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.

Working groups of between two and six
physicists are encouraged. Click here for more
information.

May
29 - June 19
Interplay of Fundamental Physics and
Machine Learning

Organizers: Ann Lee, Carnegie Mellon
University
Konstantin Matchev, University
of Florida
Harrison Prosper, Florida
State University
*Jesse Thaler, Massachusetts
Institute of Technology

The deep learning revolution has
demonstrated the power of AI to impact
society, including how physicists conduct
ground-breaking research. Deep
learning models and associated training
algorithms have found numerous
applications in fundamental physics,
especially in the analysis of data at
collider and neutrino experiments. Yet,
off-the-shelf AI tools are not always well
matched to physics applications. Not only
do physics data sets have special
structures and symmetries that must be
preserved, but most physics analyses
require stringent uncertainty estimation,
robustness, and verifiability that go
beyond what is currently available within
the standard deep learning toolkit.
Therefore, the time is ripe to fuse
advances in deep learning with the
time-tested strategies of “deep thinking”
in the physical sciences.

This workshop will bring together
theoretical physicists, experimental
physicists, AI practitioners, and
statisticians to discuss the dynamic
interplay of fundamental physics and
machine learning (ML). The workshop has
two complementary goals: (1) to identify
and promote the use of the newest ML
technologies to tackle some of the most
challenging problems in high-energy
physics, from precision calculations of
particle interactions to the extraction of
new physics from noisy data; and (2) to
advance AI more broadly through the
development of novel approaches that
incorporate first principles, best
practices, and domain knowledge from
fundamental physics. The workshop will
primarily focus on high-energy physics
topics. However, we note that similar
problems and challenges (e.g.,
verification and interpretability of ML
solutions) arise in the development and
deployment of ML methods in many related
fields.

May
29 - June 19
Large-Scale Structure Cosmology beyond
2-Point Statistics

Organizers: Donghui Jeong, Pennsylvania
State University
Elisabeth Krause, University
of Arizona
Hiranya Peiris, University
College London
*Fabian Schmidt, Max Planck
Institute for Astrophysics

Progress in cosmology has always been
characterized by a close interplay
between theoretical predictions and
observational data. This connection has
so far largely played out at the level
of simple summary statistics, such as
the two-point correlation function or
power spectrum. However, how do we
extract the substantial additional
cosmological information in statistics
beyond the power spectrum robustly and
efficiently? By bringing together
theorists, observers, and data
scientists, this workshop aims to make
progress on (i) determining the most
promising observables and probes; (ii)
identifying key challenges in mapping
theory to observables; (iii) making the
theory-data confrontation robust against
observational systematics. Concrete
collaboration during the course of the
workshop will be based on a data
challenge that will allow all
participants to test their theoretical
models and analysis/inference pipelines.

June 5 - July 3 Fundamental Physics and Astrophysics
with the Next Generation of
Gravitational-Wave Detectors

Organizers: Stephon Alexander, Brown
University
Vassiliki Kalogera, Northwestern
University
*Sanjay Reddy, University of
Washington
Bangalore Sathyaprakash, Pennsylvania
State University

The planned upgrades of current
gravitational-wave detectors and proposed
new observatories will enable precision
measurement of cosmological parameters,
observation of stochastic backgrounds from
the early universe, determination of
the properties of dense QCD matter,
heavy-element nucleosynthesis, precise
tests of the nature of gravitational
interactions, and a measurement of the
merger rate of compact binaries throughout
cosmic history. The new
observatories would benefit a wide range
of physicists, astrophysicists and
cosmologists but achieving their
scientific goals would require a
cross-disciplinary endeavor that would
benefit from extensive debate and careful
planning which is the chief goal of this
Aspen workshop.

Organizers: Sarah Marzen, Claremont
McKenna College
*Joshua Shaevitz, Princeton
University
Greg Stephens, Vrije
Universiteit Amsterdam & OIST Graduate
University Vincenzo Vitelli, University
of Chicago

This workshop will focus
on learning dynamical models and equations
from biophysical time series data across
systems. Recent advances in experimental
technologies to measure multidimensional
time series data from living systems (e.g.
the pose of an animal over time, the
relative fractions of different genotypes
in a population, the spread of COVID-19
variants worldwide, and the dynamics of
neurons in the brain) have led to an
explosion in the amount of data available
for analysis. In parallel, new techniques
in machine learning and artificial neural
networks have made great strides in
learning the underlying dynamical
structure and equations that govern these
kinds of time series. This workshop will
bring together experimentalists,
theorists, phenomenologists, computer
scientists, and engineers to highlight
recent advances and foster cross-area
progress

June
19 - July 17
Programmable Quantum Matter: Many-Body
Physics in the Era of Quantum Advantage

Organizers: Sarang Gopalakrishnan, City
University of New York
Adam Kaufman, University of
Colorado, JILA, NIST
Monika Schleier-Smith, Stanford
University
*Dan Stamper-Kurn, University
of California Berkeley

The study of quantum
mechanical systems containing many
interaction elements is nothing new: We’ve
been at it since the first application of
the new quantum theory to explain the
properties of materials. But what is
very new – a new opportunity and a new
challenge – is the ability to deeply
control, measure, and even feed back to
many-body systems that follow the laws of
quantum mechanics at large scales of
length, time, and complexity. There
is a new nexus between many-body quantum
science, materials science, quantum
feedback and control, full microscopy of
quantum systems, and, overarching, quantum
information science. At its core,
this nexus asks fundamental questions
regarding the relationship between the
microscopic and macroscopic properties of
a quantum many-body system both in and out
of equilibrium, and the role of the
dimensionality, environment, and
interactions in realizing emergent
properties. The proposed summer program at
the Aspen Center for Physics will focus on
this nexus, drawing together known experts
and rising stars, experimentalists and
theorists, from a broad range of
disciplines within physics and also
beyond.

