BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Stefano Profumo (Santa Cruz Institute for Particle Physics and Uni versity of California\, Santa Cruz\, California\, USA) DTSTART:20200507T140000Z DTEND:20200507T153000Z DTSTAMP:20260422T214904Z UID:QASTM/1 DESCRIPTION:Title: Wh at is the Dark Matter?\nby Stefano Profumo (Santa Cruz Institute for P article Physics and University of California\, Santa Cruz\, California\, U SA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nFou r fifths of the matter in the universe is made of something completely dif ferent from the "ordinary matter" we know and love. I will explain why thi s "dark matter" is an unavoidable ingredient to explain the universe as we observe it\, and I will describe what the fundamental\, particle nature o f the dark matter could possibly be. I will then give an overview of strat egies to search for dark matter as a particle\, describe a few examples of possible hints of discovery\, and outline ways forward in this exciting h unt.\n LOCATION:https://researchseminars.org/talk/QASTM/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Subir Sachdev (Department Chair\, Herchel Smith Professor of Physi cs\, Department of Physics\, Harvard University\, Boston\, USA) DTSTART:20200514T150000Z DTEND:20200514T170000Z DTSTAMP:20260422T214904Z UID:QASTM/2 DESCRIPTION:Title: Li near in temperature resistivity in the limit of zero temperature from the time reparameterization soft mode\nby Subir Sachdev (Department Chair\ , Herchel Smith Professor of Physics\, Department of Physics\, Harvard Uni versity\, Boston\, USA) as part of Quantum Aspects of Space-Time and Matte r\n\nLecture held in QASTM seminar series talk.\n\nAbstract\nThe most puzz ling aspect of the `strange metal' behavior of correlated electron compoun ds is that the linear in temperature resistivity often extends down to low temperatures\, lower than natural microscopic energy scales. We consider recently proposed deconfined critical points (or phases) in models of elec trons in large dimension lattices with random nearest-neighbor exchange in teractions. The criticality is in the class of Sachdev-Ye-Kitaev models\, and exhibits a time reparameterization soft mode representing gravity in d ual holographic theories. We compute the low-temperature resistivity in a large M limit of models with SU(M) spin symmetry\, and find that the domin ant temperature dependence arises from this soft mode. The resistivity is linear in temperature down to zero temperature at the critical point\, wit h a co-efficient universally proportional to the product of the residual r esistivity and the co-efficient of the linear in temperature specific heat . We argue that the time reparameterization soft mode offers a promising a nd generic mechanism for resolving the strange metal puzzle.\n LOCATION:https://researchseminars.org/talk/QASTM/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Zohar Komargodski (Simons Center for Geometry and Physics\, Stony Brook University (SUNY Stony Brook)\, New York\, USA) DTSTART:20200518T160000Z DTEND:20200518T173000Z DTSTAMP:20260422T214904Z UID:QASTM/3 DESCRIPTION:Title: Th ermal order in conformal theories\nby Zohar Komargodski (Simons Center for Geometry and Physics\, Stony Brook University (SUNY Stony Brook)\, Ne w York\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbs tract\nIt is widely expected that at sufficiently high temperatures order is always lost\, e.g. magnets loose their ferromagnetic properties. We pos e the question of whether this is always the case in the context of quantu m field theory in d space dimensions. More concretely\, one can ask whethe r there exist critical points (CFTs) which break some global symmetry at a rbitrary finite temperature. The most familiar CFTs do not exhibit symmetr y breaking at finite temperature\, and moreover\, in the context of the Ad S/CFT correspondence\, critical points at finite temperature are described by an uncharged black brane which obeys a no-hair theorem. Yet\, we show that there exist CFTs which have some of their internal symmetries broken at arbitrary finite temperature. Our main example is a vector model which we study both in the epsilon expansion and arbitrary rank as well as the l arge rank limit (and arbitrary dimension). The large rank limit of the vec