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BEGIN:VEVENT
SUMMARY:Vincent Van Hemelryck (KU Leuven)
DTSTART;VALUE=DATE-TIME:20211110T150000Z
DTEND;VALUE=DATE-TIME:20211110T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/1
DESCRIPTION:Title: Sca
le-separated AdS4 vacua of IIA orientifolds and M-theory\nby Vincent V
an Hemelryck (KU Leuven) as part of AnLy Strings and Fields online seminar
s\n\n\nAbstract\nObtaining string compactifications where the KK scale is
much higher than the cosmological constant scale is quite challenging. Suc
h a separation of scales is however necessary for the theory to be genuine
ly lower-dimensional. In massive type IIA string theory there are such sca
le-separated vacua\, e.g. the DGKT AdS4 solutions. It has been shown recen
tly that the classical orientifold backreaction in these vacua can be tune
d small. In this talk\, I show that massless IIA on the other hand allows
both weakly and strongly coupled AdS4 vacua that exhibit scale separation
and for which the backreaction can be tuned small as well. I will give evi
dence that the strongly coupled solutions can be lifted to scale separated
and sourceless (but classically singular) geometries in 11D supergravity.
\n
LOCATION:https://researchseminars.org/talk/AnLy/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Giuseppe Dibitetto (Padua U.)
DTSTART;VALUE=DATE-TIME:20211124T150000Z
DTEND;VALUE=DATE-TIME:20211124T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/2
DESCRIPTION:Title: Non
-perturbative instability of mIIA on AdS_4 x S^6\nby Giuseppe Dibitett
o (Padua U.) as part of AnLy Strings and Fields online seminars\n\n\nAbstr
act\nI will start by reviewing the physics of KK bubbles and their higher-
dimensional generalizations. Secondly\, I will move to discussing slightly
more general situations where the shrinking modulus is the string couplin
g. Subsequently\, I will focus on cases where a Freund-Rubin flux is prese
nt\, thus leading to the necessity of introducing a source. Finally\, I wi
ll discuss the case of massive IIA on a 6-sphere as an explicit realizatio
n of the aforementioned mechanism and provide an appropriate physical inte
rpretation.\n
LOCATION:https://researchseminars.org/talk/AnLy/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivonne Zavala (Swansea U.)
DTSTART;VALUE=DATE-TIME:20211208T150000Z
DTEND;VALUE=DATE-TIME:20211208T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/3
DESCRIPTION:Title: Mul
tifield inflation in string theory and supergravity\nby Ivonne Zavala
(Swansea U.) as part of AnLy Strings and Fields online seminars\n\n\nAbstr
act\nMultifield inflation arises naturally in supergravity and string theo
ry models. When several scalars are active during inflation\, the eta-prob
lem may be circumvented\, while new trajectories with large turns can aris
e\, with interesting observational consequences. I will discuss the prosp
ects of realising these features in supergravity and string theory models
of inflation.\n
LOCATION:https://researchseminars.org/talk/AnLy/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Edgar Shaghoulian (Cornell U.)
DTSTART;VALUE=DATE-TIME:20220112T150000Z
DTEND;VALUE=DATE-TIME:20220112T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/4
DESCRIPTION:Title: The
central dogma and cosmological horizons\nby Edgar Shaghoulian (Cornel
l U.) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\nTh
e central dogma of black hole physics – which says that from the outside
a black hole can be described in terms of a quantum system with exp(Area/
4G) states evolving unitarily – has recently been supported by computati
ons indicating that the interior of the black hole is encoded in the Hawki
ng radiation of the exterior. In this paper\, we probe whether such a dogm
a for cosmological horizons has any support from similar computations. The
fact that the de Sitter bifurcation surface is a minimax surface (instead
of a maximin surface) causes problems with this interpretation when tryin
g to import calculations analogous to the AdS case. This suggests anchorin
g extremal surfaces to the horizon itself\, where we formulate a two-sided
extremization prescription and find answers consistent with general expec
tations for a quantum theory of de Sitter space: vanishing total entropy\,
an entropy of A/4G when restricting to a single static patch\, an entropy
of a subregion of the horizon which grows with the region size and threat
ens the central dogma until an island-like transition at half the horizon
size when the entanglement wedge becomes the entire static patch interior\
, and a de Sitter version of the Hartman-Maldacena transition.\n
LOCATION:https://researchseminars.org/talk/AnLy/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francesc Cunillera (U. Nottingham)
DTSTART;VALUE=DATE-TIME:20220209T150000Z
DTEND;VALUE=DATE-TIME:20220209T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/5
DESCRIPTION:Title: Qui
ntessence and the Swampland: tales of parametric and numerical control
\nby Francesc Cunillera (U. Nottingham) as part of AnLy Strings and Fields
online seminars\n\n\nAbstract\nWe provide a detailed discussion of the ma
in theoretical and phenomenological challenges of quintessence model build
ing in any parametric or numerically controlled regime of the moduli space
of string theory. We argue that a working quintessence model requires a l
eading order non-supersymmetric (near) Minkowski vacuum with an axionic fl
at direction away from the boundary of moduli space. This axion\, when lif
ted by subdominant non-perturbative effects\, could drive hilltop quintess
ence only for very tuned initial conditions and a very low inflationary sc
ale.\nOur analysis has a twofold implication: (1) Scenarios which are in a
greement with the swampland dS conjecture\, like AdS and supersymmetric Mi
nkowski vacua\, as well as runaways\, cannot allow for phenomenologically
viable quintessence with full computational control. This raises doubts on
the validity of the swampland dS conjecture since it would imply a strong
tension between quantum gravity and observations. (2) If data will prefer
dynamical dark energy\, axion models based on misalignment mechanisms loo
k more promising than hilltop scenarios which are very contrived.\n
LOCATION:https://researchseminars.org/talk/AnLy/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Junghans (Harvard U.)
