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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:20260424T235209Z
UID:QASTM/1
DESCRIPTION:Title: What is the Dark Matter?\nby Stefano Profumo (Santa Cruz Institut
e for Particle Physics and University of California\, Santa Cruz\, Califor
nia\, USA) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstra
ct\nFour fifths of the matter in the universe is made of something complet
ely different from the "ordinary matter" we know and love. I will explain
why this "dark matter" is an unavoidable ingredient to explain the univers
e as we observe it\, and I will describe what the fundamental\, particle n
ature of the dark matter could possibly be. I will then give an overview o
f strategies to search for dark matter as a particle\, describe a few exam
ples of possible hints of discovery\, and outline ways forward in this exc
iting hunt.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/2
DESCRIPTION:Title: Linear in temperature resistivity in the limit of zero temperature fr
om the time reparameterization soft mode\nby Subir Sachdev (Department
Chair\, Herchel Smith Professor of Physics\, Department of Physics\, Harv
ard University\, Boston\, USA) as part of Quantum Aspects of Space-Time an
d Matter\n\nLecture held in QASTM seminar series talk.\n\nAbstract\nThe mo
st puzzling aspect of the `strange metal' behavior of correlated electron
compounds is that the linear in temperature resistivity often extends down
to low temperatures\, lower than natural microscopic energy scales. We co
nsider recently proposed deconfined critical points (or phases) in models
of electrons in large dimension lattices with random nearest-neighbor exch
ange interactions. The criticality is in the class of Sachdev-Ye-Kitaev mo
dels\, and exhibits a time reparameterization soft mode representing gravi
ty in dual holographic theories. We compute the low-temperature resistivit
y in a large M limit of models with SU(M) spin symmetry\, and find that th
e dominant temperature dependence arises from this soft mode. The resistiv
ity is linear in temperature down to zero temperature at the critical poin
t\, with a co-efficient universally proportional to the product of the res
idual resistivity and the co-efficient of the linear in temperature specif
ic heat. We argue that the time reparameterization soft mode offers a prom
ising and generic mechanism for resolving the strange metal puzzle.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/3
DESCRIPTION:Title: Thermal order in conformal theories\nby Zohar Komargodski (Simons
Center for Geometry and Physics\, Stony Brook University (SUNY Stony Broo
k)\, New York\, USA) as part of Quantum Aspects of Space-Time and Matter\n
\n\nAbstract\nIt is widely expected that at sufficiently high temperatures
order is always lost\, e.g. magnets loose their ferromagnetic properties.
We pose the question of whether this is always the case in the context of
quantum field theory in d space dimensions. More concretely\, one can ask
whether there exist critical points (CFTs) which break some global symmet
ry at arbitrary finite temperature. The most familiar CFTs do not exhibit
symmetry breaking at finite temperature\, and moreover\, in the context of
the AdS/CFT correspondence\, critical points at finite temperature are de
scribed by an uncharged black brane which obeys a no-hair theorem. Yet\, w
e 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 a
s the large rank limit (and arbitrary dimension). The large rank limit of
the vector model displays a conformal manifold\, a moduli space of vacua\,
and a deformed moduli space of vacua at finite temperature. The appropria
te Nambu-Goldstone bosons including the dilaton-like particle are identifi
ed. Using these tools we establish symmetry breaking at finite temperature
for finite small ϵ. We also prove that a large class of other fixed poin
ts\, which describe some of the most common quantum magnets\, indeed behav
e as expected and do not break any global symmetry at finite temperature.
