Organizers: Massimo D’Elia, Jeff Greensite, Elias Kiritsis, Zohar Komargodski, Edward Shuryak, Jacob Sonnenschein, Ismail Zahed

A workshop on these topics was supposed to start in June 2020 at the Simons Center of Stony Brook University, but this in-person meeting is now delayed to June 7, 2021. This will mean a roughly two year gap since the last meeting concerned with these issues, and, in order to fill that gap, the organizers have decided to run a series of summer seminars via Zoom.

We plan to have ZOOM MEETINGS twice a week, MONDAYS and THURSDAYS:

US West coast 9-10:00; US East coast 12:00-13:00; Western Europe 18:00-19:00 ; Greece/Israel 19:00-20:00;

In order to get zoom meeting parameters and to get weekly mailing on current seminar titles, one needs to register with Simons Center. If you have not received a formal invitation please apply to the event here: Application.

By “gauge topology” we mean phenomena induced by instantons, instanton-dyons, magnetic monopoles, and center vortices. The topic also comprises the physics of sphalerons and their explosions, in the QCD phase transition and the electroweak cosmological phase transition.

Holographic models describe the strong-coupling limit of QCD, and they have been used for description of hadronic spectroscopy and wave functions, finite temperature QCD, as well as near- and out-of equilibrium kinetics. String models of hadrons were originally introduced to describe the spectra and scatterings of hadrons. Inspired by holography, they have been recently improved and their connection to QCD deepened. Perhaps some other problems of nonperturbative QCD will also be discussed. We will try to start with some general reviews of subfields, before proceeding to original works.

Date | Title | Speaker | Abstract |

6/1 | Sphalerons and baryogenesis in cosmological electroweak transition of the minimal standard model | Edward Shuryak | Abstract |

6/4 | The Holography inspired stringy hadron model (HISH). A review and Open questions | Jacob Sonnenschein | Abstract |

6/8 | Topological susceptibility and related quantities on the lattice | Mariapaola Lombardo | Abstract |

6/11 | Reggeized scattering, entanglement and chaos using AdS/CFT | Ismail Zahed | Abstract |

6/15 | Centre vortices as the origin of confinement | Waseem Kamleh | Abstract |

6/22 | Topological Objects Near Tc: Instanton dyons in Theory and on Lattice | Rasmus Larsen | Abstract |

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Organized by: Ranny Budnik, Rouven Essig, and Maxim Pospelov.

Continuing progress in collider physics and dark matter searches in the past few decades have put significant pressure on several favorable theoretical models for Dark Matter and other beyond the Standard Model physics.

However, the mystery of dark matter, and its true identity in relation to the rest of the micro-world, remains unsolved, which has led in the past few years to an explosion of ideas for experimental searches in different, novel directions.

We will hold a program that puts at its center the question to both theorists and experimentalists: where should we be looking for new physics? We will focus on novel searches for Dark Matter and other new physics, as well as on new theoretical ideas that open up new directions that require further theoretical or experimental development. Each participant will be expected to share her or his view on where new searches are most likely to find new physics.

]]>

The goal of the program is to bring together mathematicians and physicists working on various aspects of renormalization in dynamical systems. The idea of Renormalization group emerged in Quantum Field Theory. Later, in the 1960s, it became a major tool in Statistical Mechanics in analysis of phase transitions and critical phenomenon. One can say that the ideas of renormalization group have revolutionized the field. This development culminated in Wilson’s expansion based on his ideas on intrinsic relation between physical parameters in different scales.

In the 1970s the renormalization ideology was transferred to Dynamics in the context of Universality discoveries by Feigenbaum, Coullet and Tresser, and has since become one of the most powerful tools of understanding small scale structure of a large variety of systems. It has become particularly well (and rigorously) developed in the Conformal context, in particular, in the geometric problems related to the celebrated MLC Conjecture on the local connectivity of the Mandelbrot set.

Today, the renormalization ideas have penetrated deeply into many areas of Mathematics and Physics, but an explicit relation between various areas often remains elusive. One of our goals is to look for a unifying approach that would cover various manifestations of the renormalization.

