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BEGIN:VEVENT
SUMMARY:Protected states in AdS3xS3xT4 from integrability
DTSTART;VALUE=DATE-TIME:20201215T153000Z
DTEND;VALUE=DATE-TIME:20201215T160000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5045@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Suvajit Majumder (City\, University of London)\nI wi
ll briefly review the integrability setup that works in AdS3/CFT2\, in the
planar limit\, including its brane construction in type IIB string theory
. Next\, I will review algebraic Bethe ansatz(ABA) and how it is used to c
ompute spectrum of integrable models by working with the concrete example
of Heisenberg XXX spin chain. Finally\, I will use the ABA technology for
the massless modes in AdS3xS3xT4\, and use it to compute the protected spe
ctrum of states in this background.\n\nhttps://conference.ippp.dur.ac.uk/e
vent/937/contributions/5045/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5045/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analytical Approximations for Curved Primordial Power Spectra
DTSTART;VALUE=DATE-TIME:20201215T160000Z
DTEND;VALUE=DATE-TIME:20201215T163000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5024@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Ayngaran Thavanesan (University of Cambridge)\nWhils
t interpretations of the level of experimental support for a curved presen
t-day universe differ\, universe models with percent-level spatial curvatu
re remain compatible with CMB datasets. The inflationary framework success
fully predicts the minimal present-day curvature. However\, if one is to s
tudy inflation in a complete manner\, one cannot assume a flat universe at
the start of the expansion. There are also other theoretical reasons to c
onsider the effect of curvature\; particularly for the studies of inflatio
n exits and quantum gravity.\n\nThis motivates us to study the effects of
primordial curvature. In this work\, we generalize the potential-independe
nt inflationary model\, popularized by Contaldi et al.\, to the curved cas
e. We demonstrate that the Contaldi approximation still holds for the case
of curved universes\, and allows us to clearly illustrate the generic cut
-off and oscillatory effects seen in numerically computed curved primordia
l power spectra. Through our analytical solutions\, we are able to gain a
better insight into the physics of curved inflating universes. We also dis
cuss the possibility of developing our framework to include potential depe
ndence.\n\nhttps://arxiv.org/abs/2009.05573\n\nhttps://conference.ippp.dur
.ac.uk/event/937/contributions/5024/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5024/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Never have I ever used a constant to fix my problem
DTSTART;VALUE=DATE-TIME:20201216T123000Z
DTEND;VALUE=DATE-TIME:20201216T130000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5037@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Bruno Bento (University of Liverpool)\nWas it callin
g it a blunder the actual blunder? The cosmological constant has always be
en controversial\, to say the least. The past 20 years have seen an uprisi
ng of the cosmological constant\, after the discovery in 1998 that the exp
ansion of the universe is actually accelerating. This forced String Theory
to try to accommodate de Sitter backgrounds into its 4d solutions\, somet
hing that has proved difficult to accomplish. However\, just as Inflation
seems to be best dealt with using slowly rolling scalar fields rather than
a de Sitter vacuum\, so may the current expansion be driven by such field
s\, in what is known as Quintessence. In this talk I will address the prob
lem with the cosmological constant\, explain how Quintessence can provide
an alternative\, notwithstanding its own difficulties\, and how this can b
e accomplished in String Theory.\n\nhttps://conference.ippp.dur.ac.uk/even
t/937/contributions/5037/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5037/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Non-SUSY String Phenomenology from Z$_2\\times$Z$_2$ Heterotic Orb
ifolds
DTSTART;VALUE=DATE-TIME:20201216T120000Z
DTEND;VALUE=DATE-TIME:20201216T123000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5015@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Benjamin Percival (Liverpool University)\nWe explore
the space of non-SUSY string models via two distinct routes: the tachyon-
free O(16)$\\times$O(16) heterotic string in 10D and a tachyonic 10D heter
otic string. We classify 4D Z$_2\\times$Z$_2$ orbifolds descending from th
ese two starting points in the free fermionic construction. Having found a
potentially stable Standard-like model descending from the tachyonic 10D
vacuum in [arXiv:1912.00061](https://arxiv.org/abs/1912.00061)\, the appro
ach of taking these models on equal footing with the non-tachyonic 10D mod
els is justified provided that the tachyonic states are projected out in t
he four dimensional models. In both classes of models we find examples of
Type 0 and Type 0bar models\, i.e. models free of fermionic massless state
s and models free of twisted massless bosons\, respectively. Moving beyond
these extreme configurations we seek to classify tachyon-free vacua accor
ding to standard phenomenological criteria in both classes of model\, wher
e an SO(10) GUT is broken to the Pati-Salam subgroup. An analysis of the c
osmological constant and misaligned supersymmetry in the two classes of mo
dels finds notable vacua in both cases in which N$_b$=N$_f$ at the massles
s level.\n\nhttps://conference.ippp.dur.ac.uk/event/937/contributions/5015