tor model displays a conformal manifold\, a moduli space of vacua\, and a deformed moduli space of vacua at finite temperature. The appropriate Namb u-Goldstone bosons including the dilaton-like particle are identified. Usi ng these tools we establish symmetry breaking at finite temperature for fi nite small ϵ. We also prove that a large class of other fixed points\, wh ich describe some of the most common quantum magnets\, indeed behave as ex pected and do not break any global symmetry at finite temperature. We disc uss some of the consequences of finite temperature symmetry breaking for t he spectrum of local operators. Finally\, we propose a class of fixed poin ts which appear to be possible candidates for finite temperature symmetry breaking in d=2.\n LOCATION:https://researchseminars.org/talk/QASTM/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Leonardo Senatore (Institute for Theoretical Physics\, Stanford Un iversity\, California\, USA) DTSTART:20200521T150000Z DTEND:20200521T163000Z DTSTAMP:20260422T214904Z UID:QASTM/4 DESCRIPTION:Title: Fr om $\\lambda\\phi^4$ in dS to how inflation starts out of inhomogenous ini tial conditions\nby Leonardo Senatore (Institute for Theoretical Physi cs\, Stanford University\, California\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nI will first describe how we develop a systematic formalism to compute correlation functions of massless scala r fields in de Sitter space. Time permitting\, I will then show how\, usin g a combination of numerical techniques as well as techniques from differ ential geometry\, we are shedding light on how inflation starts out of inh omogenous initial conditions.\n LOCATION:https://researchseminars.org/talk/QASTM/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Guilherme Leite Pimentel (University of Amsterdam and Leiden Unive rsity\, Netherlands) DTSTART:20200525T120000Z DTEND:20200525T133000Z DTSTAMP:20260422T214904Z UID:QASTM/5 DESCRIPTION:Title: Bo otstrapping cosmological fluctuations\nby Guilherme Leite Pimentel (Un iversity of Amsterdam and Leiden University\, Netherlands) as part of Quan tum Aspects of Space-Time and Matter\n\n\nAbstract\nI will describe a new method to compute and constrain the possible shapes of primordial correlat ion functions from inflation. This ``cosmological bootstrap” draws inspi ration from the recent advances\nin understanding the tree-level S-matrix in flat space\, as well as the conformal bootstrap of phase transitions. I will also comment on various unexplored directions for future research.\n LOCATION:https://researchseminars.org/talk/QASTM/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Eva Silverstein (Institute for Theoretical Physics\, Stanford Univ ersity\, California\, USA) DTSTART:20200528T150000Z DTEND:20200528T163000Z DTSTAMP:20260422T214904Z UID:QASTM/6 DESCRIPTION:Title: Mu ltipoint correlators in multifield cosmology: formal structure and applica tions\nby Eva Silverstein (Institute for Theoretical Physics\, Stanfor d University\, California\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nConnected N-point amplitudes in quantum field th eory are\nenhanced by a factor of N! inappropriate regimes of kinematics a nd\ncouplings\, but the non-perturbative analysis of this for collider\nph ysics applications is subtle. We will start by briefly reviewing\nthis ef fect and related developments in large-charge sectors of\nquantum field th eory. We then resolve the question in the affirmative\nfor N-point correl ation functions of cosmological perturbations in\nmultifield inflation and comment on its application to primordial\nnon-Gaussianity. We find that t hey are calculably N!-enhanced using a\nsimple model for the mixing of the field sectors which leads to a\nconvolution of their probability distribu tions. This effect leads to\nmodel-dependent but interesting prospects for enhanced observational\nsensitivity. Additional spinoffs include applica tions to primordial\nblack hole production and a new inflationary model wi th a controlled\nresummation of derivative interactions.