DTSTART;VALUE=DATE-TIME:20220302T150000Z
DTEND;VALUE=DATE-TIME:20220302T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/6
DESCRIPTION:Title: (Ca
ncelled) Corrections to the LARGE-Volume Scenario\nby Daniel Junghans
(Harvard U.) as part of AnLy Strings and Fields online seminars\n\n\nAbstr
act\nWe argue that de Sitter vacua in the LARGE-volume scenario of type II
B string theory are vulnerable to various unsuppressed curvature\, warping
and g_s corrections. We discuss how these corrections affect the moduli v
evs\, the vacuum energy and the moduli masses. Our analysis reveals that t
he corrections are parametrically larger in the relevant expressions than
one might have guessed from their suppression in the off-shell potential.
Some corrections appear without any parametric suppression at all\, which
makes them particularly dangerous for candidate de Sitter vacua. Other typ
es of corrections can in principle be made small for appropriate parameter
choices. However\, we show in an explicit model that this is never possib
le for all corrections at the same time when the vacuum energy is positive
.\n
LOCATION:https://researchseminars.org/talk/AnLy/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marios Petropoulos (Ecole Polytechnique\, CPHT)
DTSTART;VALUE=DATE-TIME:20220330T140000Z
DTEND;VALUE=DATE-TIME:20220330T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/7
DESCRIPTION:Title: Car
rollian fluids and Chthonian versus celestial holography\nby Marios Pe
tropoulos (Ecole Polytechnique\, CPHT) as part of AnLy Strings and Fields
online seminars\n\n\nAbstract\nThe usual approach of fluid/gravity corresp
ondence coincides with solving Einstein's equations in a generalized "inco
mplete Newman-Unti gauge". In this framework\, the asymptotic symmetry gro
up is bigger and accounts for the boundary-fluid hydrodynamic frame invari
ance. The latter pattern holds both for Einstein and Ricci-flat spacetimes
\, dual to relativistic and Carrollian fluids\, respectively. This is a co
ncrete starting point for approaching flat holography and understanding th
e role of the BMS group on the dual boundary theory. It suggests that the
latter might be non-local in order to account for the infinite Chthonian d
egrees of freedom\, as opposed to the celestial proposal.\n
LOCATION:https://researchseminars.org/talk/AnLy/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Joseph Conlon (Oxford U.)
DTSTART;VALUE=DATE-TIME:20220316T151500Z
DTEND;VALUE=DATE-TIME:20220316T161500Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/8
DESCRIPTION:Title: Hol
ographic Questions About Moduli Stabilisation\nby Joseph Conlon (Oxfor
d U.) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\nMo
duli stabilisation is an important and fundamental question in string theo
ry as it is a precursor to constructing semi-realistic string vacua. I des
cribe work over the last few years aiming at examining moduli stabilised v
acua from a holographic perspective\, studying in particular LVS in IIB an
d DGKT in IIA. In scale separated limits of large volumes and weak couplin
g\, the conformal dimensions of dual operators approach fixed values that
are independent of fluxes and many other microscopic aspects of the constr
uctions. A further intriguing property is the existence of integer conform
al dimensions for DGKT vacua\, although the origin of these integers is my
sterious.\n
LOCATION:https://researchseminars.org/talk/AnLy/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gianguido Dall'Agata (Padua U.)
DTSTART;VALUE=DATE-TIME:20220413T140000Z
DTEND;VALUE=DATE-TIME:20220413T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/9
DESCRIPTION:Title: Sup
ergravity and the weak gravity conjecture\nby Gianguido Dall'Agata (Pa
dua U.) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\n
I will show how the weak gravity conjecture applied to 4-dimensional super
gravity theories can be very powerful in constraining which models can be
realistically obtained as low-energy effective theories of string theory.
In particular\, I will discuss how we can obtain rather general and strong
constraints on scale separation between the lower and higher dimensional
theory and how most models with positive energy critical points cannot hav
e a consistent string theory origin.\n
LOCATION:https://researchseminars.org/talk/AnLy/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Erik Plauschinn (Utrecht U.)