/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5015/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Covariant multipole expansion of local currents for massive states
of any spin
DTSTART;VALUE=DATE-TIME:20201216T160000Z
DTEND;VALUE=DATE-TIME:20201216T163000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5025@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Manuel Morales (DAMTP\, University of Cambridge)\nWe
study the structure of scalar\, vector\, and tensor currents for on-shell
massive particles of any spin. When considering higher values for the spi
n of the particle\, the number of form factors (FFs) involved in the decom
position of the matrix elements associated with these local currents incre
ases. We identify all the fundamental structures that give rise to the ind
ependent FFs\, systematically for any spin value. These structures can be
conveniently organised using an expansion in covariant multipoles\, built
solely from the Lorentz generators. This approach allows one to uniquely i
dentify the terms which are universal and those that arise because of spin
. We derive counting rules which relate the number of FFs to the total spi
n j of the state\, showing explicitly that these rules match all the well-
known cases up to spin 2.\n\nhttps://conference.ippp.dur.ac.uk/event/937/c
ontributions/5025/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5025/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Double copy and homotopy algebras
DTSTART;VALUE=DATE-TIME:20201216T153000Z
DTEND;VALUE=DATE-TIME:20201216T160000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5020@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Hyungrok Kim (Heriot-Watt University)\nThere is a se
ries of deep relations between the scattering amplitudes of Yang–Mills t
heory and those of Einstein gravity\, known as *double copy*. This relatio
n has been proven at tree level\, but whether it holds at loop level has b
een a longstanding conjecture. In this talk we resolve this by constructin
g Lagrangians for Yang–Mills theory and Einstein gravity that manifest t
he double copy relation and formulate the result in terms of the theory of
homotopy algebras (L∞-\, A∞-algebras).\n\nBased on [2007.13803][1]\,
joint work with L. Borsten\, B. Jurčo\, T. Macrelli\, C. Sämann\, M. Wol
f.\n\n [1]: https://arxiv.org/abs/2007.13803\n\nhttps://conference.ippp.d
ur.ac.uk/event/937/contributions/5020/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5020/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Boundaries\, Vermas\, and Factorisation
DTSTART;VALUE=DATE-TIME:20201216T143000Z
DTEND;VALUE=DATE-TIME:20201216T150000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5005@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Daniel Zhang (University of Cambridge)\nI will discu
ss a recent work on the factorisation of closed 3-manifold partition funct
ions and indices of 3d $\\mathcal{N}=4$ gauge theories. The building block
s are hemisphere partition functions equipped with a class of UV $\\mathca
l{N}=(2\,2)$ boundary conditions that mimic the presence of isolated vacua
at infinity. Via the state-operator correspondence\, these count local op
erators supported on a $(2\,2)$ boundary condition on a plane. A subset of
these operators are boundary Higgs and Coulomb branch operators\, which f
orm lowest weight Verma modules over the quantised bulk Higgs and Coulomb
branch chiral rings. We show that certain limits of the hemisphere partiti
on functions compute their characters. We find that the equivariant supers
ymmetric Casimir energy encodes the boundary ’t Hooft anomaly\, and also
plays the role of highest weights. Applying these results to factorisatio
n then leads to various “IR formulae” for partition functions on close
d 3-manifolds in terms of these Verma characters.\n\nhttps://conference.ip
pp.dur.ac.uk/event/937/contributions/5005/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5005/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Avoided Deconfinement in Randall-Sundrum Models
DTSTART;VALUE=DATE-TIME:20201216T140000Z
DTEND;VALUE=DATE-TIME:20201216T143000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5051@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Michael Nee (Oxford University)\nIn this talk I will
discuss first order phase transitions in Randall-Sundrum models which are
dual to (de)confinement phase transitions in large-$N$ gauge theories. Th
e transition rate is suppressed by a factor $\\exp(-N^2)$\, and does not c
omplete for $N \\gg 1$\, leading to an eternally inflating phase. The cons
traint on $N$ to avoid this fate is strong enough that the RS effective fi
eld theory is only marginally under control. We present a mechanism where
the IR brane remains stabilised at very high temperature\, so that the the
ory stays in the confined phase at arbitrarily high energies. This mechani
sm of avoided deconfinement is similar to Weinberg's symmetry non-restorat
ion mechanism. Avoided deconfinement allows for a viable cosmology for pa
rametrically large-$N$ theories. Early universe phenomena such as WIMP fre
eze-out\, axion abundance\, baryogenesis and phase transitions are qualita
tively modified in the model\, leading to new possibilities for phenomenol
ogical applications.\n\nhttps://conference.ippp.dur.ac.uk/event/937/contri
butions/5051/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5051/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Classical Yang Mills observables from amplitudes
DTSTART;VALUE=DATE-TIME:20201216T110000Z