We discuss some of the consequences of finite temperature symmetry breakin
g for the spectrum of local operators. Finally\, we propose a class of fix
ed points which appear to be possible candidates for finite temperature sy
mmetry breaking in d=2.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/4
DESCRIPTION:Title: From $\\lambda\\phi^4$ in dS to how inflation starts out of inhomogen
ous initial conditions\nby Leonardo Senatore (Institute for Theoretica
l Physics\, Stanford University\, California\, USA) as part of Quantum Asp
ects of Space-Time and Matter\n\n\nAbstract\nI will first describe how we
develop a systematic formalism to compute correlation functions of massles
s scalar fields in de Sitter space. Time permitting\, I will then show how
\, using a combination of numerical techniques as well as techniques from
differential geometry\, we are shedding light on how inflation starts out
of inhomogenous initial conditions.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/5
DESCRIPTION:Title: Bootstrapping cosmological fluctuations\nby Guilherme Leite Pimen
tel (University of Amsterdam and Leiden University\, Netherlands) as part
of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nI will describe
a new method to compute and constrain the possible shapes of primordial c
orrelation functions from inflation. This ``cosmological bootstrap” draw
s inspiration from the recent advances\nin understanding the tree-level S-
matrix in flat space\, as well as the conformal bootstrap of phase transit
ions. I will also comment on various unexplored directions for future rese
arch.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/6
DESCRIPTION:Title: Multipoint correlators in multifield cosmology: formal structure and
applications\nby Eva Silverstein (Institute for Theoretical Physics\,
Stanford University\, California\, USA) as part of Quantum Aspects of Spac
e-Time and Matter\n\n\nAbstract\nConnected N-point amplitudes in quantum f
ield theory are\nenhanced by a factor of N! inappropriate regimes of kinem
atics and\ncouplings\, but the non-perturbative analysis of this for colli
der\nphysics applications is subtle. We will start by briefly reviewing\n
this effect and related developments in large-charge sectors of\nquantum f
ield theory. We then resolve the question in the affirmative\nfor N-point
correlation functions of cosmological perturbations in\nmultifield inflat
ion and comment on its application to primordial\nnon-Gaussianity. We find
that they are calculably N!-enhanced using a\nsimple model for the mixing
of the field sectors which leads to a\nconvolution of their probability d
istributions. This effect leads to\nmodel-dependent but interesting prospe
cts for enhanced observational\nsensitivity. Additional spinoffs include
applications to primordial\nblack hole production and a new inflationary m
odel with a controlled\nresummation of derivative interactions.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/7
DESCRIPTION:Title: Challenges for physical cosmology after Planck\nby Matias Zaldarr
iaga (School of Natural Sciences\, Astrophysics and Cosmology\, Institute
for Advanced Studies\, Princeton\, USA) as part of Quantum Aspects of Spac
e-Time and Matter\n\n\nAbstract\nI will summarize the current state of phy
sical cosmology. I will describe the open questions that remain and the ch
allenges that need to be overcome to make progress.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/8
DESCRIPTION:Title: E10 Cosmology\nby Harmann Nicolai (Director and Senior Professor\
, Max Planck Institute for Gravitational Physics\, Potsdam\, Germany) as p
art of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nIn this tal
k\, I will review work done with A. Kleinschmidt (hep-th/0511290)\, where
it is shown how to construct simple exact cosmological solutions to the E1
0/K(E10)coset model by exploiting its integrability. Using the known corre
spondences with the bosonic sectors of maximal supergravity theories\, the
se exact solutions translate to exact cosmological solutions of M theory\,
first found by Townsend and Wohlfarth\, and Ohta\, exhibiting intermitten
t periods of accelerated expansion.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/9
DESCRIPTION:Title: Generating series for closed string scattering at genus one\nby A
xel Kleinschmidt (Professor and Senior Scientist\, Quantum Gravity and Uni
fied Theories Group\, Max Planck Institute for Gravitational Physics\, Pot
sdam\, Germany) as part of Quantum Aspects of Space-Time and Matter\n\n\nA
bstract\nThe low-energy limit of closed string scattering amplitudes has r
ecently received an increased amount of attention due to new connections t
o number theory and automorphic forms that I will explain in this talk. Th
e low-energy expansion for n-point scattering can be formulated in terms o
f objects called modular graph forms. Writing down these forms is easy but
analysing them less so since they satisfy an intricate web of surprising
relations. I will discuss recent progress on systematising their propertie
s based on generating function techniques and comment on a relation betwee
n open and closed string scattering. The talk is mainly based on 1911.0347
6 and 2004.05156.\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sumit R. Das (Professor\, Kentucky University\, USA)
DTSTART:20200611T133000Z
DTEND:20200611T153000Z
DTSTAMP:20260424T235209Z
UID:QASTM/10
DESCRIPTION:Title: QUANTUM QUENCH AND EMERGENT SPACE-TIMES\nby Sumit R. Das (Profes
sor\, Kentucky University\, USA) as part of Quantum Aspects of Space-Time
and Matter\n\n\nAbstract\nWe will discuss some aspects of scaling in quant
um quench and its realization in holography. We then consider quantum quen
ch in the singlet sector of the c=1 Matrix Model and map out the emergent
dual space-time. As expected the late time s[ace-time does not contain bla
ck holes. Rather\, they generically have space-like regions of large coupl
ing analogous to cosmological singularities.\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Igor R. Klebanov (Professor\, Princeton University\, USA)
DTSTART:20200615T133000Z
DTEND:20200615T153000Z
DTSTAMP:20260424T235209Z
UID:QASTM/11
DESCRIPTION:Title: Breaking of Discrete and Continuous Symmetries in SYK-like Models\nby Igor R. Klebanov (Professor\, Princeton University\, USA) as part of
Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nA Majorana fermio
n is the most elemental quantum degree of freedom – a pair of them has o
nly two quantum states. Yet\, a large number of fermions with interactions
coupling four of them at a time can exhibit interesting quantum dynamics.
