* denotes the organizer responsible for participant diversity
** denotes a scientific advisor

Click Here to View the Summer Poster

May 30 - September 19
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 30 - September 19
Working Group

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

May 30 - June 13
Transport and Mixing of Tracers in Geophysics and Astrophysics

Ryan Abernathy, Columbia University
Paul Kushner, University of Toronto
Albion Lawrence, Brandeis University
*Heloise Meheut, CRNS, Observatoire de la Cote d'Azur

The transport and mixing of tracers and particulates by fluids is a highly complex, multiscale problem that is central to many key questions in geophysics and astrophysics. As examples: dust and precipitation are key to the formation, structure, and evolution of the earth and planetary systems, as well as stellar environments; pollutants and reacting chemicals  in the atmosphere and oceans are important for local and global environments; and biological tracers such as phytoplankton play complex roles in the carbon cycle, a key climatic process. Furthermore, tracers provide a Lagrangian description of fluid flow that lend significant theoretical and observational insights into the circulation of the atmosphere and oceans. This workshop aims to bring together the earth science, astrophysics, theoretical physics, and applied mathematics communities to develop techniques for studying transport and mixing in both geophysical and astrophysical contexts.

May 30 - June 20
Galactic Archaeology with Fundamental Stellar Parameters: Synthesizing the Power of Accurate Ages with Distances, Chemistry, and Kinematics

Kathryne Daniel, Bryn Mawr College
Keith Hawkins, University of Texas at Austin
**Sarah Loebman,
University of California Davis
Marc Pinsonneault, Ohio State University
*Justin Read, University of Surrey

The Gaia satellite mission has revealed that the Milky Way’s (MW) stellar disk is in a complex, disequilibrium state.  Stellar chemistry can be used to reconstruct the evolution and formation of our Galaxy, but true Galactic Archaeology requires accurate stellar ages for individual stars that, for large statistical samples, have only recently become attainable.  With new, state-of-the-art data from the Kepler, K2, and Transiting Exoplanet Survey Satellite (TESS) missions now available, we have entered a golden age for precision stellar age determination. By combining the phase space positions of stars from Gaia with accurate ages for individual stars, we will be able to dissect our Galaxy in unprecedented detail. To fully realize the promise of these new data we must bring together expertise in time domain astronomy, astrometry, stellar evolution, galactic dynamics, galaxy formation and cosmology.  Focal themes for this workshop will include:

  • Applications of mapping 6D phase space, chemistry and ages of individual MW stars for understanding galaxy evolution
  • The power and limitations of time-domain astronomy for accurate stellar age determination through stellar rotation and asteroseismology
  • Chemo-dynamical evolution of MW-like galaxies
  • Tests of the standard cosmological model and constraints on the nature of dark matter.

June 6 - 27
Biology, Biophysics and Epidemiology of COVID-19 and other Pandemics

Gyan Bhanot, Rutgers University
Michael Biehl, University of Groningen
Charles De Lisi, Boston University
Sebastian Doniach, Stanford University

We are in the midst of a pandemic caused by the Sars-Cov-2 virus, which first appeared in Wuhan, China in December 2019 and has since spread around the world, igniting a global pandemic, and causing worldwide suffering and death. The disease caused by this virus, called Covid-19, ranges in severity from asymptomatic infection to flu-like symptoms, to viral pneumonia, to acute respiratory distress syndrome (ARDS), and sometimes, to death.  There has been a worldwide response from biologists, chemists, biophysicists, virologists, epidemiologists, and medical researchers to understand the dynamics and epidemiology of  transmission, disease progression,  the immune response from infection, and the wide variation in disease severity. There is also a great deal of work being done to find optimum treatments for patients, particularly those with severe disease, to find ways to control the spread of the virus, and to develop an effective vaccine. The workshop will include leading researchers from all these areas. The hope is that by bringing together experts from these diverse communities, there will be an exchange of ideas about the current pandemic, a discussion of lessons learned from past pandemics and discussions of how to deal with future pandemics. The workshop will also provide a platform for biophysicists working on this pandemic to interact with the wider community of researchers studying this and other pandemics, with the goal of fostering collaborations. We have begun to create a forum for discussions on this topic via a webinar series sponsored by the American Physical Society. Please visit this link to join this community.

