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X-WR-CALNAME:Particle Physics Theory Seminars
X-WR-CALDESC:Particle Physics Theory Seminars
X-PUBLISHED-TTL:PT12H
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:Europe/London
X-LIC-LOCATION:Europe/London
BEGIN:DAYLIGHT
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
DTSTART:19810329T010000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
TZNAME:BST
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
DTSTART:19961027T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
TZNAME:GMT
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83104@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230223T150935
LAST-MODIFIED:20230628T153638
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20230628T140000
DTEND;TZID=Europe/London:20230628T150000
SUMMARY:Solving Beautiful Puzzles
DESCRIPTION:Beauty meson decays are important in the search for physics be
yond the Standard Model (SM) of particle physics. The large amount of data
gathered by the B factories and LHCb allows testing the SM with an unprec
edented precision\, probing scales much higher than the reach of direct se
arches at the LHC. In this sense\, B mesons serve as a Telescope in the se
arch for new interactions and particles. To do so\, requires precise and r
eliable theoretical predictions. In this talk\, I will discuss some of the
puzzles in flavour physics\, and present the challenges and new ideas to
push the theoretical precision up. Specifically\, I will focus on the dete
rmination of the CKM element Vcb\, Vub.\n\nSpeaker:\n* Keri Vos (Maastrich
t University)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, JCMB
URL:https://www.ph.ed.ac.uk/events/2023/83104-solving-beautiful-puzzles
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83561@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T085520
LAST-MODIFIED:20230909T090117
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231004T140000
DTEND;TZID=Europe/London:20231004T150000
SUMMARY:Kerr Amplitudes from Higher Spin Theory
DESCRIPTION:Title:\n\nKerr Amplitudes from Higher Spin Theory\n \n\nAbst
ract:\n\nHigher-spin theory and massive gauge invariance can be used as in
put for constraining root-Kerr and Kerr amplitudes\, relevant for calculat
ing gravitational observables with spin. Elegant three-point spin-s amplit
udes exist for Kerr black holes\, however constructing the corresponding f
our-point Compton amplitudes is an open problem. In this talk\, I will dis
cuss the origin of the Kerr three-point amplitudes from a higher-spin theo
ry perspective. Guided by higher-spin constraints and classical-limit anal
ysis\, I will propose quantum and classical tree-level Compton amplitudes
relevant for root-Kerr and Kerr to all orders in spin.\n\nSpeaker:\n* Luci
le Cangemi (Uppsala University)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83561-kerr-amplitudes-from-higher-
spin-theory
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83562@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T085851
LAST-MODIFIED:20231005T115949
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231011T140000
DTEND;TZID=Europe/London:20231011T150000
SUMMARY:Muon-Electron scattering at 10ppm for MUonE
DESCRIPTION:Title: \n\nMuon-Electron scattering at 10ppm for MUonE\n\nAbs
tract:\n\nThe MUonE experiment aims at extracting the hadronic vacuum\n po
larisation through a precise measurement of muon-electron scattering.\n Th
is novel approach will shed light on the current disagreement between\n th
e traditional dispersive determination and lattice computations\,\n result
ing in different predictions for the muon g-2. However\, a\n competitive e
xtraction with MUonE requires a fully-differential\n calculation of muon-e
lectron scattering at the level of 10ppm. I will\n present our efforts in
the McMule team to achieve this level of\n precision. An emphasis will be
put on the methods that we have\n developed for this type of calculation:
the infrared subtraction\n scheme\, massification\, and next-to-soft stabi
lisation. After presenting\n our current results\, I will talk about the p
ossibility of going beyond\n NNLO.\n\nSpeaker:\n* Tim Engel (Universität
Freiburg)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83562-muon-electron-scattering-at-
10ppm-for-muone
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83566@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T091525
LAST-MODIFIED:20230909T091812
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231018T140000
DTEND;TZID=Europe/London:20231018T150000
SUMMARY:Is dark matter fact or fantasy? -- clues from the data
DESCRIPTION:Title:\n\nIs dark matter fact or fantasy? -- clues from the da
ta\n\nAbstract:\n\nWe discuss the arguments both in favor of and against d
ark matter. With the repeated failure of experiment to detect dark matter
we discuss what could be done instead\, and to this end look for clues in
the data themselves. We identify a contribution to galactic rotation curv
es coming from the rest of the visible Universe\, and suggest that dark ma
tter is just an attempt to describe this global effect in terms of standar
d Newtonian gravity within galaxies. Thus the missing or dark mass is not
missing at all -- it has been hiding in plain sight all there along as
the rest of the visible mass in the Universe.\n\nSpeaker:\n* Philip Mannhe
im (University of Connecticut)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83566-is-dark-matter-fact-or-fanta
sy-clues-from-the-data
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83568@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T091749
LAST-MODIFIED:20231018T093243
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231025T140000
DTEND;TZID=Europe/London:20231025T150000
SUMMARY:Hide and seek: how PDFs can conceal new physics
DESCRIPTION:Title:\n\nHide and seek: how PDFs can conceal new physics\n\n
Abstract:\n\nThe Standard Model Effective Field Theory (SMEFT) provides a
powerful theoretical framework for interpreting subtle deviations from t
he Standard Model and searching for heavy new physics at the LHC. Accu
rate interpretations of LHC data\, however\, rely on the precise knowledg
e of the proton structure in terms of parton distribution functions (PDFs
). In this seminar\, I will discuss the interplay between PDFs and th
e search for new physics. I will showcase a scenario for the High-Lumi
nosity LHC in which the PDFs may completely absorb such signs of new phys
