2013 SUMMER
PROGRAM
* denotes the organizer
responsible for participant diversity in
the workshop
May 26 – September
15
Individual Research
Physicists are encouraged
to apply as individual researchers to work
on their own projects for up to five weeks
at any time during the summer. We provide
a serene atmosphere to complete work. The
individual researcher may also choose to
attend any workshop meetings or chat with
other scientists in residence in addition
to working on his or her own research.
Click here for more
information.
May
26 – September 15
Working Group
Working groups of between two and six
physicists are encouraged. Click here for more
information.
May 26 - June 30
Physics of Functional
Biological Assemblies: Pushing, Pulling
and Sensing
Organizers:
Ajay Gopinathan, University
of California, Merced
Fred MacKintosh, Vrije
University
Jennifer Ross*, University
of Massachusetts
David Sept, Washington
University
Biology provides many
rich examples of complex and adaptive
materials. Cellular systems, in
particular, pose fundamental challenges
that arise from their non-equilibrium
nature and their hierarchical structures.
Cytoskeletal filaments, for example, that
occur in conjunction with motors and
associated proteins are extremely
versatile and can display a wide range of
dynamically self-assembled structures
including radially organized filaments,
bundles, cross-linked networks, networks
of bundles, membrane associated two
dimensional networks and even liquid
crystalline phases depending on context
and function. Cytoskeletal assemblies
govern spatial organization within the
cell, the production and transmission of
forces, serving as physical and chemical
links to the external world and serving as
a network for intracellular transport.
Function in this system emerges from the
interplay between the mechanical
properties, dynamics, interactions and
biochemical regulation of the constituent
elements – providing a fertile ground for
applying physical principles to
biologically relevant problems and for
uncovering new unanticipated physics in
these active, dynamic and functional
materials.
While we have learnt a significant amount
about the physics of these systems, the
next hurdle is to relate this more closely
to cellular function. We believe the time
is ripe to address this challenge by
hosting a workshop that can bring together
theoretical physicists, experimental
biophysicists and cell biologists. This
will enable the identification of current
theoretical and computational challenges,
as well as key questions that need to be
addressed by quantitative, physics-based
experiments. A five-week workshop focusing
on the physical basis of function in these
remarkable assemblies should therefore
provide a foundation for innovative new
cross-disciplinary approaches.
May 26
- June 16
Lattice Gauge Theory
in the LHC Era
Organizers:
Simon Catterall,
University of Syracuse
Paul Damgaard, Niels
Bohr Institute
Anna Hasenfratz*,
University of Colorado
Yannick Meurice, University
of Iowa
The goal of the workshop
is to bring together lattice gauge
theorists involved in the study of various
non-perturbative aspects of what is called
Physics Beyond the Standard Model. These
include alternatives or modifications of
the standard Higgs mechanism,
supersymmetry, and electroweak precision
tests, all of which require
non-perturbative lattice studies. Beyond
Standard Model investigations are a major
program at the Large Hadron Collider
(LHC), and given the timeline for the
experimental effort at the LHC, this
workshop is very timely. There are two
principal ways to search for Physics
Beyond the Standard Model; direct
exploration and indirect searches for
signals via precision calculations of
observables in the Standard Model. In the
former case, lattice gauge theorists have
in recent years established programs to
study candidate both composite Higgs
theories such as technicolor and also
supersymmetric gauge theories. In the
latter case, there is a well established
program in the lattice gauge theory
community to provide precision
calculations of strong interaction effects
in weak matrix elements. By comparison
with experiment such calculations can
yield signs of Beyond Standard Model
Physics.
May
26 - June 16
The Origins of
Stellar Clustering: From Fragmenting
Clouds to the Build-Up of Galaxies
Organizers:
Nate Bastian, Excellence
Cluster Universe
Diederik Kruijssen*, Max
Planck Institute for Astrophysics
Mark Krumholz, University
of California, Santa Cruz
Steve Longmore, European
Southern Observatory
Some fraction of all
stars is formed in gravitationally bound
stellar clusters, while the remainder
originates in unbound associations. It is
not understood which physical mechanisms
generate either result. Recent work
indicates that the outcome of the
star/cluster formation process may already
be set by the characteristics of the
interstellar medium at the onset of
gravitational collapse. If true, this
provides a promising ansatz to identify
the physics of cluster formation: the
conversion of gas into stellar clusters.
