equilibriu m situations\, establishing its causality and stability conditions\, and d eriving it from a generating functional. In this panel discussion\, with f our experts we assess the status and prospects of this field.\n LOCATION:https://researchseminars.org/talk/HoloTube/27/ END:VEVENT BEGIN:VEVENT SUMMARY:Jorge Noronha (University of Illinois) DTSTART:20201215T150000Z DTEND:20201215T160000Z DTSTAMP:20260422T225929Z UID:HoloTube/28 DESCRIPTION:Title: Holography and the Quark-Gluon Plasma: The Next Decade\nby Jorge Nor onha (University of Illinois) as part of HoloTube: Applied holography webi nars\n\n\nAbstract\nIn this talk I will critically review the role played by holography in our current understanding of the quark-gluon plasma (QGP) formed in heavy-ion collisions. Outstanding challenges regarding the hydr odynamic behavior of the QGP will be presented\, considering the dynamical inclusion of critical phenomena and\, especially\, concerning the modelin g of the collective behavior displayed by small collision systems such as proton-nucleus and proton-proton collisions. New opportunities to improve the holographic modeling of the QGP\, in and out-of-equilibrium\, will be discussed.\n LOCATION:https://researchseminars.org/talk/HoloTube/28/ END:VEVENT BEGIN:VEVENT SUMMARY:Sayantani Bhattacharyya (NISER\, India) DTSTART:20201208T150000Z DTEND:20201208T160000Z DTSTAMP:20260422T225929Z UID:HoloTube/29 DESCRIPTION:Title: Entropy current for higher derivative theories of gravity\nby Sayant ani Bhattacharyya (NISER\, India) as part of HoloTube: Applied holography webinars\n\n\nAbstract\nWe know that black holes could be viewed as thermo dynamic ensemble of large number of microstates and therefore we could ass ociate some entropy with these objects. For Einstein gravity\, the local a rea element around any point of the black hole horizon plays the role of e ntropy density\, that satisfies the second law of thermodynamics locally a t every point on the horizon. However\, any UV complete theory of gravity\ , in its low energy limit\, will typically have higher derivative correcti ons to Einstein gravity. Black holes continue to exist for such higher der ivative theories. In this talk\, we shall show that for such theories we c ould still satisfy the second law locally on every point of the horizon\, at least when the dynamics of the black hole is of small amplitude. To see this\, we need to add a spatial entropy current to the equilibrium constr uction of Wald entropy density. This method also fixes some of the ambigui ties that arise in Wald’s construction\, for the entropy of a dynamical black hole in higher derivative theories.\n LOCATION:https://researchseminars.org/talk/HoloTube/29/ END:VEVENT BEGIN:VEVENT SUMMARY:Glorioso\, Heller\, Kovtun\, Withers DTSTART:20201210T160000Z DTEND:20201210T180000Z DTSTAMP:20260422T225929Z UID:HoloTube/30 DESCRIPTION:Title: Panel on "Hydrodynamics\, out-of-equilibrium physics and holography". Pa rt II\nby Glorioso\, Heller\, Kovtun\, Withers as part of HoloTube: Ap plied holography webinars\n\n\nAbstract\nHosts: Navid Abbasi and Matthias Kaminski (HoloTube Team)\n\nPanelists: Pavel Kovtun (University of Victori a)\, Michal Heller (Max Planck Institute for Gravitational Physics\, Postd am)\, Paolo Glorioso (Stanford)\, Ben Withers (Southampton University)\n\n Title: Discussion about Hydrodynamics\, Out-of-Equilibrium Physics and Hol ography\n\nAbstract: In the recent two decades\, hydrodynamics has been sy stematically studied as a low energy effective field theory (EFT)\, which is an expansion into operators and their derivatives. This EFT has been ex tended in many directions by: including the effect of interactions\, exami ning the convergence of its dispersion relations\, re-summing the derivati ve expansion\, connecting it to gravity\, pushing it forward to far from e quilibrium situations\, establishing its causality and stability condition s\, and deriving it from a generating functional. In this panel discussion \, with four experts we assess the status and prospects of this field.\n LOCATION:https://researchseminars.org/talk/HoloTube/30/ END:VEVENT END:VCALENDAR