ics\, thus biasing theoretical predictions and interpretations. To addr
ess this challenge\, I will present a simultaneous determination of PDFs
and the SMEFT using the SIMUnet methodology. This approach integrates
both PDF and SMEFT determinations into a single\, coherent framework\, m
aking possible an assessment of the regions of parameter space in which t
he interplay is most phenomenologically relevant\, both at the LHC and HL
-LHC.\n \n\nSpeaker:\n* Maeve Madigan (Universität Heidelberg)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83568-hide-and-seek-how-pdfs-can-c
onceal-new-physics
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83570@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T091927
LAST-MODIFIED:20231017T145003
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231101T140000
DTEND;TZID=Europe/London:20231101T150000
SUMMARY:Magnetic susceptibility of QCD matter
DESCRIPTION:Title:\n\nMagnetic susceptibility of QCD matter\n\n\n\nAbstrac
t:\n\nIn the cores of magnetars\, during neutron star mergers and in heavy
\n ion collisions magnetic fields can be found that are so strong that\n t
he properties of strongly interacting matter may be affected\,\n possibly
with observable consequences. Theoretical expectation\n relating to matter
in such environments will be presented. These have\n mostly been obtained
by numerical lattice QCD computations. QCD matter\n turns out to be diama
gnetic at low temperatures and paramagnetic at\n high temperatures. The ma
gnetic susceptibility can be further\n decomposed into a Pauli spin contri
bution and angular momentum related\n Landau contributions. The former is
related to the so-called\n normalization of the photon light cone distribu
tion amplitude.\n\nSpeaker:\n* Gunnar Bali (Universität Regensburg)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83570-magnetic-susceptibility-of-q
cd-matter
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83572@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T092222
LAST-MODIFIED:20231102T122604
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231108T140000
DTEND;TZID=Europe/London:20231108T150000
SUMMARY:The Classical Double Copy and Twistors
DESCRIPTION:Title:\n\nThe Classical Double Copy and Twistors \n\nAbstra
ct:\n\nThe last twenty years or so have given rise to an interesting relat
ionship (known as the double copy) at the level of scattering amplitudes b
etween non-abelian gauge theories (such as Yang-Mills theory) and quantum
gravity theories. After half a decade\, this duality was seen to be presen
t in classical physics for exact solutions in classical Yang-Mills theory
and general relativity. Ten years on\, the classical double copy has seen
tremendous attention and development. One such development is the applicat
ion of twistor theory to the classical double copy\; where we can express
spacetime fields as infinite complex “lines” in twistor space\, which
can be used to generate new double copies. This talk will describe how thi
s work has been extended to connect the momentum space double copy for sca
ttering amplitudes with the position space double copy for classical field
s\; as well as its application to find a novel classical double copy for N
=0 supergravity. This talk will be based on work done in arxiv:2303.04631.
\n\nSpeaker:\n* Kymani Armstrong-Williams (Queen Mary University of Lond
on)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83572-the-classical-double-copy-an
d-twistors
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83574@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T092522
LAST-MODIFIED:20231109T132416
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231115T130000
DTEND;TZID=Europe/London:20231115T150000
SUMMARY:Inclusive hadronic decay rate of the tau lepton from lattice QCD
DESCRIPTION:Title:\n\nInclusive hadronic decay rate of the tau lepton from
lattice QCD\n\nAbstract:\n\nThe inclusive hadronic decays of the $\\tau$
are of great interest\, as they provide an alternative way of determining
the CKM matrix elements\n $V_{\\rm ud}$ and $V_{\\rm us}$. However\, a dir
ect lattice QCD calculation of the corresponding inclusive hadronic decay
rates is hindered by the\n need of performing a numerical inverse Laplace
transform of an Euclidean correlation function\, a notoriously ill-posed p
roblem. In this seminar\, I will discuss a novel approach that effectively
bypasses the inverse Laplace transform problem\, and that allows to eva
luate the inclusive decay rates in given flavour channels without relying
on the operator-product expansion or perturbative QCD. The method is appli
ed to the inclusive decay $\\tau \\to X_{\\rm ud} \\nu_{\\tau}$\, where $X
_{\\rm ud}$ represents any hadronic state with $\\bar{u}d$ flavour quantum
numbers. With all sources of systematic errors under control\, except for
isospin-breaking effects\, we obtain a value for $|V_{ud}|$ with an accur
acy of $0.4\\%$\, which is in agreement with the determination from supera
llowed nuclear beta decays. Finally\, I will discuss the prospects for det
ermining $|V_{\\rm us}|$ from $\\tau \\to X_{\\rm us} \\nu_{\\tau}$.\n\nSp
eaker:\n* Giuseppe Gagliardi (Università Roma Tre)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83574-inclusive-hadronic-decay-rat
e-of-the-tau-lepton-from-lattice-qcd
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83576@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T092800
LAST-MODIFIED:20231117T132025
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231122T140000
DTEND;TZID=Europe/London:20231122T150000
SUMMARY:Proton structure in and out of muonic hydrogen
DESCRIPTION:Title:\n\nProton structure in and out of muonic hydrogen\n\nAb
stract:\n\nIn this talk\, I will start with a short review of proton radiu
s puzzle and its present status\, covering lepton-proton scattering\, as w
ell as hydrogen and muonic-hydrogen spectroscopy. After that\, I will dis
cuss the spectroscopy of light muonic atoms with a focus on nucleon- and
nuclear structure corrections from two-photon exchange. As an outlook\, I
will briefly touch on the potential of precision spectroscopy to test QED
and nuclear theories\, refine fundamental constants\, and search for New P
hysics. \n\nSpeaker:\n* Franziska Hagelstein (Johannes Gutenberg-Universi
tät Mainz)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83576-proton-structure-in-and-out-
of-muonic-hydrogen