\n LOCATION:https://researchseminars.org/talk/QASTM/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Matias Zaldarriaga (School of Natural Sciences\, Astrophysics and Cosmology\, Institute for Advanced Studies\, Princeton\, USA) DTSTART:20200601T130000Z DTEND:20200601T150000Z DTSTAMP:20260422T214904Z UID:QASTM/7 DESCRIPTION:Title: Ch allenges for physical cosmology after Planck\nby Matias Zaldarriaga (S chool of Natural Sciences\, Astrophysics and Cosmology\, Institute for Adv anced Studies\, Princeton\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nI will summarize the current state of physical c osmology. I will describe the open questions that remain and the challenge s that need to be overcome to make progress.\n LOCATION:https://researchseminars.org/talk/QASTM/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Harmann Nicolai (Director and Senior Professor\, Max Planck Instit ute for Gravitational Physics\, Potsdam\, Germany) DTSTART:20200604T120000Z DTEND:20200604T133000Z DTSTAMP:20260422T214904Z UID:QASTM/8 DESCRIPTION:Title: E1 0 Cosmology\nby Harmann Nicolai (Director and Senior Professor\, Max P lanck Institute for Gravitational Physics\, Potsdam\, Germany) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nIn this talk\, I w ill review work done with A. Kleinschmidt (hep-th/0511290)\, where it is s hown how to construct simple exact cosmological solutions to the E10/K(E10 )coset model by exploiting its integrability. Using the known corresponden ces with the bosonic sectors of maximal supergravity theories\, these exac t solutions translate to exact cosmological solutions of M theory\, first found by Townsend and Wohlfarth\, and Ohta\, exhibiting intermittent perio ds of accelerated expansion.\n LOCATION:https://researchseminars.org/talk/QASTM/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Axel Kleinschmidt (Professor and Senior Scientist\, Quantum Gravit y and Unified Theories Group\, Max Planck Institute for Gravitational Phys ics\, Potsdam\, Germany) DTSTART:20200608T130000Z DTEND:20200608T143000Z DTSTAMP:20260422T214904Z UID:QASTM/9 DESCRIPTION:Title: Ge nerating series for closed string scattering at genus one\nby Axel Kle inschmidt (Professor and Senior Scientist\, Quantum Gravity and Unified Th eories Group\, Max Planck Institute for Gravitational Physics\, Potsdam\, Germany) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract \nThe low-energy limit of closed string scattering amplitudes has recently received an increased amount of attention due to new connections to numbe r theory and automorphic forms that I will explain in this talk. The low-e nergy expansion for n-point scattering can be formulated in terms of objec ts called modular graph forms. Writing down these forms is easy but analys ing them less so since they satisfy an intricate web of surprising relatio ns. I will discuss recent progress on systematising their properties based on generating function techniques and comment on a relation between open and closed string scattering. The talk is mainly based on 1911.03476 and 2 004.05156.\n LOCATION:https://researchseminars.org/talk/QASTM/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Sumit R. Das (Professor\, Kentucky University\, USA) DTSTART:20200611T133000Z DTEND:20200611T153000Z DTSTAMP:20260422T214904Z UID:QASTM/10 DESCRIPTION:Title: Q UANTUM QUENCH AND EMERGENT SPACE-TIMES\nby Sumit R. Das (Professor\, K entucky University\, USA) as part of Quantum Aspects of Space-Time and Mat ter\n\n\nAbstract\nWe will discuss some aspects of scaling in quantum quen ch and its realization in holography. We then consider quantum quench in t he singlet sector of the c=1 Matrix Model and map out the emergent dual sp ace-time. As expected the late time s[ace-time does not contain black hole s. Rather\, they generically have space-like regions of large coupling ana logous to cosmological singularities.\n LOCATION:https://researchseminars.org/talk/QASTM/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Igor R. Klebanov (Professor\, Princeton University\, USA) DTSTART:20200615T133000Z DTEND:20200615T153000Z DTSTAMP:20260422T214904Z UID:QASTM/11 DESCRIPTION:Title: B reaking of Discrete and Continuous Symmetries in SYK-like Models\nby I gor R. Klebanov (Professor\, Princeton University\, USA) as part of Quantu m Aspects of Space-Time and Matter\n\n\nAbstract\nA Majorana fermion is th e most elemental quantum degree of freedom – a pair of them has only two quantum states. Yet\, a large number of fermions with interactions coupli ng four of them at a time can exhibit