In the first part of the program we will focus on conformal aspects that would include small scale structure of the dynamical and parameter loci of conformal dynamical systems, small scale properties of Brownian motions and harmonic measures, SLE, random conformal welding, and other relevant systems. We shall also discuss other aspects of dynamical renormalization, including related area of renormalization for quasi-periodic Schr ̈odinger operators.

In the second part, we will explore renormalization in various physical situations: QFT, fluid dynamics, and statistical mechanics, including KPZ phenomenon, with the emphasis on the underlying stochastic mechanisms responsible for the statistical

scaling invariance.

There are a few workshops associated with this program: Renormalization retrospective: Feigenbaum Memorial Conference: March 5-7, 2021, which will serve as an introduction to the SCGP Workshop Many Faces of Renormalization: March 8-12, 2021.

]]>Organized by: Ranny Budnik, Rouven Essig, and Maxim Pospelov.

Attendee List

Continuing progress in collider physics and dark matter searches in the past few decades have put significant pressure on several favorable theoretical models for Dark Matter and other beyond the Standard Model physics.

However, the mystery of dark matter, and its true identity in relation to the rest of the micro-world, remains unsolved, which has led in the past few years to an explosion of ideas for experimental searches in different, novel directions.

We will hold a program that puts at its center the question to both theorists and experimentalists: where should we be looking for new physics? We will focus on novel searches for Dark Matter and other new physics, as well as on new theoretical ideas that open up new directions that require further theoretical or experimental development. Each participant will be expected to share her or his view on where new searches are most likely to find new physics.

******Please note as of March 23rd the program has been postponed and will be rescheduled for another date.******

When a system of differential equations has an irregular singularity, such as a pole of order two or higher, a solution may fail to have a well-defined asymptotic expansion at the singular locus. Instead, there is a collection of angular sectors surrounding the singular locus, in each of which an asymptotic expansion is defined. The existence of such sectorial asymptotic expansions is what is called the “Stokes phenomenon”.

The Stokes phenomenon has found remarkable applications in different areas of mathematics and physics, such as in cohomological field theory, the study of Bridgeland stability conditions, noncommutative Hodge theory, cluster algebras, quantum groups and so on. In particular, the Stokes phenomenon is the essential ingredient in an irregular version of the Riemann-Hilbert correspondence, where the moduli space of differential equations with irregular singularities is described in terms of its associated generalized monodromy data (Stokes matrices). The geometric nature of this Riemann–Hilbert map from the moduli space of differential equations or “de Rham moduli space” to the space of Stokes matrices or “Betti moduli space” has been intensively studied for the past twenty years. Moreover, the crucial role of the Stokes phenomenon in the study of representation theory and integrable systems is only beginning to emerge.

The overall goal of the program is to bring together specialists in the above mentioned topics to exchange a ideas and perspectives, with the aim of breaking new ground in these related fields of physics and mathematics.

]]>Live video may be available, please take a look at http://scgp.stonybrook.edu/live.

The availability of very large datasets and the striking progress in artificial intelligence are revolutionizing the way scientists approach their disciplines. The deployment of state-of-the-art techniques in machine learning and statistical inference to study large datasets is leading to unprecedented discoveries and narrowing the gap between physics, mathematics, biology, computer science, and statistics. Despite this practical success, little is known about the general principles governing neural networks learning and dynamics and the geometry of data manifolds. The Simons Program on “Neural networks and the Data Science Revolution” will bring together researchers from the theoretical physics, artificial intelligence, and computational neuroscience communities to discuss foundational and theoretical aspects of neural networks, and highlight challenges and opportunities in their application to specific open problems along an axis of topics encompassing string theory, machine learning, big data science, and brain science. The program will begin with a workshop on the interface between theoretical physics, geometry and data science, with a focus on synthetic datasets arising in the classification of manifolds and knots, quantum and statistical field theories, and vacuum configurations of string theory. The program will end with a workshop on the physics of neural circuits, discussing ways to bridge the gap between neural network models and the large experimental datasets nowadays available in neuroscience.