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83734@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20231102T090359
LAST-MODIFIED:20231102T122651
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231123T133000
DTEND;TZID=Europe/London:20231123T143000
SUMMARY:Spacetime emergence in group field theory
DESCRIPTION:Title: \n\nSpacetime emergence in group field theory\n\nAbstr
act: \n\nThe failure of a simple perturbative quantisation of general rel
ativity\n suggests that quantum gravity is fundamentally non-perturbative\
, defined\n by a path integral or sum over spacetime histories. In some ap
proaches\n even the spacetime manifold and its topology are not fixed back
ground\n structures but part of the sum: we then have a quantum theory "of
\, not\n on spacetime". I will briefly review one such approach\, group fi
eld\n theory\, which can be seen as an extension of matrix and tensor mode
ls to\n higher dimensions. I will highlight a number of applications to\n
cosmology\, including the derivation of an effective Friedmann equation\n
(with higher-curvature corrections leading to a bounce) for homogeneous\n
cosmology\, and recent work showing how a spacetime metric can be\n extrac
ted from this formalism\, paving the way towards a physical\n interpretati
on of many other solutions of the theory.\n\nSpeaker:\n* Steffen Gielen (U
niversity of Sheffield)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83734-spacetime-emergence-in-group
-field-theory
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83578@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T093322
LAST-MODIFIED:20231115T162241
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231129T140000
DTEND;TZID=Europe/London:20231129T150000
SUMMARY:Perturbative renormalization by the flow equations of boundary fie
ld theory
DESCRIPTION:Title:\n\nPerturbative renormalization by the flow equations o
f boundary field theory\n\nAbstract:\n\nThe aim of this talk is to give an
overview of the rigorous proof of perturbative renormalization based on t
he Polchinski flow equation. First\, I will explain the general method for
the simple case of the massive scalar field theory with a quartic self-in
teraction in the full space $\\mathbb{R}^4$. Then\, I will explain the dif
ficulties one encounters for theories that break translation invariance\,
in particular by the presence of a surface. This problem will be adressed
by studying the renormalization problem of the scalar field model define
d on a half-space as an example of a Euclidean boundary field theory. I wi
ll present our main results in this direction based on uniform bounds with
respect to the UV cutoff of the correlators\, which compared to the trans
lationally invariant case\, require some weight factors that account for t
heir distributional structure when considered in position space.\n\nSpeake
r:\n* Majdouline Borji (Ecole Polytechnique)
LOCATION:Room 5326\, JCMB
URL:https://www.ph.ed.ac.uk/events/2023/83578-perturbative-renormalization
-by-the-flow-equations-of-boundary-field-theory
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83778@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20231117T083248
LAST-MODIFIED:20231129T133726
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231205T140000
DTEND;TZID=Europe/London:20231205T150000
SUMMARY:Chiral fermions in gravity: anomalies and path integral methods
DESCRIPTION:Title: Chiral fermions in gravity: anomalies and path integra
l methods\n\nAbstract: Dealing with chiral fermions in gravity can prove
a difficult task\, which is not easily handled with Feynman diagrams. The
path integral approach provides a powerful alternative\, both on the forma
l and practical aspects. Recent improvements allowed to deal with chiral f
ermions in gravity\, hence filling a gap in the literature. It then helped
solving a controversy that spanned over a decade\, concerning the presenc
e or absence of the CP-odd Pontryagin density in the trace anomaly of the
neutrino. In this talk\, we describe how the path integral can be properly
defined and used to compute quantum anomalies\, and more generally we out
line how it can be used to obtain a generic one-loop effective action for
chiral fermions.\n\nSpeaker:\n* Rémy Larue (Université Grenoble-Alpes)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83778-chiral-fermions-in-gravity-a
nomalies-and-path-integral-methods
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83580@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T093713
LAST-MODIFIED:20230909T124805
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231206T140000
DTEND;TZID=Europe/London:20231206T150000
SUMMARY:The Dilaton EFT\, the Lattice and the Composite Higgs
DESCRIPTION:Title:\n\nThe Dilaton EFT\, the Lattice and the Composite Higg
s\n\nAbstract:\n\nIn this talk\, I review recent work developing dilaton e
ffective field theory (EFT)\, which provides a framework for describing th
e Higgs boson as composite state. The EFT includes a multiplet of pseudo-G
oldstone bosons which arise when an approximate global symmetry gets spont
aneously broken\, as well as the dilaton - a pseudo-Goldstone boson arisin
g from the spontaneous breaking of an approximate conformal symmetry. The
interactions of these states are then powerfully constrained by symmetry p
rinciples and power counting rules. The EFT has been checked against resul
ts from lattice gauge theory and used to build novel composite Higgs model
s in which the real world Higgs is an admixture of both the dilaton and on
e state from the multiplet of pseudo-Goldstone bosons.\n\nSpeaker:\n* Jame
s Ingoldby (Durham University)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83580-the-dilaton-eft-the-lattice-
and-the-composite-higgs
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83582@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20230909T093829
LAST-MODIFIED:20231211T153900
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20231213T140000
DTEND;TZID=Europe/London:20231213T150000
SUMMARY:Charges and fluxes in cosmological backgrounds
DESCRIPTION:Title:\n\nCharges and fluxes in cosmological backgrounds\n\n\n
\nAbstract:\n\n\n\nFollowing the detection of gravitational waves by the
ground based LIGO detectors\, space based experiments are planned to det
ect gravitational waves at different frequencies\, both those associated w
ith supermassive black holes and those produced in the early Universe.