interesting quantum dynamics. Models of this kind include the Sachdev-Ye-Kitaev (SYK) model\, where the coeffi cients of quartic interactions are randomly distributed\, and the Tensor m odels\, where they respect continuous symmetries. These models exhibit app roximate invariance under scaling of the time and have power law fall-off of the correlation functions. In this talk we will discuss a pair of SYK o r Tensor models coupled by the quartic interactions\, and show that they p roduce a richer set of phenomena. These include a line of fixed points\, w here critical exponents vary along the line and formally acquire imaginary parts outside it. For one sign of the coupling constant\, the approximate scale invariance continues to hold. For the other\, a gap opens in the en ergy spectrum\, resulting in exponential fall-off of correlation functions . This is indicative of breaking of a discrete symmetry. Thus\, our quantu m mechanical model exhibits dynamical phenomena characteristic of higher d imensional quantum field theories. Furthermore\, the gapped phase of our m odel may be dual to a certain traversable wormhole in two-dimensional spac e-time. The talk will end with a similar discussion of a pair of complex S YK models coupled by a quartic interaction which preserves the U(1) x U(1) symmetry. For a range of parameters\, this model gives rise to breaking o f one of the U(1) symmetries. This is demonstrated via an analysis of the large N Dyson-Schwinger equations\, as well as by Exact Diagonalizations o f the finite N Hamiltonians.\n LOCATION:https://researchseminars.org/talk/QASTM/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Daniele Oriti (Professor\, Arnold Sommerfeld Center for Theoretica l Physics • Ludwig-Maximilians-Universität (LMU) München) DTSTART:20200618T120000Z DTEND:20200618T140000Z DTSTAMP:20260422T214904Z UID:QASTM/12 DESCRIPTION:Title: W hat is space? what is time? the quest for quantum gravity\nby Daniele Oriti (Professor\, Arnold Sommerfeld Center for Theoretical Physics • Lu dwig-Maximilians-Universität (LMU) München) as part of Quantum Aspects o f Space-Time and Matter\n\n\nAbstract\nWe introduce the problem of quantum gravity\, its motivations and challenges at the conceptual as well as phy sical level. In particular\, we emphasize how constructing a new consisten t quantum theory of the gravitational field implies deepening our understa nding of the nature of space and time themselves. We overview existing the oretical approaches and proposals\, and some recent results. Among the mos t recent suggestions\, we illustrate the idea that spacetime itself could be understood as an emergent notion\, and that geometry and topology may f ind their root in quantum entanglement. Finally\, we illustrate some of th e general points by discussing one specific quantum gravity formalism\, so -called group field theories\, a promising recent blend (and evolution) of matrix/tensor models\, loop quantum gravity and lattice quantum gravity\, we discuss how cosmology could be understood\, from a quantum gravity per spective\, and how effective cosmological equations can be extracted from group field theories.\n LOCATION:https://researchseminars.org/talk/QASTM/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Jared Kaplan (Professor\, Johns Hopkins University\, USA) DTSTART:20200622T133000Z DTEND:20200622T153000Z DTSTAMP:20260422T214904Z UID:QASTM/13 DESCRIPTION:Title: M achine Learning and How Physicists Can Think About It\nby Jared Kaplan (Professor\, Johns Hopkins University\, USA) as part of Quantum Aspects o f Space-Time and Matter\n\n\nAbstract\nIn the last eight years there has b een an explosion of progress in Machine Learning. In this colloquium I'll explain the (very simple) ideas underlying Neural Networks\, and give a f ew examples of their structure and current capabilities. Then I'll survey the increasing scales of data and computation in this field\, and make so me comparisons and projections to see where it could be headed. If time p ermits\, I'll also discuss my recent work on scaling laws for machine lear ning\, and its connection to language models and GPT-3.