The year 2023 marks the centenary of the birth of Louis Michel, the first Professor of Theoretical Physics at IHES. On this occasion, Thibault Damour and Slava Rychkov organize a one-day commemoration on May 15, 2023, at IHES.

Several presentations will be given by lecturers linked to Louis Michel or to his work:

• Jean-Pierre Bourguignon, CNRS-IHES
• Henri Epstein, CNRS-IHES
• Denis Gratias, CNRS-Institut de Recherche de Chimie Paris
• David Ruelle, IHES
• Slava Rychkov, IHES
• Marjorie Senechal, Smith College
• Boris Zhilinskii, Univ. du Littoral Côte d’Opale

Program

To participate in the commemoration of Louis Michel’s centenary, registration is free but mandatory on the dedicated web page.

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Louis Michel (1923-1999),
Permanent Professor at IHES from 1962 to 1992.

Louis Michel was the first Permanent Professor in Theoretical Physics at IHES, which he joined in 1962. His scientific work made pioneering contributions in a wide area of theoretical physics, ranging from particle physics to crystallography. At IHES, Louis Michel found an appropriate setting to develop the leitmotiv of his scientific work: to deepen the mathematical roots underlying the symmetries of the laws of nature.

For a detailed analysis of Louis Michel’s scientific work, see the website created on the occasion of his 90th birthday, and the book Symmetries in Nature: The Scientific Heritage of Louis Michel (World Scientific Series in 20th Century Physics) edited by Thibault Damour, Ivan Todorov and Boris Zhilinskii (2014).

In order to honor his memory, IHES created in 2000 the Louis Michel Chair of Theoretical Physics for long-term visitors.

The main themes of his research at IHES – and his main collaborators – are:

• Relations between internal symmetries and relativistic invariance,
• Theory of spontaneous symmetry breaking and its application to high energy physics and the Jacobi ellipsoid, with Luigi A. Radicati, then to condensed matter physics, with Maurice Kléman and Gérard Toulouse,
• A general formalism for the description of the polarization of particles of any spin, with Manuel G. Doncel and Pierre Minnaert,
• Mathematical crystallography and representation of crystallographic groups, with Jan Mozrzymas and Boris Zhilinskii,
• New applications of symmetry to energy bands in solids, with Joshua Zak,
• The geometry of Euclidean lattices, with Marjorie Senechal.

Louis Michel played a significant role in the reconstruction of French Theoretical Physics in the 1950s. The list of his students bears witness to this in a striking way: Claude Bouchiat, Claude de Calan, Manuel Doncel, Henri Epstein, Gérard Flamand, Dimitri Fotiadi, Gérard Fuchs, Jean-Loup Gervais, Pierre Minnaert, Jean Nuyts, Eduardo de Rafael, Houcheng Rouhaninejad (= Henri Roane), Roland Seneor, Paul Sorba, and Raymond Stora (last in alphabetical order but first in chronological order).

For more information, see La Vie et l’Œuvre Scientifique de Louis Michel (in French), and the website.

Damour Fest
Adventures in Gravitation

 

To celebrate the 70th birthday of Thibault Damour, permanent professor at IHES since 1989, a “Damour Fest”, gathering friends with whom he enjoys interacting around Gravitational Physics and beyond, was held at IHES from Tuesday 12 October afternoon to Friday 15 October 2021 noon. It was organised by Nathalie Deruelle (APC, Université de Paris), Alessandro Nagar (INFN Torino) and Slava Rychkov (IHES).

The following speakers talked (a few remotely) on topics of their choice reflecting their current interest:

– Leor Barack, University of Southampton
– Sebastiano Bernuzzi, University of Jena
– Lydia Bieri, Michigan University
– Luc Blanchet, IAP, Paris
– Alessandra Buonanno, AEI, MPI, Potsdam
– Sophie De Buyl, Vrije Universiteit Brussel
– Stanley Deser, Brandeis University
– Marc Henneaux, Collège de France & ULB Bruxelles
– Bala Iyer, ICTS, TIFR, Bangalore 
– Piotr Jaranowski, University of Białystok
– Sergiu Klainerman, Princeton University
– Michael Kramer, MPI, Bonn
– Juan Maldacena, IAS, Princeton
– Viatcheslav Mukhanov, Ludwig Maximilian University, Munich
– Hermann Nicolai, AEI, MPI, Potsdam
– Adam Pound, University of Southampton
– Giuseppe Policastro, ENS Paris
– Alexander Polyakov, Princeton University
– Manuel Rodrigues, ONERA, Université Paris-Saclay
– Remo Ruffini, ICRA, Rome
– David Shoemaker, MIT
– Sergey Solodukhin, University of Tours
– Alexei Starobinski, Landau Institute, Moscow
– Gabriele Veneziano, CERN & Collège de France
– Alex Vilenkin, Tufts University
– Edward Witten, IAS, Princeton

To apply, get more information about the schedule, and be informed of the latest actions, visit the conference web page.

