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SUMMARY:Aaron Vincent (Queen's University\, Arthur McDonald Astroparticle
Institute)
DTSTART:20200604T190000Z
DTEND:20200604T200000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/1
DESCRIPTION:Title: Very small black holes at very large experiments\nby Aaron
Vincent (Queen's University\, Arthur McDonald Astroparticle Institute) as
part of Winnipeg Institute for Theoretical Physics Seminar\n\n\nAbstract\
nThe existence of Large Extra Dimensions has been an intriguing prospect s
ince they were first suggested. In such scenarios\, the “true” Planck
mass can be as low as a few TeV\, and much of the large discrepancy betwee
n the observed Planck scale and the electroweak scale can be explained by
geometric effects. One of the more tantalizing signatures of such scenario
s is the creation of microscopic black holes in collisions of high-energy
particles. I will first describe the reach of the next generation of neutr
ino observatories\, which can probe energies far in excess of the LHC\, an
d will describe the novel experimental signatures of microscopic black hol
es in neutrino telescopes like IceCube Gen2. I will end by showing that\,
if LEDs can be also probed at future colliders such as the FCC\, these bla
ck holes can be used to detect and constrain dark matter — or any dark s
ector particle lighter than a few TeV — regardless of its coupling to th
e standard model.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cristina Bena (Universite Paris-Saclay\, IPhT)
DTSTART:20200707T150000Z
DTEND:20200707T160000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/2
DESCRIPTION:Title: Majorana and other boundary modes from impurity states via T-m
atrix\nby Cristina Bena (Universite Paris-Saclay\, IPhT) as part of Wi
nnipeg Institute for Theoretical Physics Seminar\n\n\nAbstract\nWe provide
a new and exact formalism to describe the formation of end\, edge or surf
ace states through the evolution of impurity-induced states. We propose a
general algorithm that consists of finding the impurity states via the T-m
atrix formalism and showing that they evolve into boundary modes when the
impurity potential goes to infinity. We apply this technique to obtain Maj
orana states\, topological insulator edges states and graphene edges state
s. We also show that this approach provides us with a new direct and non-n
umerical technique to obtain the surface Green's functions for three-dimen
sional systems and we apply it to Weyl semimetals.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Omer Blaes (UCSB)
DTSTART:20200722T203000Z
DTEND:20200722T213000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/3
DESCRIPTION:Title: Magnetohydrodynamics and Convection in Accretion Disks: From
Dwarf Novae to Luminous Quasars\nby Omer Blaes (UCSB) as part of Winni
peg Institute for Theoretical Physics Seminar\n\n\nAbstract\nOne of the mo
st powerful sources of energy in the universe is the liberation of gravita
tional binding energy as plasma falls into a central object\, such as a bl
ack hole. Such accretion flows are dynamically complex\, involving signif
icant rotational support against gravity\, transport of angular momentum b
y magnetic turbulence\, and turbulent dissipation. Simulations of these p
rocesses have had a checkered history of explaining observed accretion pow
ered sources in the universe. In this talk\, I will show how an additiona
l complicating factor\, opacity-driven convection\, actually has a profoun
d effect on the dynamics of these flows\, and might provide an explanation
for a variety of observed phenomenology in luminous accretion flows aroun
d white dwarfs and supermassive black holes.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ada Chan (York)
DTSTART:20200812T200000Z
DTEND:20200812T210000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/4
DESCRIPTION:Title: Spectra properties of graphs and their quantum walks\nby A