DTEND;VALUE=DATE-TIME:20201216T113000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5027@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Alasdair Ross (University of Edinburgh)\nIn this tal
k I’ll present some recent work on studying classical observables in Yan
g Mills theory. Motivated by the double copy relation between YM and Gravi
ty\, and focusing on the YM side\, I’ll discuss the classical scattering
of particles with a YM colour charge and compute the change in colour or
‘colour impulse’ that occurs during the scattering event using amplitu
des techniques.\n\nhttps://conference.ippp.dur.ac.uk/event/937/contributio
ns/5027/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5027/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Amplitudes and Backgrounds in Split Signature
DTSTART;VALUE=DATE-TIME:20201216T103000Z
DTEND;VALUE=DATE-TIME:20201216T110000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5048@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Matteo Sergola (University of Edinburgh)\nIn this ta
lk we are going to explore classical features of electromagnetic and gravi
tational radiation using quantum scattering amplitudes. To do so we analyt
ically continue to a spacetime with $(2\,2)$ signature $\\eta_{\\mu\\nu}=\
\text{diag}(+\,+\,-\,-)$. This allows us to consider\, at leading order\,
3-point on-shell amplitudes which would otherwise be identically zero in u
sual Minkowski spacetime. Our main result is that\, in the classical limit
\, the scattered state is a coherent state which is the exponential of a 3
-point amplitude. This occurs for both EM and GR radiation\, which happen
to be related to each other through the double copy. This opens up new pos
sibilities to study gravitational wave physics with quantum field theory a
nd unitarity methods.\n\nhttps://conference.ippp.dur.ac.uk/event/937/contr
ibutions/5048/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5048/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Curvy Parke-Taylors
DTSTART;VALUE=DATE-TIME:20201216T100000Z
DTEND;VALUE=DATE-TIME:20201216T103000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5004@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Atul Sharma (University of Oxford)\nI will report on
our discovery of the first-ever all-multiplicity formulae for scattering
amplitudes in curved backgrounds. This will involve certain chiral backgro
unds treated without any approximations\, a slice of twistor theory\, a ta
ste of spinor-helicity variables\, and a bit of holography for dessert. Th
e end result is a beautiful extension of the Parke-Taylor formula of MHV g
luon amplitudes from trivial backgrounds to an infinite class of self-dual
radiative gauge field backgrounds.\n\nhttps://conference.ippp.dur.ac.uk/e
vent/937/contributions/5004/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5004/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Synthetic Flux Attachment
DTSTART;VALUE=DATE-TIME:20201215T140000Z
DTEND;VALUE=DATE-TIME:20201215T143000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5012@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Gerard Valentí-Rojas (Heriot-Watt University)\nFlux
attachment is a mechanism by which charged particles capture magnetic flu
x quanta and form composite entities. As a consequence of flux dressing\,
these composites may acquire fractional quantum numbers (e.g. electric cha
rge) and statistics. This phenomenon is directly associated to the emergen
ce of a Chern-Simons gauge field.\n\nAlthough charge-neutral systems do no
t couple to vector potentials\, geometric (Berry) phases induced in ultrac
old neutral atoms allow emulating the behaviour of charged particles in el
ectromagnetic fields. Nowadays\, these phases can be engineered in Bose-Ei
nstein condensates by means of laser coupling.\n\nWe describe how a suitab
le interaction of this light-matter system generates an effective singular
nonlinear gauge potential. Such a field is a function of matter density a
nd performs a laser-tuned version of flux attachment. We derive bottom-up
the macroscopics (i.e. emergence) of an Abelian Chern-Simons theory from a
microscopic\, weakly-interacting system of bosons. We find that the effec
tive description of the condensate is that of a fractional quantum Hall fl
uid where anyonic flux-charge vortices are formed. Finally\, we outline th
e implementation of the current scheme and its implications as a quantum s
imulation of a gauge theory in 2+1D that uses a single atomic species only
.\n\nhttps://conference.ippp.dur.ac.uk/event/937/contributions/5012/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5012/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Multi-winding Magnetic Fluxtubes in Colour-superconducting Quark M
atter
DTSTART;VALUE=DATE-TIME:20201215T143000Z
DTEND;VALUE=DATE-TIME:20201215T150000Z
DTSTAMP;VALUE=DATE-TIME:20211023T012815Z
UID:indico-contribution-1194-5047@conference.ippp.dur.ac.uk
DESCRIPTION:Speakers: Geraint Evans (University of Southampton)\nI will pr
esent results analysing the phase structure of dense\, three-flavour\, col
our-superconducting quark matter in the presence of an external magnetic f
ield using a Ginzburg-Landau approach. By contrasting with the massless ca
se\, I will discuss how the preferred magnetic defects in the type-II 2SC
phase and overall phase diagram are affected when we consider the strange
quark mass to be non-zero.\n\nhttps://conference.ippp.dur.ac.uk/event/937/
contributions/5047/
LOCATION:Centre for Particle Theory\, Durham Teams
URL:https://conference.ippp.dur.ac.uk/event/937/contributions/5047/
END:VEVENT
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