With the new generation of observational
facilities such as Herschel, ALMA, Gaia,
and JWST, it will be possible to follow
the time evolution of the entire star
formation process, from the structure of
the interstellar medium and the initial
collapse of giant molecular clouds to the
emergence of massive, dense stellar
clusters. The insights that will follow
from these observations can be interpreted
in the context of galaxy formation and
evolution, allowing an understanding of
how the galaxy-scale environment and
small-scale star formation events are
influenced by each other.
By bringing together experts in the theory
and observations of the physics of the
interstellar medium, star/cluster
formation, cluster populations, and star
cluster/galaxy evolution, this workshop is
intended to make significant progress in
understanding the wide range of scales and
mechanisms that govern the star and
cluster formation process. The three weeks
of the workshop will include the following
themes. Throughout, there will be a
natural focus on how to direct the theory,
numerical work, and observations to meet
on common grounds.
1) The current theoretical understanding
of star and cluster formation
- How do collapsing giant molecular clouds
(GMCs) fragment and convert their gas into
stars?
- Which feedback mechanisms halt star
formation, and how does the resulting gas
expulsion affect the formation of stellar
clusters?
- How do the global characteristics of
galaxies influence the properties of GMCs
and clustered star formation?
2) Observational constraints on star and
cluster formation
- How well can the progenitors of stellar
clusters currently be identified in the
interstellar medium (ISM)?
- Which observational methods can be used
to determine the gravitational boundedness
of young stellar structure?
- What do galaxies other than the Milky
Way tell us about the variation of stellar
clustering with the galactic environment?
3) Connecting the dots: towards an
understanding of stellar clustering
- Where do the small-scale and
galaxy-scale physics of star formation
meet and how should both be combined in a
complete picture of cluster formation?
- How will the recent and upcoming
observational facilities enable us to
constrain the physics of cluster
formation?
- How can we address the variation of
stellar clustering with cosmic time?
- What can we learn about globular cluster
formation by considering star and cluster
formation in the nearby universe?
May 26
- June 16
The Obscured
Universe: Dust and Gas in Distant
Starburst Galaxies
Organizers:
Andrew Benson, Carnegie
Observatories
Caitlin Casey, University
of Hawaii
Asantha Cooray*,
University of California, Irvine
Olivier Dore, Jet
Propulsion Laboratory
Alexandra Pope, University
of Massachusetts
Dominik Riechers, Caltech
The goal of this workshop is to bring
together observers, theorists, and
experimentalists who study the cosmic
infrared background and the associated
dusty starburst galaxies in the universe
from today to the epoch of reionization.
Existing facilities such as the Herschel,
ALMA, and ground-based instruments and
interferometers have now discovered large
samples of dusty galaxies and are starting
to probe their physical details with
multi-wavelength data. These facilities
have begun to provide detailed
observations related to gas, dust and
stars of galaxies during their peak
activity which can be used to improve
existing theoretical models of dusty star
formation. Future facilities such as CCAT
and LMT will make further improvements in
our understanding of the universe at
sub-mm wavelengths. Existing studies with
Planck, SPT and ACT suggest that these
dusty galaxies generate an important
secondary CMB anisotropy signal and its
characterization would be crucial for a
variety of CMB studies. The preliminary
Herschel results show that sub-mm surveys
can identify large samples of lensed
sub-mm galaxies with efficiency close to
100% - thereby providing a wealth of
cosmological information.
A summary of topics to be discussed during
the workshop follows:
* Sub-mm galaxy properties: dust
production, the initial mass function of
the stars, AGN activity, gas-rich mergers
vs. cold flow accretion, gas consumption,
the trigger and shut-off mechanisms that
form and destroy the starburst phenomenon
in galaxies, connection between
theoretical models.
* Sub-mm survey statistics: sub-mm surveys
from Herschel to CMB experiments,
clustering, lensing, first SMGs in the
universe at z~6, redshift distribution,
multi-wavelength properties of sub-mm
galaxies;
* Future: planned surveys and instruments,
novel measurement techniques at sub-mm
wavelengths from space and beyond.