Models of this kind include the Sachdev-Ye-Kitaev (SYK) model\, where the
coefficients of quartic interactions are randomly distributed\, and the T
ensor models\, where they respect continuous symmetries. These models exhi
bit approximate invariance under scaling of the time and have power law fa
ll-off of the correlation functions. In this talk we will discuss a pair o
f SYK or Tensor models coupled by the quartic interactions\, and show that
they produce a richer set of phenomena. These include a line of fixed poi
nts\, where critical exponents vary along the line and formally acquire im
aginary parts outside it. For one sign of the coupling constant\, the appr
oximate scale invariance continues to hold. For the other\, a gap opens in
the energy spectrum\, resulting in exponential fall-off of correlation fu
nctions. This is indicative of breaking of a discrete symmetry. Thus\, our
quantum mechanical model exhibits dynamical phenomena characteristic of h
igher dimensional quantum field theories. Furthermore\, the gapped phase o
f our model may be dual to a certain traversable wormhole in two-dimension
al space-time. The talk will end with a similar discussion of a pair of co
mplex SYK 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 bre
aking of one of the U(1) symmetries. This is demonstrated via an analysis
of the large N Dyson-Schwinger equations\, as well as by Exact Diagonaliza
tions of the finite N Hamiltonians.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/12
DESCRIPTION:Title: What is space? what is time? the quest for quantum gravity\nby D
aniele Oriti (Professor\, Arnold Sommerfeld Center for Theoretical Physics
• Ludwig-Maximilians-Universität (LMU) München) as part of Quantum As
pects of Space-Time and Matter\n\n\nAbstract\nWe introduce the problem of
quantum gravity\, its motivations and challenges at the conceptual as well
as physical level. In particular\, we emphasize how constructing a new co
nsistent quantum theory of the gravitational field implies deepening our u
nderstanding of the nature of space and time themselves. We overview exist
ing theoretical approaches and proposals\, and some recent results. Among
the most recent suggestions\, we illustrate the idea that spacetime itself
could be understood as an emergent notion\, and that geometry and topolog
y may find their root in quantum entanglement. Finally\, we illustrate som
e of the general points by discussing one specific quantum gravity formali
sm\, so-called group field theories\, a promising recent blend (and evolut
ion) of matrix/tensor models\, loop quantum gravity and lattice quantum gr
avity\, we discuss how cosmology could be understood\, from a quantum grav
ity perspective\, and how effective cosmological equations can be extracte
d from group field theories.\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jared Kaplan (Professor\, Johns Hopkins University\, USA)
DTSTART:20200622T133000Z
DTEND:20200622T153000Z
DTSTAMP:20260424T235209Z
UID:QASTM/13
DESCRIPTION:Title: Machine Learning and How Physicists Can Think About It\nby Jared
Kaplan (Professor\, Johns Hopkins University\, USA) as part of Quantum As
pects of Space-Time and Matter\n\n\nAbstract\nIn the last eight years ther
e has been an explosion of progress in Machine Learning. In this colloqui
um I'll explain the (very simple) ideas underlying Neural Networks\, and g
ive a few examples of their structure and current capabilities. Then I'll
survey the increasing scales of data and computation in this field\, and
make some comparisons and projections to see where it could be headed. If
time permits\, I'll also discuss my recent work on scaling laws for machi
ne learning\, and its connection to language models and GPT-3.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/14
DESCRIPTION:Title: K3 metrics\nby Max Zimet (Center for the Fundamental Laws of Nat
ure High Energy Theory Group and Black Hole initiative fellow\, Harvard Un
iversity\, Boston\, USA) as part of Quantum Aspects of Space-Time and Matt
er\n\n\nAbstract\nI will explain the recent physically motivated construct
ion of Ricci-flat K3 metrics in 2006.02435\, which gives the first example
s of Ricci-flat metrics on compact non-toroidal Calabi-Yau manifolds. I wi
ll also relate it — both physically and mathematically — to a second s
uch construction\, which is as yet not completely explicit: the missing da
ta is the BPS index of a little string theory on $T^2$. In particular\, I