This talk will explore the definition of fluxes and charges in cosm
ological backgrounds\, which is relevant to the theoretical understanding
of gravitational waves in our Universe. We will begin by explaining the
subtleties in defining charges in general relativity\, and how thes
e are addressed by an approach developed by Wald and collaborators. We
will then extend this approach to de Sitter like cosmologies and expl
ain how charges/fluxes can be defined in this context\, illustrating
with some physical examples.\n\nSpeaker:\n* Marika Taylor (University of S
outhampton)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2023/83582-charges-and-fluxes-in-cosmol
ogical-backgrounds
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83890@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T111332
LAST-MODIFIED:20240130T173454
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240131T130000
DTEND;TZID=Europe/London:20240131T150000
SUMMARY:QCD with an Infrared Fixed Point and a Dilaton
DESCRIPTION:Title: \n\nQCD with an Infrared Fixed Point and a Dilaton\n\n
Abstract: \n\nThe possibility that QCD\, or a chirally broken phase of a
gauge theory\, admits an infrared fixed point interpretation is explored.
I will first review the conformal window and show that the assumptions l
ead to a consistent picture\, including N=1 supersymmetric gauge theories.
Scaling dimensions of the QCD-operators will be determined in various way
s by matching it to the pion sector. In a second part I will speculate on
a dilaton and discuss some properties from the soft theorem perspective.
At last\, an outlook is given on the sigma-meson as a dilaton in QCD and i
t is discussed what dilaton-properties would make it amenable to a Higgs b
oson interpretation.\n\nSpeaker:\n* Professor Roman Zwicky (School of Phys
ics & Astronomy\, University of Edinburgh)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83890-qcd-with-an-infrared-fixed-p
oint-and-a-dilaton
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83937@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240124T082659
LAST-MODIFIED:20240212T135615
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240214T130000
DTEND;TZID=Europe/London:20240214T150000
SUMMARY:QED radiative corrections in pion and kaon decays
DESCRIPTION:Title: \n\nQED radiative corrections in pion and kaon decays\
n\nAbstract: \n\nIn the context of the decays of the lightest hadrons (ma
inly the neutral pion and charged kaon)\, I will talk about the role of QE
D radiative corrections when measuring the branching ratios and form-facto
r parameters involved. Related tensions between theory and experiment will
be discussed.\n\nSpeaker:\n* Tomas Husek (University of Birmingham)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83937-qed-radiative-corrections-in
-pion-and-kaon-decays
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83892@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T111624
LAST-MODIFIED:20240216T141935
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240221T140000
DTEND;TZID=Europe/London:20240221T150000
SUMMARY:Gravitational Waves from Scattering Amplitudes
DESCRIPTION:Title: Gravitational Waves from Scattering Amplitudes\n\nAbst
ract: Recent years have seen significant advancements in employing tools
from Quantum Field Theory\, specifically Scattering Amplitudes\, to inform
theoretical predictions for gravitational waveforms generated by binary s
ystems. In this talk I will discuss how using these methods we have obtain
ed new results pertaining to the gravitational interaction of spinning obj
ects\, as well as seen hints of novel physical phenomena that will potenti
ally manifest in the gravitational waveform.\n\nSpeaker:\n* Dimitrios Kosm
opoulos (University of Geneva)
LOCATION:Room 5326\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/83892-gravitational-waves-from-sca
ttering-amplitudes
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83894@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T111923
LAST-MODIFIED:20240227T145824
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240229T140000
DTEND;TZID=Europe/London:20240229T150000
SUMMARY:Medium-enhanced production of c-cbar pairs in jets
DESCRIPTION:Title: Medium-enhanced production of c-cbar pairs in jets\n\nA
bstract: The degrees of freedom of the high temperature phase of QCD matte
r produced in heavy-ion collisions can be studied through its interactions
with high-energy partons that are also produced in these collisions. The
medium broadens the momentum and degrades the energy of these partons\, wh
ich is observed as a suppression of the yield of high-energy jets and hadr
ons in heavy-ion collisions compared to a proton-proton baseline. These in
teractions can be characterized by medium-modification of the QCD splittin
g functions. We study the modification of the g->c-cbar splitting function
in the kinematic range accessible at the LHC. In addition to characterizi
ng the momentum broadening of the c-cbar pair\, we find that interactions
with the medium also enhance the rate of c-cbar production. We also propos
e an experimental signature of this enhancement through the rate of jets c
ontaining two D0 mesons in heavy-ion collisions.\n\nSpeaker:\n* Jasmine Br
ewer (University of Oxford)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83894-medium-enhanced-production-o
f-c-cbar-pairs-in-jets
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83896@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T112118
LAST-MODIFIED:20240227T100330
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240306T140000
DTEND;TZID=Europe/London:20240306T150000
SUMMARY:QCD under extreme conditions - How complex Langevin can help
DESCRIPTION:Title: QCD under extreme conditions - How complex Langevin ca
n help\n\nAbstract: \n\nThe phase structure of quark matter is essential
for understanding the early time of the universe and the formation of matt
er in the universe. Computer simulations are crucial to guide and compleme
nt the extensive search for heavy-ion collision experiments around the wor
ld. Surprisingly\, very little is known about the phase diagram of the str
ong force under extreme conditions. The strong interaction is expected to
have a rich phase structure in the baryon chemical potential µ and temper
ature T plane.\n\nComplex Langevin simulations provide an ab initio method
to circumvent the sign problem at nonzero baryon density entirely since i
t is not based on importance sampling but rather on a stochastic explorati
on of an enlarged configuration space. We use complex Langevin simulations