\n LOCATION:https://researchseminars.org/talk/QASTM/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Max Zimet (Center for the Fundamental Laws of Nature High Energy T heory Group and Black Hole initiative fellow\, Harvard University\, Boston \, USA) DTSTART:20200625T130000Z DTEND:20200625T150000Z DTSTAMP:20260422T214904Z UID:QASTM/14 DESCRIPTION:Title: K 3 metrics\nby Max Zimet (Center for the Fundamental Laws of Nature Hig h Energy Theory Group and Black Hole initiative fellow\, Harvard Universit y\, Boston\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\ nAbstract\nI will explain the recent physically motivated construction of Ricci-flat K3 metrics in 2006.02435\, which gives the first examples of Ri cci-flat metrics on compact non-toroidal Calabi-Yau manifolds. I will also relate it — both physically and mathematically — to a second such con struction\, which is as yet not completely explicit: the missing data is t he BPS index of a little string theory on $T^2$. In particular\, I will sh ow that these discrete invariants may be extracted from the metrics produc ed by the first approach.\n LOCATION:https://researchseminars.org/talk/QASTM/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Aninda Sinha (CHEP\, IISC\, Bengaluru) DTSTART:20200702T120000Z DTEND:20200702T143000Z DTSTAMP:20260422T214904Z UID:QASTM/16 DESCRIPTION:Title: B ootstrapping CFTs and QFTs\nby Aninda Sinha (CHEP\, IISC\, Bengaluru) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nI will review some recent developments in the bootstrap approach towards understa nding quantum field theories. I will begin by using the bootstrap to do ep silon expansion ala Wilson-Fisher to calculate critical exponents and OPE coefficients (relevant for the 3d Ising model)—the latter being somethin g that is difficult to calculate using traditional Feynman diagram approac h. This is an example of a conformal field theory and will use techniques of the conformal bootstrap. Then I will discuss some recent work to constr ain the space of S-matrices for pion scattering in the standard model of p article physics using the recent reincarnation of the S-matrix bootstrap. In the course\, I will also introduce and examine certain quantum informat ion ideas which will aid us in understanding the space of S-matrices.\n LOCATION:https://researchseminars.org/talk/QASTM/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Fernando Quevedo (Department of Applied Mathematics and Theoretica l Physics (DAMTP)\, University of Cambridge\, UK) DTSTART:20200629T120000Z DTEND:20200629T143000Z DTSTAMP:20260422T214904Z UID:QASTM/17 DESCRIPTION:Title: S tring Theory Cosmology Before\, During and After Inflation\nby Fernand o Quevedo (Department of Applied Mathematics and Theoretical Physics (DAMT P)\, University of Cambridge\, UK) as part of Quantum Aspects of Space-Tim e and Matter\n\n\nAbstract\nAn overview is given of ideas incorporating th e inflationary scenario in string theory. The physics of moduli fields fro m string theory is used to address questions about the origin of inflation \, its realization\, and the physics after inflation.\n LOCATION:https://researchseminars.org/talk/QASTM/17/ END:VEVENT BEGIN:VEVENT SUMMARY:James Sully (String Theory Group\, Department of Physics and Astro nomy\, University of British Columbia\, Vancouver\, British Columbia\, Can ada) DTSTART:20200706T150000Z DTEND:20200706T173000Z DTSTAMP:20260422T214904Z UID:QASTM/18 DESCRIPTION:Title: E igenstate thermalization and disorder averaging in gravity\nby James S ully (String Theory Group\, Department of Physics and Astronomy\, Universi ty of British Columbia\, Vancouver\, British Columbia\, Canada) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nIt has long been believed that progress in understanding the black hole information paradox would require coming to terms with microscopic details of quantum gravity ---something beyond the reach of semiclassical effective field theory. In that light\, one of the most surprising discoveries of the last year has b een that signature features of the unitary evaporation of black holes can already be seen within effective field theory\, albeit with the inclusion of 'euclidean wormholes'. However\, these novel contributions are best und erstood when the gravitational theory is not a single microscopic theory\, but an average over many different theories. To save unitarity must we th en simultaneously throw it away? I will explain how the same story can be recovered within a single microscopic theory by thinking carefully about t he right effective theory for finite-lifetime observers.