June 13 - July 4
Black Hole Formation, Accretion, and Outflows Through Cosmic Time

Susanne Aalto, Chalmers University of Technology
Peter Maksym, Center for Astrophysics, Harvard and Smithsonian
*Jessie Runnoe, Vanderbilt University
Tyrone Woods, NRC Herzberg Astronomy & Astrophysics

It is impossible to understand cosmic evolution without also understanding the physics of how supermassive black holes either accrete matter or reject it in the form of outflows, and what impact those have.  The physical processes that occur on the scale of a few gravitational radii are therefore far-reaching: the formation of winds by an active galactic nucleus impact spatial scales spanning over 13 orders of magnitude.  This workshop will address the open questions regarding the interconnected astrophysical phenomena relevant on this range of scales.  Specifically:
  • How do massive black holes form?  What are the detailed physical processes and relative importance of light (population III stars) and heavy (direct collapse) seeds and how can we distinguish observationally between these channels?
  • How do massive black holes grow?  How do time-domain observations and recent spatially resolved results from e.g., the Event Horizon Telescope and GRAVITY constrain accretion theory?  What are the implications for finding supermassive black hole binaries and multi-messenger astrophysics?
  • How do massive black holes generate powerful outflows?  How are winds driven and how do multi-wavelength observations constrain this process?
  • How are MBH growth and star formation entwined over cosmic time?  On what scales do AGN-driven winds impact gas in the host galaxy?  How does AGN feedback's role in galaxy evolution change over cosmic time?
The major topics of this workshop encompass a wide variety of physics that will bring together a multi-disciplinary group with common interests.  Discussion will emphasize the role of new observational facilities studying the distant universe (JWST), time domain and synoptic facilities (SDSS-V, LSST, eROSITA) and the local universe in detail (EHT and the GRAVITY instrument on the Very Large Telescope) in answering these questions. 

June 20 - July 11
New Directions for Quantum Dynamics in Topological, Disordered, and Correlated Systems

Anushya Chandran, Boston University
Marcel Franz, University of British Columbia
*Tamar Pereg-Barnea, McGill University
Smitha Vishveshwara, University of Illinois Urbana Champaign

Quantum dynamics has developed over the past decade into a major field of research, spanning the condensed matter, quantum optical, and high-energy theory communities. During this period, there have been many breakthroughs; for example, on many-body localization and its associated long-lived quantum memory in disordered systems, on novel topological orders that are only possible in periodically driven systems, on realizing and manipulating interacting Majorana modes for quantum computation, and the development of strong bounds on chaos in correlated quantum systems. This workshop aims to push the dynamical frontier in all these settings, paying special attention to the interplay of dissipation, topology and constraints, and new experimental platforms for simulating quantum dynamics.

June 27 - July 25
Exploring Extreme Matter in the Era of Multimessenger Astronomy: from the Cosmos to Quarks

Gordon Baym, University of Illinois Urabana-Champaign
**Slavko Bogdanov, Columbia University
Samaya Nissanke, University of Amsterdam
Sanjay Reddy, University of Washington
*Jocelyn Read, California State University Fullerton
**Thomas Schaefer, North Carolina State University

Multi-messenger observations of binary neutron star mergers (BNS) are pushing forward the frontiers in astrophysics, cosmology and nuclear and gravitational physics.   With detection of several BNS and neutron star--black hole (NSBH) candidate mergers from LIGO-Virgo gravitational wave observations, and expected from future LIG0-Virgo-KAGRA and planned next generation gravitational wave detectors, this four week workshop aims to bring together the observational and theoretical astrophysical communities, along with the high energy nuclear physics community, with the goal of building foundations for using future high sensitivity detections of gravitational radiation (GW) and associated electromagnetic signals of BNS and NSBH mergers to explore in unprecedented detail dense astrophysical matter, and how it governs the physics of neutron stars.

