BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Roland Bittleston (Perimeter Institute)
DTSTART:20230615T003000Z
DTEND:20230615T013000Z
DTSTAMP:20260422T214712Z
UID:nmps/1
DESCRIPTION:Title: Ove
rview of Classical and Quantum Integrability in Four Dimensions\nby Ro
land Bittleston (Perimeter Institute) as part of Nagoya Math-Phys Seminar\
n\n\nAbstract\nThis talk will review recent progress by a number of groups
in understanding classical and quantum integrable models in four dimensio
ns. This has been achieved by exploiting twistor methods. After a short in
troduction to twistors\, I will introduce some of the simplest examples of
4d theories with twistor uplifts: self-dual Yang-Mills and the 4d WZW mod
el. I then plan to touch on a number of topics including: the connection t
o 4d Chern-Simons theory\, quantization of these theories on twistor space
\, their hidden symmetry algebras (also known as celestial chiral algebras
) and finally the twistor string.\n
LOCATION:https://researchseminars.org/talk/nmps/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roland Bittleston (Perimeter Institute)
DTSTART:20230616T003000Z
DTEND:20230616T013000Z
DTSTAMP:20260422T214712Z
UID:nmps/2
DESCRIPTION:Title: Cla
ssical and Quantum Integrability in Self-Dual Gravity\nby Roland Bittl
eston (Perimeter Institute) as part of Nagoya Math-Phys Seminar\n\n\nAbstr
act\nThis talk will concentrate on an intriguing example of a 4d integrabl
e theory: self-dual gravity. I will explain how its classical integrabilit
y is realised in the existence of an infinite dimensional hidden symmetry
algebra\, or celestial chiral algebra. This governs the universal holomorp
hic surface defect which can couple to the twistor uplift of self-dual gra
vity. At the quantum level\, this twistor uplift is anomalous and the quan
tum corrected chiral algebra fails to be associative. I will present a num
ber of methods of cancelling the anomaly\, leading to consistent quantum c
orrected hidden symmetry algebras. Finally\, I will explore how this story
is modified on one of the simplest non-trivial examples of a self-dual Ri
cci flat background: the Eguchi-Hanson gravitational instanton.\n\nThis ta
lk is based on collaborations with Simon Heuveline\, Atul Sharma and David
Skinner.\n
LOCATION:https://researchseminars.org/talk/nmps/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Atul Sharma (Harvard University)
DTSTART:20230721T003000Z
DTEND:20230721T013000Z
DTSTAMP:20260422T214712Z
UID:nmps/3
DESCRIPTION:Title: Bur
ns holography\nby Atul Sharma (Harvard University) as part of Nagoya M
ath-Phys Seminar\n\n\nAbstract\nI will describe a top-down example of cele
stial holography\, based on recent work with Costello and Paquette. Our du
ality relates certain models of self-dual gauge theory and conformal gravi
ty\, placed on an asymptotically flat four-dimensional spacetime called Bu
rns space\, to a two-dimensional chiral algebra living on D1 branes in a t
opological string theory on twistor space.\n
LOCATION:https://researchseminars.org/talk/nmps/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Frank Nijhoff (University of Leeds)
DTSTART:20230914T080000Z
DTEND:20230914T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/4
DESCRIPTION:Title: Lag
rangian multiforms\, the Darboux-KP system and Chern-Simons theory in infi
nite-dimensional space\nby Frank Nijhoff (University of Leeds) as part
of Nagoya Math-Phys Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/nmps/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Francis Howard (Benin University)
DTSTART:20231019T080000Z
DTEND:20231019T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/5
DESCRIPTION:Title: Par
ticles and p－Adic Integrals of Spin(1/2): Spin Lie Group\, R(ρ\, q)－g
amma and R(ρ\, q)－ beta Functions\, Ghost and Applications\nby Fran
cis Howard (Benin University) as part of Nagoya Math-Phys Seminar\n\nAbstr
act: TBA\n
LOCATION:https://researchseminars.org/talk/nmps/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Artur Sergyeyev (Opava)
DTSTART:20231109T080000Z
DTEND:20231109T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/6
DESCRIPTION:Title: Inf
initely many new (3+1)-dimensional integrable systems from contact geometr
y\nby Artur Sergyeyev (Opava) as part of Nagoya Math-Phys Seminar\n\nA
bstract: TBA\n
LOCATION:https://researchseminars.org/talk/nmps/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Meer Ashwinkumar (University of Bern)
DTSTART:20231221T080000Z
DTEND:20231221T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/7
DESCRIPTION:Title: Dua
lities and Discretizations of Integrable Quantum Field Theories from 4d Ch
ern-Simons Theory\nby Meer Ashwinkumar (University of Bern) as part of
Nagoya Math-Phys Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/nmps/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yuri Suris
DTSTART:20240509T080000Z
DTEND:20240509T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/8
DESCRIPTION:Title: E.