DTSTART;VALUE=DATE-TIME:20220511T140000Z
DTEND;VALUE=DATE-TIME:20220511T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/10
DESCRIPTION:Title: Th
e tadpole conjecture in asymptotic limits\nby Erik Plauschinn (Utrecht
U.) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\nSup
erstring theory is defined in ten space-time dimensions. In order to conne
ct it to physics in four dimensions one typically has to compactify the th
eory and satisfy a number consistency conditions. One of them is the tadpo
le cancellation condition. Recently\, Bena\, Blabäck\, Grana\, and Lüst
made a "tadpole conjecture" which - if true - would imply that many naivel
y-allowed (flux-)compactifications are inconsistent. \nIn the first part o
f the talk I will explain and illustrate the tadpole conjecture. In the se
cond part I present arguments towards a proof of the conjecture in asympto
tic limits using the framework of asymptotic Hodge theory.\n
LOCATION:https://researchseminars.org/talk/AnLy/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Romain Ruzziconi (TU Wien)
DTSTART;VALUE=DATE-TIME:20220525T140000Z
DTEND;VALUE=DATE-TIME:20220525T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/11
DESCRIPTION:Title: A
Carrollian Perspective on Celestial Holography\nby Romain Ruzziconi (T
U Wien) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\n
I will present a holographic description of gravity in 4d asymptotically f
lat spacetime in terms of a 3d sourced conformal Carrollian field theory.
The external sources encode the leaks of gravitational radiation at null i
nfinity. The Ward identities of this theory are shown to reproduce those o
f the 2d celestial CFT after relating Carrollian to celestial operators. T
his suggests a new set of interplays between gravity in asymptotically fla
t spacetime\, sourced conformal Carrollian field theory and celestial CFT.
\n\n\nBased on: https://arxiv.org/abs/2202.04702\n
LOCATION:https://researchseminars.org/talk/AnLy/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michela Petrini (LPTHE Paris)
DTSTART;VALUE=DATE-TIME:20220608T140000Z
DTEND;VALUE=DATE-TIME:20220608T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/12
DESCRIPTION:Title: A
systematic approach to consistent truncations\nby Michela Petrini (LPT
HE Paris) as part of AnLy Strings and Fields online seminars\n\n\nAbstract
\nIn this talk I will discuss how generalised geometry provides a systemat
ic way to construct and classify consistent truncations to different dimen
sions and with different amount of supersymmetry. As an example I will app
ly this formalism to the classification of N=2 gauged supergravity in 5 fi
ve dimensions that can be obtained as consistent truncations of type IIB o
r M theory.\n
LOCATION:https://researchseminars.org/talk/AnLy/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Oscar Loaiza-Brito (Guanajuato U.)
DTSTART;VALUE=DATE-TIME:20220622T140000Z
DTEND;VALUE=DATE-TIME:20220622T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/13
DESCRIPTION:Title: Ad
S and dS vacua from torsion and non-BPS states\nby Oscar Loaiza-Brito
(Guanajuato U.) as part of AnLy Strings and Fields online seminars\n\n\nAb
stract\nWe look for minimal conditions to construct stable Anti de Sitter
and de Sitter vacua from type IIB String theory compactification on Kähle
r manifolds with torsion in the presence of O3-planes. This allows contrib
utions to the scalar potential from the five-form flux and from D5-branes
wrapping torsional cycles -interpreted as non-BPS states carrying discrete
Z_2 charge and classified by K-theory- which in turn leads to the constru
ction of AdS and dS vacua respectively. We shall discuss some constraints
on the configuration as well as possible sources of instabilities.\n
LOCATION:https://researchseminars.org/talk/AnLy/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Claude Duhr (Bonn U.)
DTSTART;VALUE=DATE-TIME:20221005T140000Z
DTEND;VALUE=DATE-TIME:20221005T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/14
DESCRIPTION:Title: 2D
fishnet integrals and Calabi-Yau geometries\nby Claude Duhr (Bonn U.)