to study the QCD phase diagram with two light quark flavours. In this stu
dy\, we use Wilson fermions with an intermediate pion mass of ~480 MeV. By
studying thermodynamic quantities\, in particular at lower temperatures\,
we are able to describe the equation of state.\n\nSpeaker:\n* Benjamin J
äger (University of Southern Denmark)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83896-qcd-under-extreme-conditions
-how-complex-langevin-can-help
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83898@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T112215
LAST-MODIFIED:20240311T081200
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240313T140000
DTEND;TZID=Europe/London:20240313T150000
SUMMARY:Landau Singularities from Whitney Stratifications
DESCRIPTION:Title: \n\nLandau Singularities from Whitney Stratifications\
n\nAbstract: \n\nAt the heart of both cross-section calculations at the L
arge Hadron Collider and gravitational wave physics lie the evaluation of
Feynman integrals. These integrals are multivalued meromorphic functions o
f the kinematic variables they depend on\, and understanding their analyti
c structure has been an ongoing quest for theoretical physicists for over
60 years. In this talk I will demonstrate how the complete set of singula
rities of these integrals may be explicitly obtained from the Whitney stra
tification of an algebraic map and provide a software implementation. This
stratification contains a lot of information and does not only describe t
he singularities of a given integral but also those of integrals obtained
from kinematic limits.\n\nSpeaker:\n* Felix Tellander (DESY)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83898-landau-singularities-from-wh
itney-stratifications
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-84024@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240322T094421
LAST-MODIFIED:20240401T070134
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240403T140000
DTEND;TZID=Europe/London:20240403T150000
SUMMARY:Quantum Simulation and Fully Gauged-Fixed Hamiltonians
DESCRIPTION:Title: Quantum Simulation and Fully Gauged-Fixed Hamiltonians\
n\nAbstract: Constrained Hamiltonians are ubiquitous in fundamental physic
s\, as any gauge theory will result in such a Hamiltonian.\n Unfortunately
\, implementing these Hamiltonians on digital quantum computers poses a nu
mber of difficulties\, both theoretical and\n practical. In this talk\,
I will discuss my recent work on constructing and implementing fully gauge
d-fixed Hamiltonians for\n SU(2) lattice gauge theories onto quantum hardw
are. In particular\, I present a generic method for fixing gauge symmetrie
s\, as well as a computational basis that is well-suited for near-continuu
m physics. The resultant Hamiltonian\, while more non-local than the origi
nal Hamiltonian without any gauge fixing\, is not prohibitively expensive
to implement\; this goes against the common lore that any gauge-fixed Hami
ltonian will suffer from a disastrous growth in non-locality.\n\nSpeaker:\
n* Dorota Grabowska (Washington University)
LOCATION:Room 5326\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/84024-quantum-simulation-and-fully
-gauged-fixed-hamiltonians
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-84034@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240407T132333
LAST-MODIFIED:20240407T160126
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240408T153000
DTEND;TZID=Europe/London:20240408T170000
SUMMARY:Meson spectroscopy in QCD
DESCRIPTION:Title: Meson spectroscopy in QCD\n\nAsbtract: I will show ho
w lattice QCD calculations can be used to study the excited meson spectrum
as it appears in experiments\, as short-lived resonances\, typically dec
aying into multiple final states. By evaluating coupled-channel scattering
amplitudes and analysing their pole content\, we come to a first-princip
les determination of excited states with minimal model-dependence. \n\nSp
eaker:\n* Jozef Dudek (College of William and Mary)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/84034-meson-spectroscopy-in-qcd
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83900@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T112341
LAST-MODIFIED:20240408T081754
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240410T140000
DTEND;TZID=Europe/London:20240410T150000
SUMMARY:Crafting chiral Lagrangians: the MINIBAR approach
DESCRIPTION:Title: Crafting chiral Lagrangians: the MINIBAR approach\n\nA
bstract: The low-energy dynamics of the strong force are captured by Chir
al Perturbation Theory (ChPT)\, an effective field theory based on the sym
metries of Quantum Chromodynamics. As an effective field theory\, it allow
s for progressively improvable descriptions through the inclusion of highe
r-order Lagrangians. In this seminar\, ChPT will be introduced along with
the derivation of the anomalous chiral Lagrangian at next-to-next-to-leadi
ng order (p^8). For this purpose\, we will present the software MINIBAR: t
ools to calculate minimal operator bases rapidly with Mathematica. With it
\, another example of chiral Lagrangian will be explored\, this time compu
ting the effective couplings of pseudoscalar mesons to gravity\, a step to
wards extracting their gravitational form factors.\n\nSpeaker:\n* Joan Rui
z-Vidal (Lund University)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83900-crafting-chiral-lagrangians-
the-minibar-approach
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-84016@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240312T163012
LAST-MODIFIED:20240404T163841
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240411T140000
DTEND;TZID=Europe/London:20240411T150000
SUMMARY:Factorization and resummation at next-to-leading power for amplitu
des and cross sections
DESCRIPTION:Title: Factorization and resummation at next-to-leading powe
r for amplitudes and cross sections\n\nAbstract: In recent years we have l
earned a lot about the structure of QCD amplitudes and cross sections once
one goes beyond the eikonal approximation. In this talk I will review thi
s progress\, addressing in particular the issue of predictive power\, fact
orization and resummation of NLP effects. I will also show the impact of s
uch effects on Higgs and Drell-Yan cross sections.\n\nSpeaker:\n* Eric Lae
nen (NIKHEF and Amsterdam University)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/84016-factorization-and-resummatio
n-at-next-to-leading-power-for-amplitudes-and-cross-sections
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83902@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T112728