da Chan (York) as part of Winnipeg Institute for Theoretical Physics Semin
ar\n\n\nAbstract\nIn this talk\, we focus on the continuous-time quantum w
alk on graphs. We discuss three phenomena of the quantum walks: the abilit
y of perfect transmission of information from one qubit to another\, calle
d perfect state transfer\; the generation of entanglement between two qubi
ts\, called fractional revival\; and reaching uniform distribution at a ce
rtain time\, called instantaneous uniform mixing.\n\nWe use tools in algeb
raic graph theory to show the existence of graphs admitting some of these
phenomena at arbitrarily small times.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Robert Brandenberger (McGill University)
DTSTART:20201120T183000Z
DTEND:20201120T193000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/5
DESCRIPTION:Title: Stephen Hawking - A Personal Perspective\nby Robert Brande
nberger (McGill University) as part of Winnipeg Institute for Theoretical
Physics Seminar\n\n\nAbstract\nStephen Hawking was one of the leading theo
retical physicists of his generation. I will give an overview of his groun
d-breaking contributions to science. I had the good fortune of being a pos
tdoc in Stephen's group for two years\, and I will try to describe some of
my strong impressions of him as a person.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Seyda Ipek (Carleton University)
DTSTART:20211005T170000Z
DTEND:20211005T180000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/6
DESCRIPTION:Title: Why are we here? Matter -- antimatter asymmetry of the univers
e\nby Seyda Ipek (Carleton University) as part of Winnipeg Institute f
or Theoretical Physics Seminar\n\n\nAbstract\nThe Standard Model of elemen
tary particles predicts that there should be equal amounts of matter and a
ntimatter in our universe. However everything around us\, rocks\, stars\,
galaxies\, etc. is made up of “matter” and not “antimatter”. What
happened to the antimatter in the Universe? This matter--antimatter asymme
try is a clear sign of new physics beyond the Standard Model. I will expla
in the new physics required for generating such an asymmetry and I will ta
lk about specific models that do the job.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Evan McDonough (University of Winnipeg)
DTSTART:20220128T183000Z
DTEND:20220128T193000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/7
DESCRIPTION:Title: The Light and Fuzzy Side of Dark Matter\nby Evan McDonough
(University of Winnipeg) as part of Winnipeg Institute for Theoretical Ph
ysics Seminar\n\n\nAbstract\nThe identity of dark matter remains a mystery
\, despite decades of theorizing and detection efforts. This includes the
mechanism for its primordial production\, its interactions with itself or
with visible matter\, and the very nature of dark matter\, which could ran
ge from a Bose-Einstein Condensate\, to Black Holes\, to a traditional par
ticle. In this talk I will discuss new ideas for dark matter\, and how to
experimentally test these ideas. I will focus on dark matter in the extrem
e low mass range\, which may exhibit exciting new phenomena\, such as exot
ic phases of matter and vortex formation. These models can be tested in a
wide array of experimental arenas\, ranging from the large scale structure
of the universe to particle physics experiments\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jose Ezquiaga (University of Chicago)
DTSTART:20220217T180000Z
DTEND:20220217T190000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/8
DESCRIPTION:Title: The gravitational wave universe through the lens\nby Jose
Ezquiaga (University of Chicago) as part of Winnipeg Institute for Theoret
ical Physics Seminar\n\n\nAbstract\nAs the horizon of our gravitational wa
ve (GW) detectors extends to higher redshifts\, the chances that distant G
Ws encounter some intervening matter distribution increase significantly.