as part of AnLy Strings and Fields online seminars\n\n\nAbstract\nWe argu
e that Yangian-invariant l-loop fishnet integrals in 2 dimensions are clos
ely related to a family of Calabi-Yau l-folds. This allows us to reduce th
e computation of these integrals to the computation of the Calabi-Yau peri
ods. The periods are solutions of the Picard-Fuchs differential equations\
, which in turn are determined by the Yangian symmetry. Finally\, we show
that the values of these fishnet integrals admit a natural interpretation
as the quantum volume of the Calabi-Yau.\n
LOCATION:https://researchseminars.org/talk/AnLy/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jean-Luc Lehners (Postdam\, MPI)
DTSTART;VALUE=DATE-TIME:20221019T140000Z
DTEND;VALUE=DATE-TIME:20221019T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/15
DESCRIPTION:Title: Ho
w to create universes with internal flux\nby Jean-Luc Lehners (Postdam
\, MPI) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\n
String compactifications typically require fluxes\, for example in order t
o stabilise moduli. Such fluxes\, when they thread internal dimensions\, a
re topological in nature and take on quantised values. This poses the puzz
le as to how they could arise in the early universe\, as they cannot be tu
rned on incrementally. Working with string inspired models in 6 and 8 dime
nsions\, we show that there exist no-boundary solutions in which internal
fluxes are present from the creation of the universe onwards. The no-bound
ary proposal can thus explain the origin of fluxes in a Kaluza-Klein conte
xt. In fact\, it acts as a selection principle since no-boundary solutions
are only found to exist when the fluxes have the right magnitude to lead
to an effective potential that is positive and flat enough for accelerated
expansion. Within the range of selected fluxes\, the no-boundary wave fun
ction assigns higher probability to smaller values of flux. Our models ill
ustrate how cosmology can act as a filter on a landscape of possible highe
r-dimensional solutions.\n
LOCATION:https://researchseminars.org/talk/AnLy/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shai Chester (Weizmann Inst.)
DTSTART;VALUE=DATE-TIME:20221109T150000Z
DTEND;VALUE=DATE-TIME:20221109T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/16
DESCRIPTION:Title: Pu
re supergravity and the conformal bootstrap\nby Shai Chester (Weizmann
Inst.) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\n
We consider graviton scattering in maximal supergravity on Anti-de Sitter
space (AdS) in d+1 dimensions for d=3\, 4\, and 6 with no extra compact sp
acetime factor. Holography suggests that this theory is dual to an exotic
maximally supersymmetric conformal field theory (CFT) in d dimensions whos
e only light single trace operator is the stress tensor. This contrasts wi
th more standard cases like Type IIB string theory on AdS_5x S^5 dual to N
=4 Super-Yang-Mills\, where the CFT has light single trace operators for e
ach Kaluza-Klein mode on S^5. We compute the 1-loop correction to the pure
AdS_{d+1} theory in a small Planck length expansion\, which is dual to th
e large central charge expansion in the CFT. We find that this correction
saturates the most general non-perturbative conformal bootstrap bounds on
this correlator in the large central charge regime for d=3\, 4\, 6. After
imposing theory-specific constraints from localization in d=3\, 4\, the bo
otstrap constraints strengthen and are then saturated by the string/M-theo
ry dual CFT data.\n
LOCATION:https://researchseminars.org/talk/AnLy/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Bruno Valeixo Bento (U. Liverpool (main))
DTSTART;VALUE=DATE-TIME:20221123T150000Z
DTEND;VALUE=DATE-TIME:20221123T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/17
DESCRIPTION:Title: Gr
avity at the Tip of the Throat\nby Bruno Valeixo Bento (U. Liverpool (
main)) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\nW
arped throats have been used in countless works in the context of string t
heory compactifications\, in particular for their ability to suppress high
energy scales. I will focus on the gravitational sector of the resulting
4d EFT\, with its tower of Kaluza-Klein (KK) gravitons. By assuming that w
e live on a (3+1)-dimensional brane within the throat\, we can study how t
he warping influences the effects of this tower – in particular\, I will
show how the tower corrects the Newtonian potential and discuss how gravi
tational experiments and observations may be used to test the possibility
that our Universe corresponds to a brane living in a warped throat. I will
also briefly mention what this means for gravitational wave signatures o
riginating from different types of sources within this setup.\n
LOCATION:https://researchseminars.org/talk/AnLy/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Van Riet (Leuven U.)
DTSTART;VALUE=DATE-TIME:20221214T150000Z
DTEND;VALUE=DATE-TIME:20221214T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/18
DESCRIPTION:Title: A
supergravity view on a possible AdS1/CFT0 correspondence\nby Thomas Va
n Riet (Leuven U.) as part of AnLy Strings and Fields online seminars\n\n\
nAbstract\nTop down holography relies on a decoupling limit of closed and
open strings near the horizon of a stack of D branes. The simplest such ho
rizon geometries are of the form of an AdS space times a sphere times a to
rus with the total product space being a 10 or 11-dimensional solution of
supergravity. I will explain that this picture naturally leads one to cons
ider an extreme case which would be AdS1 x S1 x T9 and it would originate
from a brane bound state given by the so-called D7 -D instanton system\, w
hich is not fully understood in supergravity. I will point out that the du
al matrix model seems already written down in the literature before and it
is an extension of the IKKT matrix model. I will attempt to be pedagogica
l and the talk will mostly reflect the supergravity side of the problem.\n
LOCATION:https://researchseminars.org/talk/AnLy/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eduardo Gonzalo-Badia (Lehigh U.)