June
16 - July 7
The Next Decade of
Weak Lensing Science
Organizers:
Bhuvnesh Jain,
University of Pennsylvania
Alexie Leauthaud, Kavli
Institute for the Physics and Mathematics
of the Universe
Rachel Mandelbaum*, Carnegie
Mellon University
Ludo van Waerbeke,
University of British Columbia
The scientific promise of weak gravitational
lensing (WL) has inspired a number of very
ambitious observational programs starting in
2012/2013 (KIDS, Pan-STARRS, HSC, DES), and
several more to begin in about a decade from
now (LSST, Euclid). These surveys will cover
an order of magnitude more sky area than
most existing ones (thousands of square
degrees of sky rather than hundreds), and
due to the greater statistical power, better
control of systematic errors is also
required. The WL community therefore must
learn as much as possible from existing data
in order to focus its efforts for the next
generation surveys, both to reduce the main
sources of systematic error and to develop
more sophisticated ways of handling
outstanding theoretical issues.
In the past few years, there has been
extensive development in WL theory,
observations, and numerical simulations. The
field of WL now reaches such a maturity and
level of complexity that future surveys will
benefit considerably from tighter
connections between the different areas. We
envision a workshop that will establish
strong and durable connection between
observers who focused on the previous
generation of lensing surveys, those working
on the next generation, and theorists. The
ultimate goal is to guide the efforts of
those working on the next generation
surveys, which will include thorough
discussion of ways to minimize and
characterize systematic errors (through
hardware, software, and careful survey
design) that plagued previous surveys, and
development of theoretical techniques to get
the most information from the data while
minimizing sensitivity to any residual
systematics.
Among the observational systematics under
discussion will be robust measurement of
galaxy shapes under realistic imaging
conditions; and estimation of photometric
redshifts (line-of-sight distances to
galaxies using broad-band photometry) to get
redshift estimates for all galaxies, and the
use of spectroscopic surveys for calibration
purposes.
Another equally important aspect is data
reduction of very large data sets and data
mining, more specifically what future
surveys can learn from computer science
techniques and high energy physics to deal
with the ever increasing data flow.
Among the theoretical topics of discussion
are intrinsic alignments of galaxy shapes
(due to, e.g. local tidal fields - which can
mimic a lensing signal); optimal ways to
distinguish between dark energy and
modifications of the theory of gravity; and
minimization of theoretical uncertainties in
the observables, e.g. due to the (currently)
poorly known effects of baryons (luminous
matter).
Regarding numerical simulations, the topics
of discussion will include the important
question of small-scale modeling of the dark
matter power spectrum and its sensitivity to
baryonic physics such as AGN, supernovae
winds and other feedback mechanisms.
The workshop will allow a significant amount
of time for informal discussions and the
development of new research collaborations.
June
16 - July 21
Disorder, Dynamics,
Frustration and Topology in Quantum
Condensed Matter
Organizers:
Cristian Batista, Los
Alamos National Laboratory
Joel Moore, University of
California, Berkeley
Gil Refael*, Caltech
Nandini Trivedi, Ohio
State University
Ali Yazdani, Princeton
Taken independently, disorder leads to
quantum interference and localization,
interactions to Mott and Wigner insulators,
and spin-orbit coupling to topological band
insulators. What is the result, however, of
combining topology with interactions and
disorder? What is the nature of new states
of matter induced by topology in interacting
systems and the quantum phase transitions
between them? How do disorder effects, such
as localization, modify dynamics in
interacting systems, and to what extent does
topological protection still apply?
Similarly, the effects of disorder and
defects is far from clear in frustrated
interacting quantum systems, which give rise
to exotic phases such as spin-liquids, or
Fermi-liquid with incommensurate order. The
aim of the workshop will be to foster
discussion of the ideas, experiments and
techniques that could help us overcome these
broad challenges.