This event is co sponsored by the Department of Neurobiology and Behavior and the Center for Neural Circuits Dynamics

This program will also be hosting two workshops Strings, Geometry, and Data Science: January 6-8, 2020 and Physics of neural circuits and network dynamics: January 27-31, 2020

We will be conducting virtual zoom seminars in response to the social distancing measures currently in place in New York. These seminars are taking place generally on Fridays at 2:30pm. You can find information about upcoming seminars on our calendar here: http://scgp.stonybrook.edu/calendar/full-calendar

Organizers: Dzmitry Dudko, Kostya Khanin and Misha Lyubich

The goal of the program is to bring together mathematicians and physicists working on various aspects of renormalization in dynamical systems. The idea of Renormalization group emerged in Quantum Field Theory. Later, in the 1960s, it became a major tool in Statistical Mechanics in analysis of phase transitions and critical phenomenon. One can say that the ideas of renormalization group have revolutionized the field. This development culminated in Wilson’s expansion based on his ideas on intrinsic relation between physical parameters in different scales.

In the 1970s the renormalization ideology was transferred to Dynamics in the context of Universality discoveries by Feigenbaum, Coullet and Tresser, and has since become one of the most powerful tools of understanding small scale structure of a large variety of systems. It has become particularly well (and rigorously) developed in the Conformal context, in particular, in the geometric problems related to the celebrated MLC Conjecture on the local connectivity of the Mandelbrot set.

Today, the renormalization ideas have penetrated deeply into many areas of Mathematics and Physics, but an explicit relation between various areas often remains elusive. One of our goals is to look for a unifying approach that would cover various manifestations of the renormalization.

In the first part of the program we will focus on conformal aspects that would include small scale structure of the dynamical and parameter loci of conformal dynamical systems, small scale properties of Brownian motions and harmonic measures, SLE, random conformal welding, and other relevant systems. We shall also discuss other aspects of dynamical renormalization, including related area of renormalization for quasi-periodic Schr ̈odinger operators.

In the second part, we will explore renormalization in various physical situations: QFT, fluid dynamics, and statistical mechanics, including KPZ phenomenon, with the emphasis on the underlying stochastic mechanisms responsible for the statistical

scaling invariance.

There is a workshops associated with this program: Analysis, Dynamics, Geometry and Probability: March 2-6, 2020.

]]>Organized by: Luis Alvarez-Gaume, Simeon Hellerman, Domenico Orlando, and Susanne Reffert

QFT is the basic paradigm for the description of condensed matter physics and high-energy particle physics. Despite decades of research, strongly coupled regimes of QFT are largely inaccessible to analytic methods, even though important progress has come from the conformal bootstrap and non-Lagrangian methods.

This program will be dedicated to exploring the asymptotic directions of the space of amplitudes in strongly coupled QFT, particularly the case of large quantum number under an internal and/or rotational symmetry. We will make use of many different methods to explore such limits, including the conformal bootstrap, Monte Carlo simulations, supersymmetric localization and recursion relations, and the most recently-applied method, the use of effective field theories that describe the large-charge limit of strongly interacting systems, with

the total charge as a loop-suppressing parameter. Working in sectors of large global charge allows us to perform a perturbative expansion for strongly coupled theories without any small parameters, with the

inverse of the total charge itself, as the perturbation parameter suppressing quantum fluctuations and unknown terms in the effective action.

Another aim of the program is to better understand the connections between the different approaches to large quantum number physics that are emerging. In particular understanding the connection between the study of systems at large spin via the light-cone bootstrap and the large-charge approach would be of major importance.

The study of the large-quantum-number regime is a subject still in its infancy, with a number of rapidly developing directions and applications. Apart from the issues explicitly mentioned here, the LQN expansion appears to be a special case of a more general set of phenomena in which strongly coupled systems self-classicalize in various limits of “observable space”. Such examples include resurgence theory, Regge theory, supersymmetric localization, and the macroscopic limit of quantum thermodynamics. A key goal of the program is to discover the most natural context containing the large quantum-number expansion in its current form.

We hope that this program aimed to develop these connections and applications will meet with wide interest!