LAST-MODIFIED:20240110T142359
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240417T140000
DTEND;TZID=Europe/London:20240417T150000
SUMMARY:Gauge Invariance and Observables in Particle Physics
DESCRIPTION:Title: Gauge Invariance and Observables in Particle Physics\n
\nAbstract: \n\nOn a formal\, fundamental level in a non-Abelian gauge th
eory only\n composite fields can be gauge-invariant\, rather than the elem
entary\n fields employed in perturbation theory. While at first sight in\n
contradiction to the phenomenological success of perturbation theory in\n
electroweak physics\, there is a deeper reason for both being compatible\
,\n the Fröhlich-Morchio-Strocchi mechanism. Its working and validity has
\n been demonstrated explicitly in lattice simulations. However\, even the
n\n this leaves still room for new phenomena in the standard model.\n More
over\, the standard model is special. Beyond the standard model these\n is
sues yield qualitative changes and affect such varied scenarios like\n gra
nd-unified theories\, supersymmetry\, and quantum gravity.\n The talk prov
ides an overview of the underlying mechanisms\, including\n some lattice r
esults in their support\, and finally highlights a few\n example applicati
ons.\n \n\nSpeaker:\n* Axel Maas (University of Graz)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83902-gauge-invariance-and-observa
bles-in-particle-physics
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83979@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240215T131307
LAST-MODIFIED:20240422T101547
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240422T140000
DTEND;TZID=Europe/London:20240422T150000
SUMMARY:Complete NLO QCD Corrections to ZZ Production in Gluon Fusion
DESCRIPTION:We calculate the complete NLO QCD corrections to loop-induced
gg → ZZ production including full top-quark mass effects. The two-l
oop virtual corrections are obtained by combining analytic results for the
massless\, Higgs-mediated\, and one-loop factorizable contributions with
numerically computed amplitudes containing the top-quark mass. We show tha
t the choice of subtraction scheme for the virtual contribution impacts th
e precision with which the virtual contribution must be evaluated in order
to obtain sufficiently precise phenomenological predictions. For direct p
roduction through a massive top-quark loop\, we observe that the relative
NLO corrections are large. The direct massive and Higgs-mediated contribut
ions individually increase relative to the massless production at high dib
oson invariant mass\, but interfere destructively with each other. At the
Large Hadron Collider\, the NLO corrections to the gluon channel give a si
zable contribution to the pp → ZZ + X cross-section at N3LO.\n\nSp
eaker:\n* Bakul Agarwal (KIT)
LOCATION:Room 5326\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/83979-complete-nlo-qcd-corrections
-to-zz-production-in-gluon-fusion
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83904@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T112928
LAST-MODIFIED:20240419T133553
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240424T140000
DTEND;TZID=Europe/London:20240424T150000
SUMMARY:Multiparty entanglement and holography
DESCRIPTION:Entanglement plays a central role in our understanding of the
emergence of spacetime in holography. An interesting question is what role
different forms of entanglement play - in particular\, whether there is a
n important role for multiparty entanglement. I will discuss some work in
progress exploring signals of multiparty entanglement\, and their behaviou
r in multiboundary wormhole states. \n\nSpeaker:\n* Simon Ross (Durham Un
iversity)
LOCATION:Room 5326\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/83904-multiparty-entanglement-and-
holography
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83906@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T113048
LAST-MODIFIED:20240506T073850
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240508T140000
DTEND;TZID=Europe/London:20240508T150000
SUMMARY: A qubit regularization of asymptotic freedom without fine-tuning
DESCRIPTION:Title: A qubit regularization of asymptotic freedom without
fine-tuning\n Abstract:\n Other than commonly used Wilson’s regularizati
on of quantum field theories\, the regularizations that explore lattice mo
dels with a strictly finite local Hilbert space are becoming popular in th
e anticipation of the upcoming era of quantum simulations of QFTs. A promi
nent example is Euclidean qubit regularization\, which offers a natural wa
y to recover continuum QFTs that emerge via infrared fixed points of latti
ce theories. A non-trivial question is whether we can also recover the phy
sics of ultraviolet fixed points\, using such regularizations. Specificall
y\, can we recover massive continuum QFTs which are free in the UV but con
tain a marginally relevant coupling?\n In this talk\, I will discuss a mic
roscopic model with two layers of dimers with an interlayer dimer fugacity
\, that captures both the asymptotically free UV physics and the massive l
ow-energy physics of the two-dimensional QFT near the Berezinskii-Kosterli
tz-Thouless (BKT) phase transition. We find evidence for a renormalization
group flow in our model\, where asymptotic freedom arises as a crossover
critical phenomenon near the quantum critical point and without fine-tunin
g. Furthermore\, I’ll show that some of the universal quantities at the
BKT transition show smaller finite size effects in our model as compared t
o the traditional XY model. Our model is a prime example of qubit regulari
zation of an asymptotically free massive QFT in Euclidean space-time and w
ill hopefully motivate the search for similar models with exotic RG flows
that may describe asymptotic freedom of non-Abelian gauge theories and in
particular QCD.\n\nSpeaker:\n* Marina Marinkovic (ETH Zürich)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83906-a-qubit-regularization-of-as
ymptotic-freedom-without-fine-tuning
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83908@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T113321
LAST-MODIFIED:20240513T115028
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240515T130000
DTEND;TZID=Europe/London:20240515T150000
SUMMARY:Nonlinear Effects in the Black Hole Ringdown
DESCRIPTION:Title: Nonlinear Effects in the Black Hole Ringdown\n\nAbstrac
t: Gravitational-wave observations of black hole ringdowns are commonly us
ed to characterize binary merger remnants and to test general relativity.