DTSTART;VALUE=DATE-TIME:20230111T150000Z
DTEND;VALUE=DATE-TIME:20230111T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/19
DESCRIPTION:Title: Ty
pe IIB flux compactifications with h^{1\,1} = 0\nby Eduardo Gonzalo-Ba
dia (Lehigh U.) as part of AnLy Strings and Fields online seminars\n\n\nAb
stract\nType IIB flux vacua based on Landau-Ginzburg models without Kähle
r deformations provide fully-controlled insights into the non-geometric an
d strongly-coupled string landscape. We show here that supersymmetric flux
configurations at the Fermat point of the 1^9 model\, which were found lo
ng-time ago to saturate the orientifold tadpole\, leave a number of massle
ss fields\, which however are not all flat directions of the superpotentia
l at higher order. More generally\, the rank of the Hessian of the superpo
tential is compatible with a suitably formulated tadpole conjecture for al
l fluxes that we found. Moreover\, we describe new infinite families of su
persymmetric 4d N = 1 Minkowski and AdS vacua and confront them with sever
al other swampland conjectures.\n
LOCATION:https://researchseminars.org/talk/AnLy/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Junho Hong (KU Leuven)
DTSTART;VALUE=DATE-TIME:20230125T150000Z
DTEND;VALUE=DATE-TIME:20230125T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/20
DESCRIPTION:Title: La
rge N partition functions\, holography\, and black holes\nby Junho Hon
g (KU Leuven) as part of AnLy Strings and Fields online seminars\n\n\nAbst
ract\nIn this talk\, I will present a simple closed form expression for th
e topologically twisted index of the ABJM theory as a function of the magn
etic fluxes and complexified electric chemical potentials valid at fixed k
and to all orders in the large N expansion. These results have important
implications for holography and the microscopic entropy counting of supers
ymmetric static AdS4 black holes. I will also discuss the squashed sphere
partition function and the superconformal index of the ABJM theory in a si
milar context. Finally\, I will briefly comment on the generalization to o
ther N = 2 superconformal field theories.\n
LOCATION:https://researchseminars.org/talk/AnLy/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:T. Grimm (Utrecht U.)
DTSTART;VALUE=DATE-TIME:20230222T150000Z
DTEND;VALUE=DATE-TIME:20230222T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/21
DESCRIPTION:Title: Th
e Tameness of Quantum Field Theory\nby T. Grimm (Utrecht U.) as part o
f AnLy Strings and Fields online seminars\n\n\nAbstract\nIn this talk I wi
ll introduce a generalized notion of finiteness and argue that it appears
in quantum field theories and in all well-understood string theory effecti
ve theories. The underlying mathematical foundation is described by the ta
me geometry that is built from o-minimal structures introduced in mathemat
ical logic. For renormalizable quantum field theories\, I will give a gene
ral proof that amplitudes at each order in the loop expansion are tame fun
ctions. I will discuss several exact non-perturbative results and show tha
t they are tame but only given constraints on the UV definition of the the
ory. I will present new evidence that tameness is linked to a consistent c
oupling to quantum gravity. Motivated by these insights\, I will suggest t
hat sets of consistent physical theories and their observables can be used
to define tame structures. I will make concrete conjectures how this is i
mplemented for conformal field theories and comment on some of the implica
tions.\n
LOCATION:https://researchseminars.org/talk/AnLy/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yixuan Li (Munich\, Max Planck Inst.)
DTSTART;VALUE=DATE-TIME:20230308T150000Z
DTEND;VALUE=DATE-TIME:20230308T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/22
DESCRIPTION:Title: Lo
cal supersymmetry enhancement and the entropy of three-charge black holes<
/a>\nby Yixuan Li (Munich\, Max Planck Inst.) as part of AnLy Strings and
Fields online seminars\n\n\nAbstract\nIn string theory\, black holes can b
e realised as bound states of branes and strings. The branes and the strin
gs preserve a set of global supersymmetries\, which imposes the geometry o
f the near-horizon region. However\, there exists a whole moduli space of
brane systems that preserve those same global supersymmetries\, but whose
number of local supersymmetries is enhanced. Such brane configuration shou
ld describe some microstates of the black hole\; but how much of the black
-hole entropy can these configurations account for? \n\nIn this talk\, I w
ill first present this formalism based on local supersymmetries that ident
ifies the ingredients needed to describe the microstates of a supersymmetr
ic black hole.\nThen\, I will illustrate the local supersymmetry enhanceme
nt mechanism with the three-charge F1-NS5-P black hole in Type IIA. The bl
ack-hole entropy is accounted by the fractionation\, due to the presence o