The conference was held in a blended form, with talks given on-site at IHES and others remotely through Zoom. All the talks could be followed either online or on-site (subject to availability).

Covid-19 regulations: for those who will attend in person, masks will be mandatory and we will ask them to provide a health pass upon their arrival.

Find all the videos of the Damour Fest:

The 2021 IHES Summer School on “Enumerative Geometry, Physics and Representation Theory“, held from 5 to 16 July, was organized in a blended version, in which some participants were at IHES in person, and others will participate over Zoom.

This school is open to everybody but intended primarily for young participants, including Ph.D. students and postdoctoral fellows.

The organising committee includes Andrei Negut (Massachussetts Institute of Technology), Francesco Sala (Università di Pisa) and Olivier Schiffmann (CNRS, Faculté des Sciences d’Orsay, Université Paris-Saclay).

Mina Aganagic (University of California at Berkeley), Hiraku Nakajima (Kavli IPMU), Nikita Nekrasov (Simons Center for Geometry and Physics), and Andrei Okounkov (Colombia University) are the members of the scientific committee.

Enumerative Geometry, Physics and Representation Theory

The main theme of this Summer School is enumerative geometry, with particular emphasis on connections with mathematical physics and representation theory. As its core, enumerative geometry is about counting geometric objects. The subject has a history of more than 2 000 years and has enjoyed many wonderful breakthroughs in the golden years of classical algebraic geometry, but we will be interested in more recent developments.

The 2021 Summer School will focus on the following main subjects with mini-courses and advanced talks given by international experts:

• counting curves and sheaves (Gromov-Witten theory, Donaldson-Thomas and related theories);
• gauge theory enumerative geometry (3d gauge theories and Coulomb branches, 4d gauge theories, and Vafa-Witten invariants, etc.);
• applications of enumerative geometry to categorification and low-dimensional topology;
• Hall algebras and their refined versions (cohomological, K-theoric, derived categories).

Mini-courses given by:
Eugene Gorsky (University of California at Davis), Joel Kamnitzer (University of Toronto), Davesh Maulik (Massachusetts Institute of Technology), Rahul Pandharipande (ETH Zürich), Markus Reineke (Ruhr-Universität Bochum), Richard Thomas (Imperial College London).

Advanced Talks given by:
Pierrick Bousseau (CNRS and Université Paris-Saclay), Alexander Braverman (University of Toronto and Perimeter Institute for Theoretical Physics), Tudor Dimofte (University of California at Davis and University of Edinburgh), Lothar Gottsche (ICTP), Michael Groechenig (University of Toronto), Maxim Kontsevich (IHES), Georg Oberdieck (Mathematisches Institut der Universität Bonn), Richard Rimanyi (University of North Carolina at Chapel Hill), Peng Shan (Tsinghua University), Dimitri Zvonkine (Laboratoire Mathématiques de Versailles).

Information on the dedicated web page.

Find all the videos of the summer school :

 

From February 10 to 14, 2020, the Institut des Hautes Études Scientifiques hosted the conference “Integrability, Anomalies and Quantum Field Theory“. Organised by Anton Alekseev (University of Geneva) and Maxim Kontsevich (IHES), this conference honoured Professor Samson Shatashvili on his 60^th birthday.

The interactions of Mathematics and Physics have greatly intensified during the last three decades, and it led to a number of very significant breakthroughs in Mathematics. Among other things, these breakthroughs include new invariants of 3 and 4-dimensional manifolds, the discovery of mirror symmetry in Algebraic Geometry, and the theory of deformation quantization.
This progress became possible due to close interactions between Mathematics and theoretical Physics and due to the dialogue between mathematicians and physicists working on similar problems but using very different methods.

The conference touched upon two important aspects of interaction between Mathematics and Quantum Field Theory.