These analyses assume linear black hole perturbation theory\, in particula
r that the ringdown can be described in terms of quasinormal modes even fo
r times approaching the merger. Here we investigate a nonlinear effect dur
ing the ringdown\, namely how a mode excited at early times can excite add
itional modes as it is absorbed by the black hole. Using nonlinear simulat
ions\, we study the ringdown of a spherically-symmetric scalar field aroun
d an asymptotically anti-de Sitter black hole\, and we find that this "abs
orption-induced mode excitation" (AIME) is the dominant nonlinear effect.
I will show our current progress for looking for these nonlinearities in c
urrent waveform models and the need to provide flexible nonlinear models.
\n\nSpeaker:\n* Pablo Bosch (University of Amsterdam)
LOCATION:Room 4325B\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/83908-nonlinear-effects-in-the-bla
ck-hole-ringdown
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83919@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240115T173346
LAST-MODIFIED:20240306T111914
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240522T140000
DTEND;TZID=Europe/London:20240522T150000
SUMMARY:Testing Entanglement and Bell Inequalities at the LHC
DESCRIPTION:Title:\n\nTesting Entanglement and Bell Inequalities at the LH
C\n\nAbstract:\n\nLocality\, reality and measurement have been central que
stions in Quantum Mechanics since its first formulation. Empirical tests a
ddressing these issues were first proposed by John Bell in 1964. Subsequen
t experiments in atomic and optical systems (awarded the Nobel prize for p
hysics 2022) have been found to agree with the quantum predictions at ~eV
energies\, and to disagree with local hidden-variable theories. I’ll dis
cuss how\, by exploiting developments from the field of quantum computing\
, we can now also conceive of extending these tests to high-energy systems
such as Higgs boson decays.\n\nSpeaker:\n* Alan Barr (University of Oxfor
d)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83919-testing-entanglement-and-bel
l-inequalities-at-the-lhc
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83910@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240110T113503
LAST-MODIFIED:20240515T104938
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240527T140000
DTEND;TZID=Europe/London:20240527T150000
SUMMARY:Nuclear PDFs after 10 years of LHC data
DESCRIPTION:Title: Nuclear PDFs after 10 years of LHC data\n\nAbstract: W
e discuss the conceptual basis\, present knowledge and recent progress in\
n the field of global analysis of nuclear parton distribution functions\n
(PDFs). After introducing the theoretical foundations and methodological\n
approaches for the extraction of nuclear PDFs from experimental data\, we
\n review how different measurements in fixed-target and collider experime
nts\n provide increasingly precise constraints on various aspects of nucle
ar\n PDFs\, including shadowing\, antishadowing\, the EMC effect\, Fermi m
otion\,\n flavor separation\, deuteron binding\, target-mass and other hig
her-twist\n effects. Particular emphasis is given to measurements carried
out in\n proton-lead collisions at the Large Hadron Collider\, which have\
n revolutionized the global analysis during the past decade. These\n measu
rements include electroweak-boson\, jet\, light-hadron\, and\n heavy-flavo
r observables. We also outline the expected impact of the\n future Electro
n Ion Collider and discuss the role and interplay of nuclear\n PDFs with o
ther branches of nuclear\, particle and astroparticle physics.\n\nSpeaker:
\n* Michael Klasen (University of Münster)
LOCATION:Room 5326\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/83910-nuclear-pdfs-after-10-years-
of-lhc-data
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-83923@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240116T094713
LAST-MODIFIED:20240603T140044
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240604T140000
DTEND;TZID=Europe/London:20240604T150000
SUMMARY:Not one but two renormalizable theories of gravity
DESCRIPTION:Title: \n\nNot one but two renormalizable theories of gravity
\n\nAbstract: \n\nSecond-order-derivative plus fourth-order-derivative gr
avity is the ultraviolet completion of second-order-derivative quantum Ein
stein gravity. While it achieves renormalizability through states of negat
ive Dirac norm\, the unitarity violation that this would entail can be pos
tponed to Planck energies. As we show in this paper the theory has a diffe
rent problem\, one that occurs at all energy scales\, namely that the Dira
c norm of the vacuum of the theory is not finite. To establish this we pre
sent a procedure for determining the norm of the vacuum in any quantum fie
ld theory. With the Dirac norm of the vacuum of the second-order-derivativ
e plus fourth-order-derivative theory not being finite\, the Feynman rules
that are used to establish renormalizability are not valid\, as is the as
sumption that the theory can be used as an effective theory at energies we
ll below the Planck scale. This lack of finiteness is also manifested in t
he fact that the Minkowski path integral for the theory is divergent. Beca
use the vacuum Dirac norm is not finite\, the Hamiltonian of the theory is
not Hermitian. However\, it turns out to be $CPT$ symmetric. And when one
continues the theory into the complex plane and uses the $CPT$ symmetry i
nner product\, viz. the overlap of the left-eigenstate of the Hamiltonia
n with its right-eigenstate\, one then finds that for the vacuum this norm
is both finite and positive\, that the Feynman rules now are valid\, that
the Minkowski path integral now is well behaved\, and thus the theory now
can serve as a low energy effective theory. Consequently\, the theory can
now be offered as a fully consistent\, unitary and renormalizable theory
of quantum gravity. By analogous reasoning pure fourth-order derivative gr