f the five-branes\, of the fundamental strings into many ‘little strings
’ which act as independent momentum carriers.\nI will apply the supersym
metric enhancement mechanism to these brane systems\, and show it gives ri
se to a new class of black-hole microstate solutions which preserve the ro
tational symmetry of the black-hole horizon. Finally\, I will explain why
one could expect their supergravity description to be horizonless in the M
-theory frame\, and how our results point towards a change of strategy in
the fuzzball programme in the endeavour of constructing horizonless black-
hole microstates.\n
LOCATION:https://researchseminars.org/talk/AnLy/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Ciambelli (Perimeter Institute)
DTSTART;VALUE=DATE-TIME:20230322T150000Z
DTEND;VALUE=DATE-TIME:20230322T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/23
DESCRIPTION:Title: Co
rner Symmetries in Gravity\nby Luca Ciambelli (Perimeter Institute) as
part of AnLy Strings and Fields online seminars\n\n\nAbstract\nIn the las
t 7 years\, we have gathered a lot of results pointing toward an underlyin
g universal symmetry structure in gravity. I will give an overview of thes
e recent results\, focussing in particular on two main features. First\, w
e will derive the universal corner symmetry algebra\, which can be regarde
d as the algebra of observables in classical gravity. Secondly\, we will p
ropose an extension of the gravitational covariant phase space such that a
ll diffeomorphism charges are integrable\, albeit the system is still diss
ipative. These two ingredients are at the core of the corner proposal\, wh
ich is a bottom-up approach to quantum gravity\, based on symmetries. Afte
r enunciating and discussing this proposal\, time permitting\, I will ment
ion how the geometric degrees of freedom at cuts of null hypersurfaces can
be quantized\, and its far-reaching consequences for quantum gravity.\n
LOCATION:https://researchseminars.org/talk/AnLy/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Sebastian Mizera (Princeton\, Inst. Advanced Study)
DTSTART;VALUE=DATE-TIME:20230405T140000Z
DTEND;VALUE=DATE-TIME:20230405T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/24
DESCRIPTION:Title: Ev
aluating one-loop string amplitudes\nby Sebastian Mizera (Princeton\,
Inst. Advanced Study) as part of AnLy Strings and Fields online seminars\n
\n\nAbstract\nScattering amplitudes in string theory are written as formal
integrals of correlations functions over the moduli space of punctured Ri
emann surfaces. It's well-known\, albeit not often emphasized\, that this
prescription is only approximately correct because of the ambiguities in d
efining the integration domain. In this talk\, we propose a resolution of
this problem for one-loop open-string amplitudes and present their first e
valuation at finite energy and scattering angle. Our method involves a def
ormation of the integration contour over the modular parameter to a fracta
l contour introduced by Rademacher in the context of analytic number theor
y. This procedure leads to explicit and practical formulas for the one-loo
p planar and non-planar type-I superstring four-point amplitudes\, amenabl
e to numerical evaluation. We plot the amplitudes as a function of the Man
delstam invariants and directly verify long-standing conjectures about the
ir behavior at high energies.\n
LOCATION:https://researchseminars.org/talk/AnLy/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Max Wiesner (Harvard U.\, CMSA)
DTSTART;VALUE=DATE-TIME:20230503T140000Z
DTEND;VALUE=DATE-TIME:20230503T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/25
DESCRIPTION:Title: Bo
unds on Species Scale and the Distance Conjecture\nby Max Wiesner (Har
vard U.\, CMSA) as part of AnLy Strings and Fields online seminars\n\n\nAb
stract\nThe species scale serves as a UV cutoff in the gravitational secto
r of an EFT and can depend on the moduli of the theory as the spectrum of
the theory varies. We argue that the slope of the species scale as a funct
ion of massless (or light) modes is bounded by an O(1) coefficient. This b
ound is true at all points in moduli space including also its interior. Th
e argument is based on the idea that the short distance contribution of ma
ssless modes to gravitational terms in the EFT cannot dramatically affect
the black hole entropy. Based on string theory arguments we expect the O(1
) constant in this bound to be equal to 1/d-2 as we approach the boundary
of the moduli space. However\, we find that the slope of the species scale
can approach its asymptotic value from above as we go from interior point
s to the boundaries\, thereby implying that the constant in the bound must
be larger than 1/d-2. The bound on the variation of the species scale als
o implies that the mass of towers of light modes cannot go to zero faster
than exponential in field distance in accordance with the Distance Conject