Noether's variational symmetries and pluri-Lagrangian systems\nby Yuri
Suris as part of Nagoya Math-Phys Seminar\n\n\nAbstract\nWe analyze the r
elation of the notion of a pluri-Lagrangian system\, which recently emerge
d in the theory\nof integrable systems\, to the classical notion of variat
ional symmetry\, due to E. Noether. For finite-dimensional (classical mech
anical) systems we show that\, for any Lagrangian system with m commuting
variational symmetries\, one can construct a pluri-Lagrangian 1-form in th
e (m+1)-dimensional time\,\nwhose multi-time Euler-Lagrange equations coin
cide with the original system supplied with m commuting\nevolutionary flow
s corresponding to the variational symmetries. For two-dimensional hierarc
hies of\nLagrangian PDEs\, we show that if the flow of each PDE is a varia
tional symmetry of all others\, then there exists a pluri-Lagrangian 2-for
m for the hierarchy. The corresponding multi-time Euler–Lagrange equatio
ns coincide with the original system supplied with commuting evolutionary
flows induced by the variational symmetries.\n
LOCATION:https://researchseminars.org/talk/nmps/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Junya Yagi (Tsinghua)
DTSTART:20240913T080000Z
DTEND:20240913T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/9
DESCRIPTION:Title: 3D
integrability in gauge theories\nby Junya Yagi (Tsinghua) as part of N
agoya Math-Phys Seminar\n\n\nAbstract\nThe Zamolodchikov tetrahedron equat
ion is a fundamental relation for the integrability of 3D lattice models i
n statistical mechanics\, playing a role similar to the Yang-Baxter equati
on in 2D lattice models. I will discuss how solutions of the tetrahedron e
quation arise from dualities of supersymmetric gauge theories.\n
LOCATION:https://researchseminars.org/talk/nmps/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Richard Szabo
DTSTART:20250314T083000Z
DTEND:20250314T093000Z
DTSTAMP:20260422T214712Z
UID:nmps/10
DESCRIPTION:Title: Do
uble copy of noncommutative gauge theory\nby Richard Szabo as part of
Nagoya Math-Phys Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/nmps/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mats Vermeeren
DTSTART:20250718T080000Z
DTEND:20250718T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/11
DESCRIPTION:Title: La
grangian multiforms and conservation laws\nby Mats Vermeeren as part o
f Nagoya Math-Phys Seminar\n\n\nAbstract\nLagrangian multiform theory is a
variational principle for hierarchies of commuting differential equations
. Lagrangian 1-forms typically describe systems of commuting ODEs\, Lagran
gian 2-forms typically describe hierarchies of (1+1)-dimensional PDEs\, an
d so on. Typical examples include soliton hierarchies such as the KdV. In
these examples\, there is a close relation between the existence of a Lagr
angian multiform and the fact that the flows are variational symmetries of
each other.\n\n In this talk\, we give a number of examples of Lagrangian
multiforms that break this pattern. We will present Lagrangian 2-forms th
at can be interpreted as conservation laws for 3-dimensional PDEs. In thes
e examples\, the conservation Law does not arise via Noether's theorem fro
m a known Lagrangian. Almost the opposite is true: the construction of a L
agrangian multiform relies on the existence of a suitable conservation Law
for an equation that is not variational by itself.\n\nWe also give additi
onal examples of Lagrangian multiforms for dispersionless integrable syste
ms\, including some systems that arise via hydrodynamic reductions of Pleb
anski's second heavenly equation.\n
LOCATION:https://researchseminars.org/talk/nmps/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vincent Caudrelier
DTSTART:20260116T080000Z
DTEND:20260116T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/12
DESCRIPTION:Title: Cl
assical Yang-Baxter equation\, Lagrangian multiforms and ultralocal integr
able hierarchies\nby Vincent Caudrelier as part of Nagoya Math-Phys Se
minar\n\n\nAbstract\nI will first review the main ideas of Lagrangian mult
iform theory which provides a variational framework for integrable systems
\, focusing on 1+1 dimensional models. The key idea is to encode variation
ally the compatibility of the flows in an integrable hierarchy by introduc
ing a generalisation of standard Lagrangians and action functionals\, and
a corresponding generalisation of the principle of least action. \n\nI wil
l then present a systematic construction of Lagrangian multiforms for hier
archies of ultralocal field theories. The ''multitime'' Euler-Lagrange equ
ations produce the infinite collection of flatness equations for the Lax c
onnection. It is based on a few key (algebraic) ingredients\, the main one
being the classical r-matrix and the classical Yang-Baxter equation. In p
articular\, the construction casts the classical Yang-Baxter in a variatio
nal context for the first time. For simplicity of exposition\, I will focu
s on the simplest example of the so-called Ablowitz-Kaup-Newell-Segur hier
archy which already contains all the essential features (classical r-matri
x\, generating formalism). I will then explain briefly how these features
generalise to produce Lagrangian multiforms for many other (known and new)
hierarchies : e.g. Zakharov-Mikhailov\, Faddeev-Reshetikhin model\, defor
med sigma/Gross-Neveu models. Time permitting\, I will explain how one can
easily couple different hierarchies together to form new ones and obtain
the corresponding Lagrangian multiform.\n
LOCATION:https://researchseminars.org/talk/nmps/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Skinner (Cambridge)
DTSTART:20260220T080000Z
DTEND:20260220T090000Z
DTSTAMP:20260422T214712Z
UID:nmps/13
DESCRIPTION:Title: To
pological Strings on the Beach\nby David Skinner (Cambridge) as part o
f Nagoya Math-Phys Seminar\n\n\nAbstract\nThe KP equation is a well-known
classical integrable system that describes shallow water waves in 2+1 dime
nsions. While many integrable systems are known to arise from twistor spac
e\, the KP equation has long resisted this classification. Recently\, foll
owing ideas of Costello\, the KP equation has been shown to arise from a m
ixed topological-holomorphic Chern-Simons theory in 5d. This theory comes
complete with a chiral W-algebra and suggests that solitonic waves corresp
ond to holomorphic line bundles on non-commutative mini-twistor space.\n
LOCATION:https://researchseminars.org/talk/nmps/13/
END:VEVENT
END:VCALENDAR