July 11 - August 1
Electronic Topology across the Correlation Spectrum

Peter Armitage, Johns Hopkins University
Silke Buehler-Paschen, Vienna University of Technology
Jennifer Cano, Stony Brook University
*Qimiao Si, Rice University

The topological paradigm enriches quantum phases and their transitions in systems that span the spectrum of weak to strong correlations. In recent years, there have been considerable new developments regarding the topological phases of non-interacting electrons; among these are Weyl and Dirac fermions, space group symmetry classifications, experiments on their electromagnetic responses, higher order topological insulators, and the experimental discovery of an antiferromagnetic topological insulator. In parallel, rapid progress on both theoretical and experimental fronts has taken place in the exploration of electronic topology in strongly correlated systems; this includes the discovery of Kondo-driven Weyl semimetals, as well as the search for signatures of topological states in Kondo insulators and spin-orbit-coupled 5d electron systems. For the most part, however, the two directions have been developing with very limited crosstalk.

This workshop aims to unite the two communities by highlighting the emerging unifying themes of electronic topology across the correlation spectrum. The topics of the workshop will include:

  • the effect of correlations on non-interacting symmetry-protected semimetals
  • weakly interacting topological phases caused by interaction-driven broken symmetries
  • topological states driven by strong correlations
  • the role of space group symmetry for electronic topology of strongly correlated systems
  • entirely new topological states of matter that have no weakly interacting counterparts
  • unifying themes for electronic topology in disparate materials settings

Experimentalists and theorists interested in these and related topics are encouraged to apply.

July 25 - August 29
Dark Matter from the Laboratory to the Cosmos

Kimberly Boddy, Johns Hopkins Univeristy
Katherine Freese, University of Texas at Austin
Mariangela Lisanti, Princeton University
*Benjamin Safdi, University of Michigan
Tien-Tien Yu, University of Oregon

While dark matter is known to comprise most of the matter in the Universe, its microscopic nature remains unknown.  The search for dark matter is entering a new era, with traditional direct detection, collider, and indirect detection searches having produced increasingly strong constraints on some of the most well-motivated dark matter models.  As a result of these constraints, the dark matter community is beginning to explore beyond the traditional search techniques and models.  This workshop will focus on new ideas in the search for particle dark matter, covering a wide range of novel astrophysical tests and direct detection techniques.  By bringing together model-builders, observers, simulators, experimentalists, and phenomenologists, this interdisciplinary gathering will provide a forum to exchange ideas towards the common goal of discovering particle dark matter. 

August 1 - 22
Bootstrapping String Theory

Rajesh Gopakumar, International Centre for Theoretical Physics
Eric Perlmutter, IPhT, CEA Saclay
Silviu Pufu, Princeton University
David Simmons-Duffin, Caltech

It has been long known that conformal field theories (CFTs) appear in string theory in two ways:  firstly, two-dimensional CFTs describe the worldsheet dynamics of fundamental strings; and secondly, through the AdS/CFT correspondence, CFTs provide dual holographic descriptions of string theory defined on target spaces with negative cosmological constant. The past several years have seen major advances in strongly-interacting CFT through the development of numerical and analytical bootstrap techniques that rely on symmetry and consistency conditions. In this workshop, we seek to take stock of these recent developments and investigate whether they can shed light on open questions in string theory and quantum gravity. A central theme will be to formulate rigorous criteria obeyed by CFTs with string theory duals, and to rephrase these criteria as bootstrap problems that can be solved. Moreover, developments in the bootstrap and the simultaneous progress in formal string theory have not been synthesized using a common, modern language, and this workshop presents a prime opportunity to do so. These themes will be explored by way of the following topics: 2d CFT in string theory; effective field theories in AdS and their holographic duals; CFT correlators and string theory scattering amplitudes; Lorentzian approaches to CFT; and the interplay between swampland constraints on quantum gravity and bootstrap principles.  