Quantum Integrability is a very interesting theory which was first discovered on the Physics side. It was soon realized that it is related to Algebra through the theory of Vertex Operator Algebras (VOA) and to Complex Analysis (through the study of various Riemann-Hilbert problems). The problem of Bethe Ansatz completeness became an important mathematical problem and a driving force in Combinatorics and Representation Theory. Recently, relations between quantum integrability and Geometric Representation Theory (on the Mathematics side) and Quantum Gauge Theory (on the Physics side) attracted a lot of attention of the research community. These links will be one of the major topics of the conference.

Anomalies were discovered in Physics as the phenomenon when symmetry of a system changes under quantization. Famously, it occurs in gauge theories and in string theory, and it serves as one of the key criteria for choosing realistic models of field theory. Anomalies also became one of the important topics in Mathematics. They are related to the behaviour of determinant bundles of Dirac operators on manifolds, to the index theory and to K-theory. In many cases, anomalies represent the part of Quantum Field Theory which can be defined and computed mathematically. Anomalies will be one of the key topics of the meeting.

Professor Samson Shatashvili made deep contributions in the theory of anomalies and in quantum integrability. In particular, in collaboration with Ludwig Faddeev he discovered the interpretation of gauge theory anomalies in terms of abelian extensions of gauge groups on manifolds of odd dimension. In the theory of quantum integrability, together with a number of collaborators he discovered a deep link between Bethe equations and supersymmetric quantum gauge theory.
Professor at the Trinity College, Dublin and at the Simons Center for Geometry and Physics, Stony Brook, he served as a Louis Michel Chair and then as an Israel Gelfand Chair at IHES. He contributed in a significant way in the development of ideas and in the unique research atmosphere of IHES.

Invited speakers were:
Costas Bachas (ENS-Paris), Jean-Michel Bismut (Université Paris-Sud Orsay), Gregory Gabadadze (New York University), Sergei Gukov (Caltech), Simeon Hellerman (IPMU), Chris Hull (Imperial College London), Vladimir Kazakov (ENS-Paris), Zohar Komargodski (SCGP), Vladimir Korepin (Stony Brook University), Manuela Kulaxizi (Trinity College Dublin), Sergei Lukyanov (Rutgers University), Ruben Minasian (IPhT & CEA Saclay), Vasily Pestun (IHES), Alexey Rosly (ITEP, Skoltech, HSE, IITP, Moscow), Sinead Ryan (Trinity College Dublin), Ivo Sachs (LMU Munich), Nana Shatashvili (Tbilisi State University, Georgia), Fedor Smirnov (LPTHE Sorbonne-Université), Leon Takhtajan (Stony Brook University), Anne Taormina (Durham University), Cumrun Vafa (Harvard University), Pierre Vanhove (IPhT & CEA Saclay), Erik Verlinde (Universiteit van Amsterdam), Alexander Zamolodchikov (Stony Brook University).

Programme and registration on the conference web page.

Video playlist of the conference:

As part of the ERC Starting Grant N° 677368 QUantum Algebraic Structures In Field Theories (QUASIFT), the conference “Higher Structures in Holomorphic and Topological Field Theory” was held at IHES from 14 to 18 January 2019.

Organized by Christopher ELLIOTT (post-doc QUASIFT at IHES) and Vasily PESTUN (Principal Investigator and permanent professor at IHES), this conference aimed to unite physicists and mathematicians working on higher structures in quantum field theories for them to discuss about the application of physical concepts in algebraic geometry and homotopy theory. The conference focused on different topics, such as the structures associated to line and surface operators, the cobordism hypothesis or factorization homology.

Invited speakers were: David AYALA (University of Montana), Alexander BRAVERMAN (University of Toronto), Damien CALAQUE (University of Montpellier), Emily CLIFF (University of Illinois), Owen GWILLIAM (University of Massachusetts), Justin HILBURN (University of Pennsylvania), David JORDAN (University of Edinburgh), Nikita NEKRASOV (SCGP, Stony Brook), Miroslav RAPČÁK (Perimeter Institute), Jie REN (IHES), Pavel SAFRONOV (University of Zurich), Claudia SCHEIMBAUER (NTNU Trondheim), Brian WILLIAMS (Northeastern University), Junya YAGI (University of Warsaw), Philsang YOO (Yale University).

Visit the conference web page for more information.