Workshop Report

Extremely Big Eyes on the Early Universe at
Kavli IPMU
Alvio Renzini
Associate Scientis , INAF, Astronomical Observatory of Padova

John Silverman
Kavli IPMU Associate Professor

With the advent of giant telescopes
20 - 40m in diameter, the next
decade will see a transformational
phase for ground-based optical/nearinfrared astronomy. The constructionof three such telescopes has alreadystarted or will soon start: the Thirty
Meter Telescope (TMT), the Extremely
Large Telescope (ELT), and the Giant
Magellan Telescope (GMT), with theJapanese astronomical community
being a prominent member of theTMT. To promote alertness on theopportunities they offer for ourunderstanding of the distant Universe,
a three-part conference series started
with the kickoff meeting at UCLA thispast January, followed by the second
conference at Kavli-IPMU (March 25 29) while the third conference will beheld in Rome this September.
The workshop was attended
by over 70 participants from theAsia/Pacific region, US and Europe.
The status and capabilities of eachtelescope were reported, making

clear that, while the ELTs will comeafter several years of JWST (JamesWebb Space Telescope) operation,
still they will outperform it in variousways. First, being diffraction limited
thanks to advanced adaptive optics,
they will have 3 to 6 times better
spatial resolution, or just 20 - 40parsecs at redshift = 7. The ELTs will
also offer higher spectral resolution,access to shorter wavelengths, higher
spectroscopic multiplex and a much
longer lifetime.
These unparalleled capacities
will allow giant leaps forward in
our understanding of first galaxies
and cosmic reionization, of thecoevolution of galaxies and theircentral supermassive black holes,of the baryon cycle in and out
galaxies feeding star formation andspreading metals out of them, andof physical processes responsible forhalting star formation in galaxies.
The current state of the art wasillustrated in over 50 presentations,also emphasizing that galaxies must
be seen in the context of their large
scale environment . In this respect, thelarge surveys being conducted with
Subaru s Hyper-Suprime Cam andin the near future with the PrimeFocus Spectrograph are paving theway for the ELTs. We also heard
from theoreticians constructing everlarger and more detailed simulationsof galaxies and their need forobservational constraints from thenext generation of giant telescopes .
Several important issues emerged
and were discussed at the conference.
How to optimize the threetelescopes ensuring they together
cover the broadest possible rangeof capabilities, hence allowing thelargest variety of science programs?
Indeed, it will not be possible for eachindividual telescope to support all
the instruments that would exploit
its large aperture. Therefore, somecomplementary capability between
the three telescopes will be highly
beneficial, leaving then to theingenuity of the science teams to takeadvantage of them. Thus the ultimate
aim of the workshop was to lookforward from the current researchand prepare for the exciting future
opportunities offered to optical andnear-infrared astronomy.

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Workshop Report

Representation Theory, Gauge Theory andIntegrable Systems
Hiraku Nakajima
Kavli IPMU Principal Investigator

From Feb. 4 to Feb. 8, 2019,
Kavli IPMU hosted a workshop on
Representation theory, gauge theory
and integrable systems organized
by Hiraku Nakajima (Kavli IPMU),Francesco Sala (Kavli IPMU), Yuji
Tachikawa (Kavli IPMU), and Yutaka
Yoshida (Kavli IPMU). It was supported
in part by JSPS Grant Number
16H06335 and by financial support
from MEXT.
The workshop focuses interfaces
among representation theory, gauge
theory and integrable systems. There
have been numerous connections inrecent decades, such as computationof partition functions in gauge
theories via representation theory
and integrable systems, realizationof representations of quantum
algebras via moduli spaces in gauge
theories, new examples of quantum
algebras via gauge theory, and soon. The workshop brought together
mathematicians and physicists,including both experts and young
people in these related areas fromJapan and overseas to discuss new
developments and investigate
potential directions for future research.
The talks of Nekrasov, Bershtein,
and Yamazaki were devoted torelations between 4 or 5 dimensional
SUSY (supersymmetric) gauge theories
and isomonodromic deformation ofdifferential or difference equations,Painlevé equations. In particular,28