Organizers: *Jason Dexter, University
of Colorado Boulder
**Daryl Haggard, McGill
University
Feryal Ozel, University of
Arizona
*David Radice, Pennsylvania
State University Lorenzo Sironi, Columbia
University

The past few years have
brought about remarkable progress in
physics of plasmas around black holes and
neutron stars from many directions.
Interferometric techniques with the Event
Horizon Telescope and GRAVITY have led to
high-resolution near-horizon images of
black holes, while LIGO has observed two
neutron star mergers. In parallel, NASA’s
Parker Solar Probe has been collecting
data in the immediate vicinity of the sun,
providing highly pertinent data on
particle heating and instabilities in
rarefied, highly magnetized plasmas. The
pace of fluid- and kinetic-based studies
of the plasma in accretion disks and in
dynamical general relativistic spacetimes
has dramatically increased, providing
simulations with better inertial range and
more predictive results. Our proposed
workshop builds on these exciting recent
developments for understanding plasmas
around compact objects and looks further
ahead to bringing diverse plasma, gravity,
solar physics, and compact object
astrophysics communities together to build
theoretical and observational foundations
of future directions. The participants in
the workshop will focus on new techniques
for modeling astrophysical plasmas around
compact objects including ideal and
non-ideal magnetohydrodynamics (MHD),
particle-in-cell (PIC), and other
computational techniques for the flows
around single and binary compact objects,
exploration of instabilities at small
scales, inputs for particle heating and
acceleration from the Parker Solar Probe,
observational implications for EHT,
multiwavelength observations, and
counterparts of neutron star mergers.

July
31 - August 21
Novel States of Matter and Topological
Particles in Bulk Quantum Materials

Organizers: Efrat Shimshoni, Bar-Ilan
University
Chandra M. Varma, University of
California Riverside
Ashvin Vishwanath, Harvard
University
*Amir Yacoby, Harvard University

The aim of the workshop is to bring
together, to the unique atmosphere and
manner of operation of the Aspen Center
for Physics, the prominent experimental
and theoretical leaders together with a
new generation of theorists and
experimentalists to discuss and evaluate
the most important experimental
discoveries and theories in quantum
condensed matter developed in the last few
years. Among the topics to be covered are
manifestations of novel electronic phases,
including topological and chiral
superconductivity, correlated Chern
insulators, spin-liquids, new species of
fractional quantum Hall states,
magneto-oscillatory phenomena in
correlated insulators, and new states far
from thermal equilibrium. The experimental
advances in these frontiers have been
enabled by new fabrication and
characterization techniques. Powerful
numerical techniques together with
controlled analytical solution of simple
models pertinent to the problems posed by
the experiments have only offered a
glimmer of the new physical principles
demanded by the experiments. The workshop
will help set the directions for further
experimental and theoretical discoveries
towards their elucidation.

August 7 - 28
Effective Field Theories: From Quarks to
the Cosmos

Organizers: *Timothy Cohen, University of Oregon
Nathaniel Craig, University of
California Santa Barbara
Yael Shadmi, Technion-Israel
Institute of Technology
Zhengkang Zhang, California Institute
of Technology

Although EFT techniques
are by now ubiquitous in physics,
something of an EFT renaissance has been
occurring within high-energy physics in
recent years, driven on the one hand by
the development of new theoretical
techniques, and on the other hand by the
growing sensitivity of experiments at the
energy, intensity, and cosmic frontiers.
Measurements at the LHC, DUNE, BELLE-II,
LIGO, EIC, Muon g-2, Simons Observatory,
and diverse dark matter detectors -- not
to mention a host of planned or proposed
experiments -- will both benefit from this
ongoing progress and motivate further
advances. This workshop will bring
together EFT experts working across the
spectrum of high-energy physics to
cross-pollinate new theoretical
developments; connect EFT frameworks at
their interfaces; and strengthen the
dialogue with experimental collaborations
using EFT tools in their analyses. We aim
to cover a wide spectrum of applications,
including EFTs for the Higgs (and LHC
analyses more broadly); dark matter
searches; flavor and neutrino physics;
inflation and large-scale structure;
gravitational waves; and classical or
quantum simulation of field theories. The
workshop will also highlight and
facilitate progress in broadly applicable
tools for EFT.