July
7 - August 4
Mathematics of
Superconformal Field Theory
Organizers:
Daniel Freed,
University of Texas
Gregory Moore, Rutgers
University
Andrew Neitzke,
University of Texas
Hirosi Ooguri*, Caltech
Superconformal field theory is a topic of
current significant activity in both the
math and physics communities. This workshop
has two focal points: the
(2,0)-superconformal field theory in six
dimensions and the scattering amplitudes of
N=4 super Yang-Mills theory in four
dimensions. These two subjects have been the
loci of dramatic developments in the last
few years. Moreover, there are tantalizing
indications that they are actually linked.
Very few interacting quantum field theories
are known in dimensions greater than four.
Doubtless the most fascinating of these is
the (2,0)-superconformal field theory in six
dimensions, first conjectured to exist in
1995 based on string theory arguments. The
mere existence of the (2,0)-theory has
fantastic consequences for more familiar,
lower-dimensional theories. There are deep
connections to pure mathematics as well.
Despite the remarkable applications of the
existence of the six-dimensional
superconformal theories, there is no
systematic construction of these theories
from first principles, not even at a
physicist's level of mathematical rigor.
Several different approaches have been
suggested, but none has been entirely
successful. One goal of the workshop is to
bring together people working on these
different approaches to the foundation of
the subject. In particular, recent advances
in the mathematical structure of topological
and conformal field theory are likely to
play an important role in this endeavor.
N=4 super Yang-Mills is the most
supersymmetric quantum field theory in four
dimensions. Textbook methods for studying
the theory make it look forbiddingly
complex, but recently there is evidence from
many different perspectives that the theory
has a deeper underlying integrability. This
integrability is visible even in the most
basic quantities derived from the theory:
scattering amplitudes. The traditional
procedure at weak coupling via Feynman
integrals is forbiddingly laborious.
Powerful new methods for computing these
amplitudes both at weak and strong coupling
have been developed over the last few years,
combining ideas from all over the map:
twistors, Yangian symmetry, holography,
multidimensional residue calculus, number
theory, and cluster algebras. These methods
have vastly expanded the horizon of what can
be computed. The answers, moreover, turn out
to be simpler than they have any real right
to be. This points to new fundamental
organizing principles---perhaps for quantum
field theory in general---an enticing
possibility to be explored in the workshop.
Some of the new mathematical tools used in
the computation of perturbative amplitudes,
most notably cluster algebras and cluster
varieties, have also found prominent
applications in investigations of the new
superconformal field theories mentioned in
the previous section. This suggests that
there are further deep relations between the
new insights in (2,0)-theories and the new
methods in computing perturbative
amplitudes.
July
21 - August 11
The Milky Way as a
Laboratory for Galaxy Formation
Organizers:
Kathryn Johnston*, Columbia
University
Andrey Kravtsov,
University of Chicago
Constance Rockosi, UCO/Lick
Observatory
Monica Valluri,
University of Michigan
Mark Wilkinson,
University of Leicester
Formation of luminous
stellar components of galaxies within the
context of hierarchical structure
formation remains one of the main unsolved
problems in astrophysics today.
This workshop will bring together
observers, simulators, modelers and
theorists to focus on how current and
future resolved star surveys of the Milky
Way can be used to reconstruct the
structure and formation history of the
Galaxy in a cosmological context. The
questions addressed at this workshop will
include
(a) How can detailed stellar dynamical
modeling be used to estimate the density
of dark matter in the vicinity of the Sun
(influencing direct dark matter detection
experiments on Earth), as well as the
global shape and density distribution of
Galactic dark matter?
(b) How can the distributions of the
kinematics, ages and abundances of halo
stars be used to infer the formation
history and structure of the stellar
halo(s) and Galactic disk(s)?
(c) What does the satellite system of the
Milky Way tell us about the extreme edge
of galaxy formation?
(d) How have the evolution of the bulge,
bar, disk and halo of our Galaxy altered
their individual properties and the
relationship between them, and how can our
understanding of their co-evolution inform
our understanding of the formation and
evolution of galaxies from high redshifts
to today? A significant goal of this
workshop is to identify the modeling and
simulation tools that need to be developed
to construct dynamical and stellar
population models of our Galaxy and its
various components from the enormous
datasets that will soon be available from
surveys such as APOGEE, LAMOST, Hermes,
Gaia and LSST.