solutions of Painlevé equations aredescribed by gauge theory partition
functions, and bilinear relations,known as Hirota type equations,are derived from properties of SUSY
gauge theories.
The talks of Yanagida and Yang
were devoted to Hall algebras ofcategories of coherent sheaves ofcertain algebraic varieties. Yanagidaused coherent sheaves on abeliansurfaces and gave a new proof of thebispectral property of MacdonaldRuijsenaars difference operators
as an application. Yang studied
the cohomological Hall algebra forcoherent sheaves on
supported on
the union of coordinate 2-planes, andits relation to Yangian ofandthe vertex operator algebra recently
introduced by Gaiotto and Rapcak.
Hosseini and Okuda discussed
the formula of partition functions,given by the localization technique.
Hosseini s talk was devoted to thoseof 5-dimensional SUSY gauge theories
on a toric surface times the circle, andOkuda s talk was for line operators in
4-dimensional SUSY gauge theories.
Kanno explained representation
theory of quantum toroidal algebra, in particular, intertwiners
ofbetween its Fock representations.
They are related to the refined
topological vertex , the building
block of the refined version of the
topological string partition functionsKavli IPMU News No. 45 March 2019of toric Calabi-Yau 3-folds.
The talks of Gukov and Pei wereabout construction of modulartensor categories from a class of
4-dimensional SUSY quantum field
theories, and relation between
representation theories of vertex
operator algebras and geometry of
Coulomb branches.
McBreen and Hilburn talked
about mysterious relations between
Higgs and Coulomb branches of
3-dimensional SUSY gauge theories,
called symplectic duality. McBreen
proposed a categorical version of theHikita conjecture, which states anequivalence between the categories
associated with Higgs and Coulomb
branches. One of the categories is
supposed to be the derived categoryof constructible sheaves on the loop
space, whose rigorous foundation is achallenging problem. Hilburn explained
the relation between symplectic
duality and Langlands duality.
Langlands duality also appeared in the
talk of Hausel, where he explained
examples of branes in moduli spacesof Higgs bundles of a group and its
Langlands dual, and their relation
under the semiclassical limit of themirror symmetry.
The talks of Kato and Su weredevoted to the relation between
equivariant quantum K-theory/
cohomology and equivariant K-theory/
homology of affine Grassmannians.

Kato introduced the third object,
the equivariant K-theory of a semiinfinite flag variety, to connect themvigorously. Su, following the ideaof Teleman, defined the action of
the latter via shift operators acting
on quantum cohomology. Affine
Grassmannians are associated withfinite dimensional complex reductivegroups. There is a growing interest in
double affine Grassmannians, which
are affine Grassmannians for affine
Kac-Moody groups. Muthiah explainedan approach to define the analogous
double affine flag varieties and theirSchubert subvarieties. He discussed
Hecke algebras, Bruhat order, etc. inthis setting.
Kimura explained a definition ofquiver W-algebras associated with aquiver, based on qq-character definedvia 4d SUSY quiver gauge theories.
The talk of Appel was devoted to an
approach to the reflection equationand its solution K-matrices via thecategory of representations ofquantum symmetric pairs, constructed
as quantization of small K-matrices.
It was unfortunate that a few
invited speakers canceled their visits at
the last moment. But participants told
us that it was an exciting and fruitfulworkshop with many interestingtalks on hot topics. Personally, I wasvery happy to have a discussion on
Coulomb branches of gauge theories,and started a collaboration withparticipants.