\n LOCATION:https://researchseminars.org/talk/QASTM/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Paolo Creminelli (Head\, High Energy\, Cosmology and Astroparticle Physics (HECAP)\, The Abdus Salam International Centre for Theoretical Ph ysics (ICTP)\, Trieste\, Italy) DTSTART:20200709T120000Z DTEND:20200709T143000Z DTSTAMP:20260422T214904Z UID:QASTM/19 DESCRIPTION:Title: I nitial Conditions for Inflation\nby Paolo Creminelli (Head\, High Ener gy\, Cosmology and Astroparticle Physics (HECAP)\, The Abdus Salam Interna tional Centre for Theoretical Physics (ICTP)\, Trieste\, Italy) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nCosmic inflation makes the universe flat and homogeneous\, but under what conditions inflat ion starts? I will discuss analytical results that show\, with weak assump tions\, that inflation starts somewhere and some theorems in 2+1 and 3+1 d imensions that support the de Sitter no-hair conjecture.\n LOCATION:https://researchseminars.org/talk/QASTM/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Eugenio Bianchi (Department of Physics and Institute for Gravitati on & the Cosmos Center for Fundamental Theory\, Pennsylvania State Univers ity\, Pennsylvania\, USA) DTSTART:20200713T130000Z DTEND:20200713T153000Z DTSTAMP:20260422T214904Z UID:QASTM/20 DESCRIPTION:Title: T ypicality of Small Spins in Primordial Black Holes: from the Bekenstein-Ha wking Entropy to Gravitational Wave Observations\nby Eugenio Bianchi ( Department of Physics and Institute for Gravitation & the Cosmos Center fo r Fundamental Theory\, Pennsylvania State University\, Pennsylvania\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nBlack hole entropy is a robust prediction of quantum gravity with no explored ph enomenological consequences to date. In this talk\, I discuss how the Beke nstein-Hawking entropy formula allows us to determine the probability dist ribution of the spin of black holes produced by the collapse of perturbati ons distributed according to a general relativistic microcanonical ensembl e. I will also discuss why this ensemble is relevant for black holes forme d in the early universe\, resulting in a population of black holes with ze ro spin. In principle\, the identification of such a population at LIGO\, Virgo\, and future gravitational wave observatories could provide the firs t observational evidence for the statistical nature of black hole entropy. \n LOCATION:https://researchseminars.org/talk/QASTM/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Cliff Burgess (Department of Physics & Astronomy\, McMaster Univer sity and Perimeter Institute for Theoretical Physics (PITP)\, Canada) DTSTART:20200716T133000Z DTEND:20200716T160000Z DTSTAMP:20260422T214904Z UID:QASTM/21 DESCRIPTION:Title: S caling the Landscape: Robust EFT Implications from UV Physics\nby Clif f Burgess (Department of Physics & Astronomy\, McMaster University and Per imeter Institute for Theoretical Physics (PITP)\, Canada) as part of Quant um Aspects of Space-Time and Matter\n\n\nAbstract\nThe phenomenon of decou pling is a two-edged sword: it allows a robust understanding of low-energy physics without requiring detailed knowledge of UV completions\, but by d oing so it also hides any clues about these completions from prying low-en ergy eyes. There is widespread interest in finding any UV diamonds amongst the low-energy roughage\, however\, as is illustrated by the `swampland ’ program. This program promotes the perceived difficulties in finding p henomenologically successful mechanisms (eg cosmic inflation) in string th eory into a principle\, by asserting that some low-energy theories do not have UV completions\, so the UV information lies in what can and cannot be completed. This talk takes a different approach\, arguing that EFTs comin g from weakly coupled strings enjoy a pattern of approximate scaling symme tries\, and it is these symmetries and their pattern of breaking that prov ide the robust UV information that is accessible at low energies. We argue that these symmetries (together with other low-energy symmetries) account for the widespread occurrence of no-scale supergravities in 4D string vac ua\, and encode attractive new mechanisms for technical naturalness. In pa rticular\, the symmetries themselves account for the rarity of (but do not predict the absence of) inflationary vacua\, and the models to which they point include an enormously successful class of technically natural infla tionary models (not based on axions) that come with potentially testable i mplications for the search for primordial gravity waves.