Organizers: *Veronika Hubeny, University of
California Davis
Mukund Rangamani, University of
California Davis
Stephen Shenker, Stanford
University
Mark Van Raamsdonk, University of
British Columbia

Gauge/gravity
duality has taught us many interesting
lessons about the dynamics of strongly
coupled systems, and has provided us with
many insights into the workings of quantum
gravity. Despite this remarkable
progress much remains to be done,
especially in understanding deep
conceptual questions that underpin a
non-perturbative theory of quantum
gravity. In recent years we have
come to appreciate that the key to
unlocking some of these secrets may lie in
connections to quantum information
theoretic concepts. Some of these ideas
have been made quite sharp in more
tractable low-dimensional settings, e.g.,
in the SYK model and its gravitational
dual -- 2D dilaton gravity. The aim
of the workshop is to facilitate further
progress in these directions. We
anticipate particular focus on questions
such as: the emergence of semiclassical
spacetime geometry; the Page curve,
islands and replica wormholes; the nature
of black hole microstates; the link
between disorder averaged quantum dynamics
and gravity; and others that will
certainly arise in this rapidly developing
field.

August 21 - September
18 Random Geometry in
Statistical Physics, Condensed Matter,
and Quantum Gravity

Organizers: Alexander Altland, University
of Cologne
Nele Callebaut, University of
Cologne
*Matthew S. Foster, Rice
University
Ilya Gruzberg, Ohio State
University

The statistical physics
of random geometric structures is a rich
source of physical phenomena. Recent
manifestations include:

holographic interpretations of
random systems such as the SYK model,

measurement-driven transitions in
random quantum circuits, and

geometric views of many-body quantum
chaos.

The common feature of all
these and numerous other statistical
phenomena is that randomness manifests
itself through geometric structures.
Recent methodological advances driving
these developments include novel matrix
approaches to quantum gravity, random
tensor networks, TTbar-deformed 2D quantum
field theories, and the probabilistic
formulation of fractal geometry. This
workshop will bring together researchers
from the statistical physics, condensed
matter, and quantum gravity communities.
The recent history of the SYK model has
set an example for how randomness has the
potential for unification across the
boundaries of these fields. Yet the
applications and methodological
innovations sketched above indicate a far
wider vista for further collaboration and
development. Topics of particular mutual
interest that will be addressed at this
workshop include

SYK physics,

TTbar theory,

Liouville CFT, log-correlated random
energy models, the Knizhnik, Polyakov,
and Zamolodchikov formula, and

the structure and applications of
logarithmic CFTs.

Organizers: Vincenzo Cirigliano, Los
Alamos National Laboratory
Andreas Crivellin, CERN
*Stefania Gori, University of
California Santa Cruz
Martin Hoferichter, University
of Bern

In the past several years, various
measurements at low and high energy
colliders revealed intriguing hints for
physics beyond the Standard Model. This
includes flavor anomalies in B-decays,
beta decays, the g-2 anomaly, and several
LHC measurements. The energy scale
associated with these anomalies spans a
very wide range, from the nuclear scale to
the multi-TeV scale. This motivates new
phenomenological and theoretical
investigations, and new searches at a wide
range of accelerator experiments: the LHC,
flavor and nuclear physics experiments, as
well as fixed-target experiments. In this
workshop, we aim at bringing together
scientists working on nuclear, flavor,
LHC, and dark matter/dark sector physics
to investigate the complementary probes of
New Physics motivated by the current
anomalies in data. Recent developments in
theoretical calculations (e.g., g - 2)
will also be scrutinized. The common goal
is to use probes at vastly different
energy regimes, from nuclear to LHC scales
and even beyond to future colliders, to
unveil physics beyond the Standard Model.

Organizers: Clay Cordova, University
of Chicago
*Julia Plavnik, Indiana
University
Sakura Schafer-Nameki, University
of Oxford
Constantin Teleman, University
of California Berkeley

Systematic understanding
of phases of matter is a fundamental
problem. Furthered by their
characterization in terms of topological
QFTs (TQFTs) --- the presumptive
low-energy regime of gapped QFTs --- the
coupling of phases to global topological
symmetries is the focus of much ongoing
research. This (condensed matter) physics
also interfaces with high energy physics,
for instance in the infrared behavior of
gauge theories in low dimension. On the
condensed matter side, gauge symmetries
are often emergent degrees of freedom in
the short lattice spacing. On the
high-energy side, the infrared structure
of strongly coupled QFTs is notoriously
difficult to determine; new advances are
needed in studying their dynamics.

Symmetries and anomalies
are among the few universally applicable
tools, and developing them is a priority
for both fields. A new path for their
mathematical study was opened by Lurie's
"cobordism hypothesis'" description of
TQFTs, leading to the effective use of
higher category techniques. Still, certain
examples (anyons, Levin-Wen models), as
well as classification work on boundary
theories, show the need for
generalizations of the cobordism
hypothesis (with embedded defects) as an
organizing principle and indicate that the
full power of these methods is yet to be
exploited.

We plan to bring
together experts in condensed matter,
quantum field theory and topology to forge
new advances at the interface of these
subjects, with mutually reinforcing ideas
from physics and mathematics in vigorous
exchange and contraposition as part of an
intense workshop.