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Workshop Report

Interdisciplinary Approach to Cancer Therapy
Pietro Caradonna
Kavli IPMU Postdoctoral Fellow

Shin ichiro Takeda
Kavli IPMU Assistant Professor

An important movement towards
discussion of urgent issues faced bymodern cancer research began on the27th of March. 70 researchers from 8
countries participated in a workshop
called the Interdisciplinary approachof applying cutting-edge technologies
at the frontier of cancer research .
Its objective was to understand thechallenges of eradicating cancer, andto report on the latest developmentsof cutting-edge technologies used inclinical applications.
Professor Tadayuki Takahashi , acommittee organizer and Principle
Investigator at Kavli IPMU, opened
this inaugural workshop. Addressing
an audience consisting of scientists
from the field of nuclear medicine ,chemistry, physics , engineering , andpharmaceutical sciences , Professor
Takahashi asked : how can we all
work together to help physicians
establish new treatment for advanced
cancers in order to boost cancer
survival rates?
Over the course of 2 days, 16 worldleading interdisciplinary scientists
presented their current and future
research activities to stimulate newideas. We heard from eminent medical
doctors about current state of affairs
in cancer treatment and research. For
instance, in Japan over 30% of cancer

30

patients have advanced cancer when
diagnosed, and only 14% of stage
IV cancer patients will survive after
five years using current technologies
and treatment.＊ With the objectiveof eradicating cancer at the cellularlevel, Professor Hideyuki Saya fromthe Division of Gene Regulation at
the Institute for Advanced Medical
Research at Keio University School of
Medicine discussed the need for new
methods and technologies which canbe used to distinguish between cancer
stem cells in order to eliminate boththe cancer stem cells themselves andtheir derivatives.
Particle accelerators play a crucialrole in cancer therapy and in theproduction of radio pharmaceuticals.
The Paul Scherrer Institute in
Switzerland use proton therapy
with remarkable success, treating
more than 7,000 patients with a98% cure rate, while in Japan, RCNP,
Osaka Univ. has started Astatine-211
production by cyclotron aiming
for new alpha-ray therapy. The
development of a new 100-milliondollar radio pharmaceutical facility
will be completed by 2023 at
TRIUMF in Canada for the purposeof developing advance rare isotope.
These movements will inevitably leadto the development of new detection

Kavli IPMU News No. 45 March 2019

systems.
A recurring theme during theWorkshop was highlighting thetransferrability of technology andmethods developed in high energy
physics experiments and in the fieldof astrophysics to the field of medicalimaging. The advancement andpresent limitations of fast detectors,
digital photon counting through tothe application of machine learningfor signal processing, data analysis andoptimized readout algorithms werediscussed.
Future development of high energy
resolution detectors and reaching
beyond the 100 micrometer scale, andvisualization of in vivo multiple drugdelivery system to boost survival rates
is underway at Kavli IPMU. Energy
resolution is essential for multi-probevisualization, and particularly forimaging the alpha-emitting cancer
therapy isotope Astatine-211 ofwhich there is active collaboration
between Kavli IPMU and the National
Cancer Center at Kashiwanoha, Japan
where experiments for detecting＊T. Matsuda et al., Research Group of
Population-Based Cancer Registries of Japan.
Population-based survival of cancer patientsdiagnosed between 1993 and 1999 in Japan:
a chronological and international comparative
study. Japanese Journal of Clinical Oncology
2011; 41: 40-51.

Astatine-211 are currently being
performed.
It will likely require new benchmarksof human ingenuity to overcome theunique hurdles facing cancer research.
An obvious catalyst for ingenuity is

to bring together interdisciplinary
researchers from across the World tocreate new and novel imaging devices
to detect the radio pharmaceuticals
and just as importantly to also
understand what we are seeing.

With that in mind, the organizing
committee is pleased to announce
that the INTERdisciplinary Approach
to Cancer Treatment (INTERACT) will
be held annually, with the next event
being held in France in 2020.

The participants of the inaugural workshop titled Interdisciplinary approach of applying cutting-edge technologies at the frontier of cancer research to discussurgent issues in modern cancer research and to report on the latest developments of cutting-edge technologies used for clinical applications.

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