\n LOCATION:https://researchseminars.org/talk/QASTM/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Vijay Balasubramanian (Department of Physics and Astronomy\, Univ ersity of Pennsylvania School of Arts and Sciences\, Philadelphia\, USA) DTSTART:20200720T133000Z DTEND:20200720T160000Z DTSTAMP:20260422T214904Z UID:QASTM/22 DESCRIPTION:Title: T he black hole information paradox\nby Vijay Balasubramanian (Departmen t of Physics and Astronomy\, University of Pennsylvania School of Arts an d Sciences\, Philadelphia\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nFor nearly half a century\, physicists have aske d whether and how we can recover information falling into black holes in o rder to guarantee the unitarity of quantum physics. In this talk\, I will review progress we have made towards solving this puzzle. This progress includes: (a) identifying the quantum gravity microstates for some black holes\; (b) showing that information about the microstates is available\, but difficult to detect\, outside the black hole\; (c) identifying the rol e of chaos in scrambling information into the microstates\; (d) explaining the role of quantum entanglement in information encoding by black holes a nd by Hawking radiation\; (e) understanding geometrization of information in gravity\; and\, finally\, (f) uncovering connections with basic proble ms in information theory\, quantum computation\, and complexity theory.\n LOCATION:https://researchseminars.org/talk/QASTM/22/ END:VEVENT BEGIN:VEVENT SUMMARY:Brian Swingle (Department of Physics and The Joint Center for Quan tum Information and Computer Science\, University of Maryland\, College Pa rk\, Maryland\, USA) DTSTART:20200723T130000Z DTEND:20200723T153000Z DTSTAMP:20260422T214904Z UID:QASTM/23 DESCRIPTION:Title: C onformal field theories are magical\nby Brian Swingle (Department of P hysics and The Joint Center for Quantum Information and Computer Science\, University of Maryland\, College Park\, Maryland\, USA) as part of Quantu m Aspects of Space-Time and Matter\n\n\nAbstract\nStabilizer states are an important subclass of quantum states that play an important role in quant um error correction\, topological order\, and toy models of holography\, a mong many other applications. It is also important to quantify the extent to which a given state lies beyond the stabilizer set\, a resource known a s magic. I will discuss the concept of magic and some of its measures in m any-body physics\, focusing on a particular 1d spin chain which flows to a conformal field theory in the infrared. Based on a work to appear with Ch ristopher White and Charles Cao.\n LOCATION:https://researchseminars.org/talk/QASTM/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Geoffrey Penington (Stanford Institute for Theoretical Physics\, S tanford University\, California\, USA) DTSTART:20200727T150000Z DTEND:20200727T173000Z DTSTAMP:20260422T214904Z UID:QASTM/24 DESCRIPTION:Title: T he Replica Trick in Quantum Gravity: From the Ryu-Takayanagi formula to Is lands\nby Geoffrey Penington (Stanford Institute for Theoretical Physi cs\, Stanford University\, California\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nStarting with the famous Lewkowycz-M aldacena derivation of the Ryu-Takayanagi formula\, the replica trick has played a central role in teaching us about entanglement and entropy in qua ntum gravity. I will review these ideas\, showing how a semiclassical anal ysis leads to the quantum extremal surface prescription\, entanglement wed ge reconstruction\, and eventually to the recent derivations of the Page c urve in evaporating black holes.