August
4 - August 25
Optical Lattice
Emulators and Beyond
Organizers:
Nigel Cooper,
University of Cambridge
Tilman Esslinger, Swiss
Federal Institute of Technology
Jason Ho*, Ohio State
University
Matthias Troyer, ETH
Zurich
The development of optical lattice
emulators is among the most ambitious
projects ever conducted in atomic physics
research. The goal is to use cold atoms in
optical lattices to simulate important
lattice models in condensed matter physics
whose solutions remain unknown so far. In
the last few years, there have many
significant advances in this effort
including "quantum simulations" of the
bosonic and fermionic Hubbard models and
imaging of atoms in optical lattices. The
recent success in producing synthetic
gauge fields heralds a new generation of
cold atom experiments to study spin-orbit
effects for bosons and fermions including
all those in solids. In addition, recent
successes in cooling rare earth atoms and
dipolar molecules to quantum degeneracy
provide new classes of systems with
extraordinary high symmetry (like SU(N))
systems, as well as with long range
interaction. Theoretical studies of cold
atoms in optical lattices have also
continued to blossom in the last few
years. There is an increasing number of
studies of new phases in optical lattices.
At the same time, numerical techniques
have risen to a new height to tackle many
optical lattice problems. This flurry of
excitement in both theory and experiment
is a reflection of the great ambitions of
the field: to realize the most novel
systems in condensed matter and to create
new forms of quantum matter difficult to
achieve in solids; to explore new
mechanisms for strong interaction and
strong correlation (hence superfluids with
high Tc/TF) ratio; to realize and to
manipulate topologically protected
excitations; to manufacture, and to find
applications of highly entangled quantum
states. This workshop aims to bring
together theoreticians and
experimentalists to push forward the
frontier of this exciting field.
August
11 - September 1
Implications of LHC
Higgs-Like Signals
Organizers:
John Gunion, University
of California, Davis
Howard Haber,
University of California, Santa Cruz
Andrey Korytov,
University of Florida
Laura Reina*, Florida
State University
In July 2012, the ATLAS and CMS
collaborations announced the discovery of
a new boson with properties suggestive of
the Higgs boson of the Standard Model
(SM). Since then, additional LHC running
has increased the integrated luminosity by
nearly a factor of three. With this
substantially larger Higgs data sample,
the new analyses of the ATLAS and CMS
collaborations are beginning to provide a
comprehensive picture of the production
and decay properties of the 125 GeV
Higgs-like state in a variety of channels.
Using this data, one will be able to start
to differentiate among models of
electroweak symmetry breaking. The Higgs
signal could converge towards the SM
expectations in all production and decay
channels or exhibit significant
deviations. In the atter case, models that
incorporate new physics beyond the SM
(BSM) will be examined for consistency
with the data. The Higgs signal has
profound implications for supersymmetric
models, Randall-Sundrum models (with
Higgs-radion mixing), technicolor models,
little Higgs models, composite Higgs
models, non-minimal Higgs sectors and so
on. If there are still no direct signals
of new BSM physics at the LHC, then the
Higgs data and its interpretation will
dominate theoretical model building for
years to come. Of course, if the LHC
discovers additional new particles and
interactions beyond the SM, these
discoveries combined with the precision
measurements of Higgs properties will
significantly constrain models of BSM
physics.
The purpose of this workshop is to
summarize the experimental situation as of
the summer of 2013 and to explore the
implications of the Higgs data for the SM
and for models containing one or more
Higgs-like scalar particles. A key
ingredient of the Higgs studies will be
the improvement of the accuracy of the
theoretical predictions that are crucial
for the extraction of the Higgs boson
properties from the data.
August
18 - September 15
Dark Matter in
Galaxies, the LHC and Direct and
Indirect Searches: Are We Near the End
of the Road?