will show that these discrete invariants may be extracted from the metrics
produced by the first approach.\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Aninda Sinha (CHEP\, IISC\, Bengaluru)
DTSTART:20200702T120000Z
DTEND:20200702T143000Z
DTSTAMP:20260424T235209Z
UID:QASTM/16
DESCRIPTION:Title: Bootstrapping CFTs and QFTs\nby Aninda Sinha (CHEP\, IISC\, Beng
aluru) as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\n
I will review some recent developments in the bootstrap approach towards u
nderstanding quantum field theories. I will begin by using the bootstrap t
o do epsilon expansion ala Wilson-Fisher to calculate critical exponents a
nd OPE coefficients (relevant for the 3d Ising model)—the latter being s
omething that is difficult to calculate using traditional Feynman diagram
approach. This is an example of a conformal field theory and will use tech
niques of the conformal bootstrap. Then I will discuss some recent work to
constrain the space of S-matrices for pion scattering in the standard mod
el of particle physics using the recent reincarnation of the S-matrix boot
strap. In the course\, I will also introduce and examine certain quantum i
nformation ideas which will aid us in understanding the space of S-matrice
s.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/17
DESCRIPTION:Title: String Theory Cosmology Before\, During and After Inflation\nby
Fernando Quevedo (Department of Applied Mathematics and Theoretical Physic
s (DAMTP)\, University of Cambridge\, UK) as part of Quantum Aspects of Sp
ace-Time and Matter\n\n\nAbstract\nAn overview is given of ideas incorpora
ting the inflationary scenario in string theory. The physics of moduli fie
lds from string theory is used to address questions about the origin of in
flation\, its realization\, and the physics after inflation.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/18
DESCRIPTION:Title: Eigenstate thermalization and disorder averaging in gravity\nby
James Sully (String Theory Group\, Department of Physics and Astronomy\, U
niversity of British Columbia\, Vancouver\, British Columbia\, Canada) as
part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nIt has lon
g 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 theo
ry. In that light\, one of the most surprising discoveries of the last yea
r has been that signature features of the unitary evaporation of black hol
es can already be seen within effective field theory\, albeit with the inc
lusion of 'euclidean wormholes'. However\, these novel contributions are b
est understood when the gravitational theory is not a single microscopic t
heory\, but an average over many different theories. To save unitarity mus
t we then simultaneously throw it away? I will explain how the same story
can be recovered within a single microscopic theory by thinking carefully
about the right effective theory for finite-lifetime observers.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/19
DESCRIPTION:Title: Initial Conditions for Inflation\nby Paolo Creminelli (Head\, Hi
gh Energy\, Cosmology and Astroparticle Physics (HECAP)\, The Abdus Salam
International Centre for Theoretical Physics (ICTP)\, Trieste\, Italy) as
part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nCosmic inf
lation makes the universe flat and homogeneous\, but under what conditions
inflation starts? I will discuss analytical results that show\, with weak
assumptions\, that inflation starts somewhere and some theorems in 2+1 an
d 3+1 dimensions that support the de Sitter no-hair conjecture.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/20
DESCRIPTION:Title: Typicality of Small Spins in Primordial Black Holes: from the Bekens
tein-Hawking Entropy to Gravitational Wave Observations\nby Eugenio Bi
anchi (Department of Physics and Institute for Gravitation & the Cosmos Ce
nter for 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 expl
ored phenomenological consequences to date. In this talk\, I discuss how t
he Bekenstein-Hawking entropy formula allows us to determine the probabili
ty distribution of the spin of black holes produced by the collapse of per
turbations distributed according to a general relativistic microcanonical
ensemble. I will also discuss why this ensemble is relevant for black hole
s formed in the early universe\, resulting in a population of black holes
with zero spin. In principle\, the identification of such a population at
LIGO\, Virgo\, and future gravitational wave observatories could provide t