**Schedule of Talks: All talks will take place in room 313. Videos can be found here: http://scgp.stonybrook.edu/video/results.php?event_id=275**

Monday 8/26 | 2:00pm | Simeon Hellerman | Large quantum numnber: Pverview and some recent developments |

Tuesday 8/27 | 10:00am | Domenico Orlando | Large charge at large N |

Wednesday 8/28 | 11:00am | Nozomu Kobayashi | Towards a C-theorem in defect CFT |

Tuesday 9/3 | 11:00am | Shailesh Chadrasekharan | Monte Carlo calculations of conformal dimensions of large charge operators |

Tuesday 9/3 | 2:30pm | Philip Argyres | |

Wednesday 9/4 | 11:00am | Riccardo Rattazzi | |

Thursday 9/5 | 11:00am | Francesco Sannino | Safe Interactions Guaranteed: New directions |

Friday 9/6 | 11:00am | Zohar Komargodski | Large-Charge/Random-Matrix Duality |

Monday 9/9 | 2:00pm | Gabriel Cuomo | Superfluids, vortices and spinning charged operators in CFTs |

Tuesday 9/10 | 10:00am | Andrew Gasbarro | Curved Lattice Field Theory for CFT Data |

Wednesday 9/11 | 11:00am | Shauna Kravec | The Large Charge Expansion for Non-Relativistic CFTs |

Thursday 9/12 | 11:00am | Dalimil Mazac | Sphere Packing and Quantum Gravity |

Thursday 9/12 | 1:00pm | Alberto Nicolis | Spontaneously broken boosts and the Goldstone continuum |

Friday 9/13 | 11:00am | Masataka Watanabe | Chern-Simons-matter theory at Large Charge |

Tuesday 9/17 | 10:00am | Sridip Pal | Asymptotics in 2D CFT and Tauberian Theorems |

Thursday 9/19 | 3:30pm | David Pirtskhalava | Field Theory for Quantum Matter in Dwarf Stars |

Friday 9/20 | 11:00am | Anton de la Fuente |

Topological phases of matter are a long-standing subject of interest in the condensed matter community, and increasingly relevant to issues in high-energy physics. A topological phase is traditionally defined to be one which is “non-trivial” (cannot be deformed to a trivial insulator without a phase transition), but where the non-triviality cannot be ascribed merely to spontaneous symmetry breaking. Another interpretation is that the word “topological” in “topological phase” is supposed to suggest that the low-energy physics of this phase (that is, the infrared fixed point controlling the phase in the renormalization group sense) is “topological”, meaning that it can be defined on any background space-time and is sensitive only to the background topology. This program will be devoted to exploring the connections, and tension, between these two distinct notions of “topological”. The program will focus on encouraging cross-fertilization between three rapidly developing, interconnected research areas:

The past decade witnessed an explosion of activity in research on symmetry-protected topological phases. Traditionally, the symmetry group in question is either time-reversal or an internal, “on-site’’ symmetry. However, in the past several years, topological phases protected by spatial (crystalline) symmetries have emerged. Unlike topological phases described by topological quantum field theories, these phases a priori can only be defined on the particular background space-time on which the crystalline symmetries act. Consequently, the traditional approach of topological quantum field theory has to be supplemented with additional information, such as the properties of lattice defects,

which are a kind of geometric response of the system. A generic bulk-edge correspondence for these states is absent because, unlike on-site symmetries, crystal symmetries are typically broken on boundaries. In some instances, the usual correspondence is replaced by a “higher-order’’ correspondence between the d-dimensional bulk state and symmetry-preserving (d-2)-dimensional edges. Developing a systematic theory of such phases, and discovering physical examples, is an important open question.