\n LOCATION:https://researchseminars.org/talk/QASTM/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Robert Myers (Perimeter Institute for Theoretical Physics\, Waterl oo\, Ontario\, Canada) DTSTART:20200730T133000Z DTEND:20200730T160000Z DTSTAMP:20260422T214904Z UID:QASTM/25 DESCRIPTION:Title: Q uantum Extremal Islands Made Easy\nby Robert Myers (Perimeter Institut e for Theoretical Physics\, Waterloo\, Ontario\, Canada) as part of Quantu m Aspects of Space-Time and Matter\n\n\nAbstract\nWe illustrate the appear ance of quantum extremal islands in holographic setups in higher dimension s. We emphasize the close parallel with the behaviour of holographic entan glement entropy in more familiar settings.\n LOCATION:https://researchseminars.org/talk/QASTM/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Ravi K. Sheth (Department of Physics and Astronomy\, University o f Pennsylvania School of Arts and Sciences\, Philadelphia\, USA\, and Rese arch Staff Associate at ICTP\, Trieste\, Italy) DTSTART:20200731T133000Z DTEND:20200731T160000Z DTSTAMP:20260422T214904Z UID:QASTM/26 DESCRIPTION:Title: A robust standard rod for cosmology\nby Ravi K. Sheth (Department of Ph ysics and Astronomy\, University of Pennsylvania School of Arts and Scien ces\, Philadelphia\, USA\, and Research Staff Associate at ICTP\, Trieste\ , Italy) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract \nBaryon Acoustic Oscillations provide a standard rod for constraining cos mological distances and the expansion history of our universe over a subst antial fraction of its history. I will review the physics which motivates this standard rod and summarize constraints from its use. Finally\, I wi ll discuss ways of making the rod more robust so that it can more easily b e used to constrain non-standard cosmological models. This is particularl y important given recent tension between local and distant estimates of th e Hubble constant.\n LOCATION:https://researchseminars.org/talk/QASTM/26/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexander Vilenkin (Professor\, Tufts University) DTSTART:20200813T133000Z DTEND:20200813T160000Z DTSTAMP:20260422T214904Z UID:QASTM/27 DESCRIPTION:Title: B lack holes from cosmic inflation\nby Alexander Vilenkin (Professor\, T ufts University) as part of Quantum Aspects of Space-Time and Matter\n\n\n Abstract\nCosmic inflation is a period of rapid\, accelerated expansion in the early history of the universe. Inflation explains some puzzling featu res of the big bang that had to be postulated before and makes predictions that have been confirmed by observations. In this talk\, I will argue tha t inflation generically predicts the formation of black holes with a very wide spectrum of masses. This effect may account for supermassive black ho les observed at the centers of most galaxies\, for black hole mergers obse rved by the LIGO interferometer\, and for the mysterious dark matter. It a lso has important implications for the global structure of the universe.\n LOCATION:https://researchseminars.org/talk/QASTM/27/ END:VEVENT BEGIN:VEVENT SUMMARY:Tadashi Takayanagi (YITP) DTSTART:20201116T130000Z DTEND:20201116T153000Z DTSTAMP:20260422T214904Z UID:QASTM/28 DESCRIPTION:Title: R ecent Progresses of AdS/BCFT\nby Tadashi Takayanagi (YITP) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nIn this lecture\, I would like to review recent progresses of holography for conformal field theories on manifolds with boundaries\, which is called as AdS/BCFT. Afte r we introduce the AdS/BCFT construction\, we would like to introduce the holographic entanglement entropy and entanglement wedges in AdS/BCFT\, whi ch provided one of the important ideas behind the recent Island formula. F inally\, we would like to explain our recent work about codimension two ho lography\, called wedge holography as an application of AdS/BCFT. \n\nZoom inar link: https://mpi-aei.zoom.us/j/97623339163\n LOCATION:https://researchseminars.org/talk/QASTM/28/ END:VEVENT BEGIN:VEVENT SUMMARY:Pedro Vieira (Perimeter Institute) DTSTART:20201123T140000Z DTEND:20201123T163000Z DTSTAMP:20260422T214904Z UID:QASTM/29 DESCRIPTION:Title: I ntegrability in AdS/CFT\nby Pedro Vieira (Perimeter Institute) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nWe are close t o having a full solution to a quantum field theory in four dimensions and its associated string theory dual. I will review some of the exciting elem ents of this solution where Integrability and Holography play a key role.\ n\nZoominar link: https://mpi-aei.zoom.us/j/97623339163\n LOCATION:https://researchseminars.org/talk/QASTM/29/ END:VEVENT END:VCALENDAR