he first observational evidence for the statistical nature of black hole e
ntropy.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/21
DESCRIPTION:Title: Scaling the Landscape: Robust EFT Implications from UV Physics\n
by Cliff Burgess (Department of Physics & Astronomy\, McMaster University
and Perimeter Institute for Theoretical Physics (PITP)\, Canada) as part o
f Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nThe phenomenon o
f decoupling is a two-edged sword: it allows a robust understanding of low
-energy physics without requiring detailed knowledge of UV completions\, b
ut by doing so it also hides any clues about these completions from prying
low-energy eyes. There is widespread interest in finding any UV diamonds
amongst the low-energy roughage\, however\, as is illustrated by the `swam
pland’ program. This program promotes the perceived difficulties in find
ing phenomenologically successful mechanisms (eg cosmic inflation) in stri
ng theory into a principle\, by asserting that some low-energy theories do
not have UV completions\, so the UV information lies in what can and cann
ot be completed. This talk takes a different approach\, arguing that EFTs
coming from weakly coupled strings enjoy a pattern of approximate scaling
symmetries\, and it is these symmetries and their pattern of breaking that
provide the robust UV information that is accessible at low energies. We
argue that these symmetries (together with other low-energy symmetries) ac
count for the widespread occurrence of no-scale supergravities in 4D strin
g vacua\, and encode attractive new mechanisms for technical naturalness.
In particular\, the symmetries themselves account for the rarity of (but d
o not predict the absence of) inflationary vacua\, and the models to which
they point include an enormously successful class of technically natural
inflationary models (not based on axions) that come with potentially testa
ble implications for the search for primordial gravity waves.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/22
DESCRIPTION:Title: The black hole information paradox\nby Vijay Balasubramanian (De
partment of Physics and Astronomy\, University of Pennsylvania School of
Arts and Sciences\, Philadelphia\, USA) as part of Quantum Aspects of Spac
e-Time and Matter\n\n\nAbstract\nFor nearly half a century\, physicists ha
ve asked whether and how we can recover information falling into black hol
es in order to guarantee the unitarity of quantum physics. In this talk\,
I will review progress we have made towards solving this puzzle. This p
rogress includes: (a) identifying the quantum gravity microstates for some
black holes\; (b) showing that information about the microstates is avail
able\, but difficult to detect\, outside the black hole\; (c) identifying
the role of chaos in scrambling information into the microstates\; (d) exp
laining the role of quantum entanglement in information encoding by black
holes and by Hawking radiation\; (e) understanding geometrization of info
rmation in gravity\; and\, finally\, (f) uncovering connections with basic
problems in information theory\, quantum computation\, and complexity th
eory.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/23
DESCRIPTION:Title: Conformal field theories are magical\nby Brian Swingle (Departme
nt of Physics and The Joint Center for Quantum Information and Computer Sc
ience\, University of Maryland\, College Park\, Maryland\, USA) as part of
Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nStabilizer states
are an important subclass of quantum states that play an important role i
n quantum error correction\, topological order\, and toy models of hologra
phy\, among many other applications. It is also important to quantify the
extent to which a given state lies beyond the stabilizer set\, a resource
known as magic. I will discuss the concept of magic and some of its measur
es in many-body physics\, focusing on a particular 1d spin chain which flo
ws to a conformal field theory in the infrared. Based on a work to appear
with Christopher White and Charles Cao.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/24
DESCRIPTION:Title: The Replica Trick in Quantum Gravity: From the Ryu-Takayanagi formul
a to Islands\nby Geoffrey Penington (Stanford Institute for Theoretica
l Physics\, Stanford University\, California\, USA) as part of Quantum Asp
ects of Space-Time and Matter\n\n\nAbstract\nStarting with the famous Lewk