avity is a fully consistent quantum gravity theory in its own right. \n\n
\n\nFor a Zoom link: Please email nils.hermansson-truedsson [at] ed.ac.uk
if you would like to attend remotely via Zoom. \n\nSpeaker:\n* Philip Man
nheim (University of Connecticut)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/83923-not-one-but-two-renormalizab
le-theories-of-gravity
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-84672@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240517T154842
LAST-MODIFIED:20240603T182314
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240605T130000
DTEND;TZID=Europe/London:20240605T140000
SUMMARY:Fermionic theories and dualities in 2+1 dimensions
DESCRIPTION:Title: Fermionic theories and dualities in 2+1 dimensions\n\n
Abstract: Dirac fermions and their self-interactions play a key role in p
article physics and condensed matter\, and exhibit interesting phenomena
such as universality at conformal critical points\, chiral symmetry breaki
ng\, and the dynamical generation of fermion mass. In this talk\, I discus
s critical Gross-Neveu theories in 2+1 dimensions using the renormalisatio
n group. After introducing the method of functional renormalisation and it
s application to U(N) fermionic theories\, I will demonstrate how classica
lly irrelevant six-fermion interactions become exactly marginal at large N
\, leading to a line of UV fixed points. At the endpoints of this line\, m
ass is generated spontaneously following the breaking of scale symmetry\,
in a manner reminiscent of the Bardeen-Moshe-Bander phenomenon in scalar O
(N) theories. I will further discuss aspects of chiral symmetry breaking a
nd the dynamical generation of fermion mass\, and an exact duality map bet
ween Gross-Neveu and Gross-Neveu-Yukawa theories.\n\nSpeaker:\n* Charlie C
resswell-Hogg (University of Sussex)
LOCATION:Room 6201\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/84672-fermionic-theories-and-duali
ties-in-21-dimensions
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-84720@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240614T151418
LAST-MODIFIED:20240614T210354
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240619T140000
DTEND;TZID=Europe/London:20240619T150000
SUMMARY:Twisted Tools for (Untwisted) Quantum Field Theory
DESCRIPTION:One of the most important properties of quantum field theories
is that they can be deformed by "turning on interactions." Indeed\, essen
tially every observable can be viewed as coupling the theory to some exter
nal system. Famously\, such interactions will (generically) break scale in
variance\, leading to familiar ideas of EFTs and RG flows in the space of
QFTs. An underappreciated fact is that one can actually consider flows ge
nerated by any transformation\, not just the usual scale transformations
. \n\n\n\nIn my talk\, I will discuss a flow in the space of QFTs coming
from (an analogue of) BRST symmetry. The beta-function for this BRST-flow
controls deformations of the QFT and is highly mathematically constrained
\, generating a "homotopical" generalization of a Lie algebras in any QFT.
These "homotopical" Lie brackets are highly computable (requiring only a
first course in QFT to compute) and contain familiar information such as a
nomalies and Operator Product Expansion coefficients. Time permitting\, I
will discuss how these brackets are even more strongly constrained in holo
morphic/topological theories\, and prove the absence of perturbative corre
ctions to HT theories with more than one topological direction. Based on a
rXiv:2403.13049.\n\nSpeaker:\n* Dr Justin Kulp (Stony Brook)
LOCATION:Room 4325B\, JCMB
URL:https://www.ph.ed.ac.uk/events/2024/84720-twisted-tools-for-untwisted-
quantum-field-theory
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-84041@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240416T083455
LAST-MODIFIED:20240529T160712
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240620T140000
DTEND;TZID=Europe/London:20240620T150000
SUMMARY:Axion dark matter: crisis and opportunity
DESCRIPTION:Axions are an increasingly popular dark matter candidate with
a flourishing experimental campaign now poised to discover them if they ex
ist. However there is a potential crisis lurking within this model which c
ould make a discovery impossible\, even the axion does turn out to be the
correct dark matter candidate. In one of the general classes of cosmologi
cal production scenarios—namely the scenario in which the axion is born
after inflation—it has been known for some time that dark matter is e
xpected to inherit ultra-small-scale inhomogeneities from dynamics of the
field taking place at the QCD scale. These inhomogeneities eventually coll
apse under gravity into small-scale structures called miniclusters or mini
halos\, which have potentially drastic consequences for experimental effor
ts to detect the axion on Earth. In this talk\, I will overview the field
of axion cosmology—how we can predict the properties the axion must have
if it is to explain dark matter. I will also discuss some recent work whi
ch aims to address the degree of substructure in the axion dark matter dis
tribution and attempt to quantify the extent to which prospects for discov
ering axions experimentally are hindered or potentially doomed altogether.
\n\n\nSpeaker:\n* Ciaran O'Hare (University of Sydney)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/84041-axion-dark-matter-crisis-and
-opportunity
END:VEVENT
BEGIN:VEVENT
CLASS:PUBLIC
UID:EVENT-84663@www.ph.ed.ac.uk
DTSTAMP:20240623T014551
CREATED:20240513T144611
LAST-MODIFIED:20240513T144644
STATUS:CONFIRMED
DTSTART;TZID=Europe/London:20240717T140000
DTEND;TZID=Europe/London:20240717T150000
SUMMARY:TBA
DESCRIPTION:Title: TBA\n\nAbstract: TBA\n\nSpeaker:\n* Joshua Crawford (Un
iversity of Adelaide)
LOCATION:Higgs Centre Seminar Room\, Room 4305\, James Clerk Maxwell Build
ing (JCMB)
URL:https://www.ph.ed.ac.uk/events/2024/84663-tba
END:VEVENT
END:VCALENDAR