Organizers:
Marcela Carena, Fermi
National Laboratory
Carlos Frenk, Durham
University
Graciela Gelmini*,
University of California, Los Angeles
Jennifer Siegal-Gaskins,
Caltech
Identifying the nature of the dark matter
(DM) is one of the most fascinating and
important problems in contemporary
physics, and one whose solution may well
be within reach. The LHC is exploring many
models of new physics that could explain
the DM, as well as the direct production
of DM. Direct DM searches have provided us
with plenty of excitement related to
’Light WIMPs,‘ and this issue will see
further developments soon. Tantalizing
hints of DM signals have also appeared in
indirect searches, such as a 130 GeV line
in Fermi LAT data and the rise in the
cosmic-ray positron fraction measured by
PAMELA and Fermi LAT. Moreover, gamma-ray
limits are, for the first time, excluding
regions of parameter space for canonical
thermal relic WIMP DM. Recent kinematical
data for the dwarf galaxy satellites of
the Milky Way combined with rigorous
predictions of the properties of these
systems done with a new generation of
ultra-high-resolution N-body simulations,
have lead to conflicting evidence: some
studies imply that not all is well with
the standard Lambda-CDM model and that
warm, rather than cold, DM provides a
better match to the dwarf satellite data,
others, however, suggest that baryon
effects can change the picture in subtle
but important ways.
This workshop will bring together particle
physicists and cosmologists specializing
in the issues most relevant for DM
detection, including the DM distribution
in galaxies as well as all current
collider, direct, and indirect searches
for particle DM, to explore the
complementarity of DM search strategies
and re-evaluate the observational evidence
for and against a variety of proposed DM
candidates.
August
25 - September 15
Multi-Component
Many-Body Systems
Organizers:
Egor Babaev*,
University of Massachusetts
Leo Radzihovsky,
University of Colorado
James Sauls,
Northwestern University
Asle Sudbo, Norwegian
University of Science and Technology
Research on the multicomponent systems has
increased enormously in recent years due to
a number of experimental breakthroughs.
These include unconventional and multiband
superconductors, topological superfluids and
superconductors, spinor Bose-Einstein
condensates, quantum mixtures of fermionic
and bosonic cold atoms, quantum magnets and
spin-liquids, and quantum Hall systems, and
various multicomponent gauge theories
emerging as effective theories in various
physical context. Multicomponent ordered
states often exhibit properties which have
no counterpart in single-component systems.
Despite a diverse range of microscopic
origins, at low energies this broad array of
systems can often be described by emergent
many-body theories exhibiting a significant
degree of universality. There are for
instance important connections between
topological insulators, quantum Hall physics
and the phases of superfluid 3He as well
multi-component cold atomic condensates.
This workshop will provide a forum for
many-body experts in a broad range of areas
to interact and exchange ideas on such
diverse multi-component systems.
September
1 - September 15
Astrophysical
Mechanisms of Particle Acceleration and
Escape from the Accelerators
Organizers:
Mikhail Malkov*,
University of California, San Diego
Patrick Diamond,
University of California, San Diego
Roald Sagdeev,
University of Maryland
Recent progress in observations brings high
energy astrophysics to the forefront of
particle physics experiments studying
fundamental laws. Cosmic rays (CR), with an
energy spectrum extended to 100 EeV, are
unique messengers with which to probe the
structure and evolution of the universe,
dark matter, neutrinos, and other important
phenomena in astroparticle physics and
cosmology, possibly including particles that
are yet to be discovered. The newest
discovery of the GZK feature at 30 EeV in
the CR spectrum bolsters our basic
understanding of how the universe works at
extreme energies but the observations also
pose new questions about the composition and
anisotropy of the spectrum. The workshop
will encompass CR acceleration mechanisms in
various astrophysical settings and discuss
their radiative and morphological
signatures. For more than thirty-five years
the diffusive shock acceleration (DSA, aka
Fermi-I) mechanism has been successfully
applied to CR production in supernova
remnants, gamma ray bursts, active galactic
nuclei, and even in the cosmic structure
formation shocks. However, its role in other
important phenomena such as magnetic field
generation, particle escape from
accelerators, their subsequent propagation
and interaction with ambient medium are not
fully understood. It is this interaction
that results in the emission that it is now
measured with unprecedented precision. These
measurements are not always explicable
within the standard DSA theory. Therefore,
alternative mechanisms, powered by magnetic
and turbulence energy, rather than by the
mechanical shock energy, will also be
discussed.