owycz-Maldacena derivation of the Ryu-Takayanagi formula\, the replica tri
ck has played a central role in teaching us about entanglement and entropy
in quantum gravity. I will review these ideas\, showing how a semiclassic
al analysis leads to the quantum extremal surface prescription\, entanglem
ent wedge reconstruction\, and eventually to the recent derivations of the
Page curve in evaporating black holes.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/25
DESCRIPTION:Title: Quantum Extremal Islands Made Easy\nby Robert Myers (Perimeter I
nstitute for Theoretical Physics\, Waterloo\, Ontario\, Canada) as part of
Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nWe illustrate the
appearance of quantum extremal islands in holographic setups in higher di
mensions. We emphasize the close parallel with the behaviour of holographi
c entanglement entropy in more familiar settings.\n
LOCATION:https://stable.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:20260424T235209Z
UID:QASTM/26
DESCRIPTION:Title: A robust standard rod for cosmology\nby Ravi K. Sheth (Departmen
t of Physics and Astronomy\, University of Pennsylvania School of Arts an
d Sciences\, Philadelphia\, USA\, and Research Staff Associate at ICTP\, T
rieste\, Italy) as part of Quantum Aspects of Space-Time and Matter\n\n\nA
bstract\nBaryon Acoustic Oscillations provide a standard rod for constrain
ing cosmological distances and the expansion history of our universe over
a substantial fraction of its history. I will review the physics which mo
tivates this standard rod and summarize constraints from its use. Finally
\, I will discuss ways of making the rod more robust so that it can more e
asily be used to constrain non-standard cosmological models. This is part
icularly important given recent tension between local and distant estimate
s of the Hubble constant.\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexander Vilenkin (Professor\, Tufts University)
DTSTART:20200813T133000Z
DTEND:20200813T160000Z
DTSTAMP:20260424T235209Z
UID:QASTM/27
DESCRIPTION:Title: Black holes from cosmic inflation\nby Alexander Vilenkin (Profes
sor\, Tufts University) as part of Quantum Aspects of Space-Time and Matte
r\n\n\nAbstract\nCosmic inflation is a period of rapid\, accelerated expan
sion in the early history of the universe. Inflation explains some puzzlin
g features of the big bang that had to be postulated before and makes pred
ictions that have been confirmed by observations. In this talk\, I will ar
gue that inflation generically predicts the formation of black holes with
a very wide spectrum of masses. This effect may account for supermassive b
lack holes observed at the centers of most galaxies\, for black hole merge
rs observed by the LIGO interferometer\, and for the mysterious dark matte
r. It also has important implications for the global structure of the univ
erse.\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tadashi Takayanagi (YITP)
DTSTART:20201116T130000Z
DTEND:20201116T153000Z
DTSTAMP:20260424T235209Z
UID:QASTM/28
DESCRIPTION:Title: Recent Progresses of AdS/BCFT\nby Tadashi Takayanagi (YITP) as p
art of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nIn this lec
ture\, I would like to review recent progresses of holography for conforma
l field theories on manifolds with boundaries\, which is called as AdS/BCF
T. After we introduce the AdS/BCFT construction\, we would like to introdu
ce the holographic entanglement entropy and entanglement wedges in AdS/BCF
T\, which provided one of the important ideas behind the recent Island for
mula. Finally\, we would like to explain our recent work about codimension
two holography\, called wedge holography as an application of AdS/BCFT. \
n\nZoominar link: https://mpi-aei.zoom.us/j/97623339163\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pedro Vieira (Perimeter Institute)
DTSTART:20201123T140000Z
DTEND:20201123T163000Z
DTSTAMP:20260424T235209Z
UID:QASTM/29
DESCRIPTION:Title: Integrability in AdS/CFT\nby Pedro Vieira (Perimeter Institute)
as part of Quantum Aspects of Space-Time and Matter\n\n\nAbstract\nWe are
close to having a full solution to a quantum field theory in four dimensio
ns and its associated string theory dual. I will review some of the exciti
ng elements of this solution where Integrability and Holography play a key
role.\n\nZoominar link: https://mpi-aei.zoom.us/j/97623339163\n
LOCATION:https://stable.researchseminars.org/talk/QASTM/29/
END:VEVENT
END:VCALENDAR