ure.\n
LOCATION:https://researchseminars.org/talk/AnLy/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lorenz Eberhardt (IAS\, Princeton)
DTSTART;VALUE=DATE-TIME:20230531T140000Z
DTEND;VALUE=DATE-TIME:20230531T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/26
DESCRIPTION:Title: So
lving 3d Gravity with Virasoro TQFT\nby Lorenz Eberhardt (IAS\, Prince
ton) as part of AnLy Strings and Fields online seminars\n\n\nAbstract\nI w
ill explain a proposal which relates three-dimensional quantum gravity in
AdS3 to a particular 3d TQFT that we refer to as ``Virasoro TQFT''. This r
elation gives a precise meaning to the standard folklore that pure 3d grav
ity is related to two copies of SL(2\,R) Chern-Simons theory. I will discu
ss that replacing SL(2\,R) Chern-Simons theory by Virasoro TQFT solves sev
eral known problems in the correspondence. The relation provides a computa
tionally useful tool to study partition functions of 3d gravity. The talk
is based o\n
LOCATION:https://researchseminars.org/talk/AnLy/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gerben Venken (University of Heidelberg\, ITP)
DTSTART;VALUE=DATE-TIME:20230517T140000Z
DTEND;VALUE=DATE-TIME:20230517T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/27
DESCRIPTION:Title: Th
e impact of alpha' corrections on de Sitter uplifts and warped throats
\nby Gerben Venken (University of Heidelberg\, ITP) as part of AnLy String
s and Fields online seminars\n\n\nAbstract\nOne of the most often-used pro
posals for constructing a de Sitter vacuum in string theory is by upliftin
g using a puffed-up anti-D3 brane in a warped throat as done in KKLT and L
VS. In recent years there has been much discussion about the validity and
control of such constructions\; more broadly\, the question of whether one
can obtain controlled de Sitter vacua at all in string theory has come un
der close scrutiny. In this talk I will consider puffed-up antibranes in a
warped throat and discuss the impact of alpha' corrections to the puffed
-up brane worldvolume theory on the dynamics of the brane (specifically th
e KPV process)\, what control one has over such corrections and whether su
ch correction pose an obstruction to a de Sitter uplift or are actually a
blessing in disguise. Based on arXiv:2212.07437.\n
LOCATION:https://researchseminars.org/talk/AnLy/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Manki Kim (MIT\, Cambridge\, CTP)
DTSTART;VALUE=DATE-TIME:20230628T140000Z
DTEND;VALUE=DATE-TIME:20230628T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/28
DESCRIPTION:Title: To
wards string loop corrections in Calabi-Yau orientifold compactifications<
/a>\nby Manki Kim (MIT\, Cambridge\, CTP) as part of AnLy Strings and Fiel
ds online seminars\n\n\nAbstract\nComputation of string loop corrections t
o the effective action has been one of the main challenges in string pheno
menology. One major complication for such computations is that the string
loop corrections are sensitive to the spectrum of strings probing Calabi-Y
au orientifolds\, which is practically inaccessible. In this talk\, I will
claim that some terms in the string one loop corrections to the Kahler po
tential are computed by more computable crude details of the string spectr
um. This result may pave a way to explicit computations of the string loop
corrections in generic Calabi-Yau orientifold compactifications.\n
LOCATION:https://researchseminars.org/talk/AnLy/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jerome Quintin (U. Waterloo\, Perimeter Inst.)
DTSTART;VALUE=DATE-TIME:20231004T140000Z
DTEND;VALUE=DATE-TIME:20231004T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/29
DESCRIPTION:Title: Ap
plications of the Kontsevich-Segal Bound in Quantum Cosmology\nby Jero
me Quintin (U. Waterloo\, Perimeter Inst.) as part of AnLy Strings and Fie
lds online seminars\n\n\nAbstract\nKontsevich and Segal have proposed a co
nstraint on complex metrics by demanding the path integral of p-form field
s to converge on a given fixed background. Witten has conjectured that thi
s constraint could apply to quantum gravity path integrals. The consequenc
es for quantum cosmology have thus been explored in the last couple of yea
rs. I will review some of these recent developments\, including classical
and quantum (tunnelling) transitions of the universe. Emphasis will be giv
en on the Hartle-Hawking no-boundary proposal\, where it is found that fla
tter potentials more easily satisfy the Kontsevich-Segal bound. When takin
g into account the weighting of the wave function\, which favours nucleati
on at low values on the inflationary potential\, the effects conspire to s
uggest that only a minimal amount of inflation could have occurred. This\,
in turn\, points towards our universe today being relatively small.\n
LOCATION:https://researchseminars.org/talk/AnLy/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Victor Rodriguez (Princeton U.)