Several years ago, a conceptually new type of gapped phases was discovered. These phases are known as fracton phases, due to the presence of topologically non-trivial excitations that can only move on lower-dimensional submanifolds, or cannot move at all. Like spatial symmetry-protected topological phases, fracton phases challenge our notion of what “topological order” means, because the low-energy theory depends on some non-topological features of space. In fact, these phases also appear to have a very complicated relationship with the geometry of the space where they reside. Intuitively, the exotic features of the excitations in these models can be viewed as stemming from a non-trivial interplay between translation symmetry and topological order. Alternatively, these phases can be viewed as higher-rank gauge theories obtained by gauging the subsystem symmetries — the symmetries which act along lower-dimensional subspaces. Fractons have attracted a broad interdisciplinary interest due to their potential relationship to lattice gauge theory, quantum computation and memory, elasticity, glassy dynamics and emergent gravity in condensed matter.

Fractional quantum Hall states exhibit a non-trivial geometric response. Since FQH phases are liquids, with continuous rotational and translational symmetries, these geometric properties are intuitively related to those of topological phases with spatial symmetries. Developing a rigorous unified approach to the geometric properties of FQH phases on equal footing with the topological phases with crystalline symmetrie will be another focus of the program. Separately, the breaking of discrete and/or continuous crystalline symmetries underpins a remarkable class of unconventional nematic quantum Hall liquids — with unusual properties analogous to those of liquid crystals familiar from classical soft condensed matter physics. Concurrently, there has been recent progress on the FQH physics that goes beyond the topological order paradigm. This builds on pioneering work by Haldane, who has argued that certain collective modes supported by a FQH liquid can be described by a fluctuating geometry. This area of study has recently witnessed further progress simultaneously on three fronts: in terms of trial states, Matrix Models, and effective theory. Quantitative properties of these modes are related to the geometric responses.

Geometry plays a central role in these topics, but currently there is no coherent picture that unifies them. Nevertheless, there are some tantalizing hints of possible close connections. We expect that the program will lead to identification of the common themes and cross-fertilization of these fields.

The program is accompanied by a workshop New directions in topological phases: from fractons to spatial symmetries.

]]>Organized by: Boris Altshuler, Anatoly Dymarsky, Lea Santos, and Jacobus Verbaarschot

**Program seminars will take place on Tuesdays and Thursdays at 2:30pm and Fridays at 11:30am in room 313. To view the schedule of upcoming talks please visit: http://scgp.stonybrook.edu/calendar/full-calendar**

Dynamics of quantum many-body systems is attracting extensive attention across different fields of physics: theoretical and experimental condensed matter, AMO physics, high energy theory, quantum information, and others. Remarkable progress has been achieved in the past years understanding thermalization, or lack thereof, of isolated quantum systems, paving new ways to quantitatively probe quantum chaos and connecting many-body systems to quantum gravity. However, this progress is still fragmentary and there are very important basic questions which are not well understood. The program will address, among others, the following questions.

1) What are the characteristic timescales of relaxation and thermalization for many-body quantum systems? The interplay between different timescales and their manifestation in various observables is not clear. One highly contested question is the behavior of the so-called Thouless time, which marks the scale of applicability of Random Matrix Theory to describe correlations of energy spectrum. For the disordered single-particle systems the latter was identified as the timescale of diffusion. For various many-body systems (local 1D systems, Floquet, SYK model) the Thouless time was shown recently to behave very differently.

2) What is the relation between out-of-time-ordered correlators (OTOC) and the timescales marking the onset of universal behavior? This question is in its infancy with very few papers making explicit connection between dynamics of thermalization and quantitative manifestations of quantum chaos.

3) What constitutes ergodic behavior for quantum systems? Ergodicity for quantum systems is often equated with Eigenstate Thermalization, which is only concerned with the value of observables at equilibrium. Can something be said about the approach toward and fluctuations around the asymptotic value?

4) What is the scope of applicability of Random Matrix Theory to many-body systems? Random matrices are known to describe various aspects of quantum chaotic systems, e.g. statistics of energy levels. More recently, there have been several applications of random matrices to describe the late time behavior of various observables, including survival probability, correlation functions, Euclidean partition function, etc. An important question would be to understand which dynamical quantities and to what they extent may exhibit universal behavior and be described by the Random Matrix Theory.

The program is accompanied by a workshop Applications of Random Matrix Theory to many-body physics, to be held between September 16-20, 2019, which will be focused on universal behavior of many-body systems.

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