If a GW passes close enough to a galaxy\, multiple images of the same so
urce will be produced\, arriving at our detectors at different times and w
ith different amplitudes and phases. In this talk I will describe current
searches for multiply lensed GW images and their challenges. I will also s
how how strongly lensed events could be identified with a single image if
waveform distortions are identified\, and how these distortions might be c
onfused with modified gravity if the search pipeline does not include lens
ed templates. Lensed GWs will provide unique information to constrain the
matter distribution in the universe and will be one of the main targets of
next generation detectors.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nils Deppe (California Institute of Technology)
DTSTART:20220317T170000Z
DTEND:20220317T180000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/9
DESCRIPTION:Title: Challenges for accurate gravitational wave astrophysics predic
tions\nby Nils Deppe (California Institute of Technology) as part of W
innipeg Institute for Theoretical Physics Seminar\n\n\nAbstract\nThe first
detection of a binary neutron star merger through gravitational waves too
k place in 2017. The event was accompanied by counterpart detections all a
cross the electromagnetic spectrum and established that such events can pr
oduce short gamma-ray bursts and heavy elements. Despite the tremendous su
ccess\, our ability to model such merger events remains a major limiting f
actor in understanding these rich high-energy collisions. The errors in nu
merical simulations of binary neutron star mergers are larger than experim
ental errors and difficult to quantify. Additionally\, while binary black
hole simulations are sufficiently accurate for current observatories like
LIGO\, this will no longer be true for the next-generation ground-based gr
avitational-wave observatories like Cosmic Explorer and Einstein Telescope
. I will discuss recent work combining breakthroughs in parallel computing
and numerical algorithms that are necessary to take full advantage of cur
rent and future multimessenger gravitational wave detections.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Buchel (Western Ontario/Perimeter Institute)
DTSTART:20220606T160000Z
DTEND:20220606T170000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/10
DESCRIPTION:Title: Dynamical fixed points in strongly coupled holographic system
s\nby Alex Buchel (Western Ontario/Perimeter Institute) as part of Win
nipeg Institute for Theoretical Physics Seminar\n\n\nAbstract\nTypically\,
an interactive system evolves towards thermal equilibrium\, with hydrodyn
amics representing a universal framework for its late-time dynamics. Class
ification of the dynamical fixed points (DFPs) of a driven Quantum Field T
heory (with time dependent coupling constants\, masses\, external backgrou
nd fields\, etc.) is unknown. We use holographic framework to analyze such
fixed points in one example of strongly coupled gauge theory\, driven by
homogeneous and isotropic expansion of the background metric - equivalentl
y\, a late-time dynamics of the corresponding QFT in Friedmann-Lemaitre-Ro
bertson-Walker Universe. We identify DFPs that are perturbatively stable\,
and those that are perturbatively unstable\, computing the spectrum of th
e quasinormal modes in the corresponding holographic dual. We further demo
nstrate that a stable DFP can be unstable non-perturbatively\, and explain
the role of the entanglement entropy density as a test for a non-perturb
ative stability. Finally\, we demonstrated that a driven evolution might n
ot have a fixed point at all: the entanglement entropy density of a system
can grow without bounds.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kyle Shiells (University of Manitoba)
DTSTART:20221103T193000Z
DTEND:20221103T203000Z
DTSTAMP:20260404T111325Z
UID:WITP-seminar/11
DESCRIPTION:Title: Nuclear Femtography: probing the inside of the nucleon\nb
y Kyle Shiells (University of Manitoba) as part of Winnipeg Institute for
Theoretical Physics Seminar\n\n\nAbstract\nAround the turn of the millenni
um\, exciting new ways to study hadronic structure were proposed. The so-c
alled Generalized parton distribution functions (GPDs) hold unprecedented
information about the structure of hadrons. For instance\, they can tell u
s how the proton and neutron acquire their observable spin of 1/2 through
what are called spin sum rules. In the first part of this talk I will disc
uss some of the important physics of GPDs\, including spin sum rules\, foc
using on ones which are most accessible experimentally. GPDs however\, can
only be probed from a relatively new line of challenging deeply virtual e
xclusive scattering experiments. One such flagship process for doing so is
Deeply Virtual Compton scattering. I will highlight the phenomenological
relationship between these observables and the GPDs. The greater scheme of
the global extraction of GPDs will also heavily rely on available and upc
oming lattice QCD data\, making it unique to the previous global analyses
seen in the extraction of parton distribution functions from deep inelasti
c scattering processes. I will discuss our approach to modelling and extra
cting the GPDs from these global constraints\, which involves a unique app
lication of complex analysis and non-linear fitting techniques.\n
LOCATION:https://stable.researchseminars.org/talk/WITP-seminar/11/
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