DTSTART;VALUE=DATE-TIME:20231018T140000Z
DTEND;VALUE=DATE-TIME:20231018T150000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/30
DESCRIPTION:Title: Th
e Virasoro minimal string and 2d string cosmology\nby Victor Rodriguez
(Princeton U.) as part of AnLy Strings and Fields online seminars\n\n\nAb
stract\nI will introduce a new critical string theory in two dimensions an
d explain that this theory\, viewed as two-dimensional quantum gravity on
the worldsheet\, is equivalent to a double-scaled matrix integral. The wor
ldsheet theory consists of Liouville CFT coupled to timelike Liouville CFT
. The double-scaled matrix integral has as its leading density of states t
he universal Cardy density of primaries in a two-dimensional CFT of centra
l charge c\, thus motivating the name Virasoro minimal string. The duality
holds for any value of the continuous parameter c and reduces to the JT g
ravity/matrix integral duality in the large central charge limit\, providi
ng a precise stringy realization of JT gravity. From a target spacetime po
int of view\, I will describe how this theory may be viewed as a cosmologi
cal background in two dimensions.\n
LOCATION:https://researchseminars.org/talk/AnLy/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea Campoleoni (U. Mons)
DTSTART;VALUE=DATE-TIME:20231108T150000Z
DTEND;VALUE=DATE-TIME:20231108T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/31
DESCRIPTION:Title: Fl
at from anti-de Sitter\nby Andrea Campoleoni (U. Mons) as part of AnLy
Strings and Fields online seminars\n\n\nAbstract\nThe space of solutions
of Einstein's equations is severely altered by the presence of a cosmologi
cal constant. This is manifest when solving the equations of motion close
to the boundary of spacetime. In AdS all information about the solutions i
n encoded a metric and an energy-momentum tensor defined on the time-like
boundary. On the other hand\, at null infinity the information about the s
olutions is encoded in an infinite number of functions\, satisfying suitab
le flux-balance laws. In spite of these striking differences\, we show how
the space of Ricci-flat manifolds can be recovered from that of Einstein
spaces by expanding the AdS boundary energy-momentum in powers of the cosm
ological constant. In this process\, the flux-balance laws are also recove
red by demanding that the line element remains finite in the limit of vani
shing cosmological constant. The analysis is performed in a modified versi
on of the Newman-Unti gauge\, that has the additional advantage of natural
ly disclosing the Carrollian structures emerging at null infinity.\n
LOCATION:https://researchseminars.org/talk/AnLy/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matthew Kleban (New York U.\, CCPP)
DTSTART;VALUE=DATE-TIME:20231122T150000Z
DTEND;VALUE=DATE-TIME:20231122T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/32
DESCRIPTION:Title: Ax
ion Landscapes in Cosmology and String Theory\nby Matthew Kleban (New
York U.\, CCPP) as part of AnLy Strings and Fields online seminars\n\n\nAb
stract\nI will review axion landscapes in cosmology and explain their pote
ntial for explaining many of the large-scale features of our universe\, in
cluding the big bang\, inflation\, dark matter\, and dark energy. These e
xplanations can be successful when there are O(100s) of axion fields with
random scales and a random charge matrix that is not too sparse. Turning
to string theory\, I will describe recent work which numerically sampled t
he landscape of axions potentials in Calabi-Yau compactifications of type
IIB. While many of these compactifications admit hundreds of axions\, cor
relations between the scales and charges result in a meager landscape with
few unique minima in any given compactification. These results indicate
that explaining these features of our universe may require a more general
landscape with varying topology or flux.\n
LOCATION:https://researchseminars.org/talk/AnLy/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nat Levine (ENS\, Paris\, IPM)
DTSTART;VALUE=DATE-TIME:20231129T150000Z
DTEND;VALUE=DATE-TIME:20231129T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/33
DESCRIPTION:Title: Eq
uivalence of 1-loop RG flows in 4d Chern-Simons and integrable 2d sigma-mo
dels\nby Nat Levine (ENS\, Paris\, IPM) as part of AnLy Strings and Fi
elds online seminars\n\n\nAbstract\nCostello\, Witten and Yamazaki propose
d a 4d Chern-Simons theory as a unified way to engineer integrable models.
In the presence of 'Disorder' defects (for non-ultralocal 2d theories)\,
this correspondence has been established only classically. As a first quan
tum check\, I will derive the matching of 1-loop divergences between the 4
d and 2d theories. This study will uncover a simple\, 'universal' structur
e for the divergences in the 2d theory. My assumptions are general and see
m to isolate sigma-models among the 2d theories. (Based on 2309.16753)\n
LOCATION:https://researchseminars.org/talk/AnLy/33/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gianluca Inverso (INFN\, Padua)
DTSTART;VALUE=DATE-TIME:20231213T150000Z
DTEND;VALUE=DATE-TIME:20231213T160000Z
DTSTAMP;VALUE=DATE-TIME:20231210T223413Z
UID:AnLy/34
DESCRIPTION:Title: 2d
gauged maximal supergravities and Kaluza–Klein reductions\nby Gianl
uca Inverso (INFN\, Padua) as part of AnLy Strings and Fields online semin
ars\n\nInteractive livestream: https://cnrs.zoom.us/j/97090508975?pwd=NU85
dkJ0RGFPWjhuOVZGMEVRdkovQT09\n\nAbstract\nI will summarise the general fra
mework of consistent Kaluza–Klein truncations from D=11 and type II supe
rgravities to gauged maximal supergravities in two dimensions. This makes
it possible to describe the complete bosonic dynamics of all D=2 gauged ma
ximal supergravities that admit a geometric uplift.\nThe construction can
be applied in particular to prove and construct the consistent truncation
of eleven-dimensional supergravity on S8×S1 to D=2 SO(9) gauged supergrav
ity\, relevant for the holographic description of the M-theory/BFSS matrix
model.\n
LOCATION:https://researchseminars.org/talk/AnLy/34/
URL:https://cnrs.zoom.us/j/97090508975?pwd=NU85dkJ0RGFPWjhuOVZGMEVRdkovQT0
9
END:VEVENT
END:VCALENDAR