August 22 - September 19
From Chaos to Hydrodynamics in Quantum Matter

*Victor Galitski, University of Maryland
Aharon Kapitulnik, Stanford University
Leonid Levitov, MIT
**Monika Schleier-Smith, Stanford University
Brian Swingle, University of Maryland

Hydrodynamics is one of the oldest fields in physics, which combines illustrious history of discoveries with a long list of unsolved fundamental problems such as the theory of turbulence and general properties of Navier–Stokes equations. While hydrodynamics is usually associated with the classical macro world, it has recently become clear that electron liquids in a variety of quantum materials behave much like fluids and admit a hydrodynamic description. Recent experiments in graphene, Weyl semimetals, and other materials have demonstrated hydrodynamic electron transport. A closely related class of material are so-called “bad metals,” which are strongly-correlated  electron systems that manifestly violate bounds dictated by the textbook theory of metals. These experimental discoveries go hand in hand with the flurry of recent theoretical interest in “quantum hydrodynamics” and a closely-related field of “many-body quantum chaos.” There have been intriguing developments in this direction, due to a concerted effort of theorists from a variety of fields, from condensed matter to quantum information to general relativity and string theory.  Our program intends to bring together a broad community of experts interested in the hydrodynamic regime of transport of electron materials and more generally in hydrodynamic description of transport, heat transport, and information dynamics of quantum matter.  The workshop intends to share the challenges and recent progress on the solid-state, cold atom, and quantum information frontiers, and to synthesize a common vision for the broad field of quantum hydrodynamics and many-body quantum chaos.

August 29 - September 19
Nu Intersections: Neutrino Physics at a Crossroad

Tao Han, University of Pittsburgh
Marilena LoVerde, Stony Brook University
*Pedro Machado, Fermilab
Cedric Weiland, University of Pittsburgh

Neutrino physics is at a turning point. Several oscillation experiments are being commissioned with three main purposes: carrying out a bona fide precision neutrino physics program; exploring astrophysical neutrino sources; and clarifying once and for all long-standing short baseline neutrino anomalies. Moreover, the LHC is entering its high luminosity stage, probing yet unexplored physics related to the generation of neutrino masses and mixing. Besides, there will be considerable experimental progress in searches for rare processes, involving the violation of lepton number and lepton flavor, which may further enlighten the physics behind neutrino mass and its nature. Finally, future cosmological observations will be sensitive to the absolute value of neutrino masses, testing the three neutrino paradigm in a way complementary to the aforementioned experiments. The goal of the proposed program is to put together this diverse community in order to advance our understanding of the neutrino sector while keeping up with experimental developments in the near future. Topics that will be discussed in the workshop include the following: oscillation physics; beyond standard neutrino physics and BSM physics at neutrino experiments; neutrinos at the LHC; violation of lepton number and flavor; and cosmological and astrophysical neutrinos.

September 5 - 19
New Discoveries in the Era of High-Resolution, Low-Noise CMB Experiments

Simone Ferraro, Lawrence Berkeley National Laboratory
Matthew Johnson, York University
Moritz Munchmeyer,  Perimeter Institute
Neelima Sehgal, Stony Brook University

The cosmic microwave background (CMB) has been an extraordinarily powerful tool, establishing the standard cosmological model and uncovering hints for physics beyond it. An exciting new frontier in CMB science lies in the high-resolution, low-noise regime that future experiments such as the Simons Observatory, CMB-S4, and CMB-HD are targeting. In this regime entirely new sources of temperature and polarization anisotropies, the secondary CMB, associated with e.g. the Sunyaev Zel'dovich effect and gravitational lensing, become accessible. Precise measurements of the secondary CMB in concert with upcoming large galaxy redshift surveys have the potential to provide a transformational new understanding of dark matter, baryonic feedback, reionization, dark energy, primordial non-gaussianity, modifications of general relativity, and inflationary cosmology. This workshop will bring together experts in theoretical and observational cosmology in order to explore the potential for making new discoveries using future observations of the secondary CMB anisotropies. In particular, we propose to tackle questions such as: Do we have a comprehensive theoretical understanding of the secondary CMB, including all potentially detectable effects? What are the best strategies for extracting cosmological information from the secondary CMB, including cross-correlations with other datasets? What are the most challenging foregrounds and systematics that future experiments will contend with, and how can they be mitigated? We hope that this workshop will catalyze not only practical developments relevant to the analysis of imminent data, but also blue sky thinking about how cosmology might be done differently with the secondary CMB.