The conference was held at IHES depending on the evolution of health situations and related restrictions.

The conference “Large-scale Limits of Interacting Particle Systems”, took place in the Marilyn and James Simons Conference Center from October 4 to 8 2021, and simultaneously on Zoom.

It was organized by Mitia Duerinckx (CNRS), Sergio Simonella (CNRS) and Raphael Winter (École Normale Supérieure de Lyon), with the support of the CNRS-Momentum program.

These five days brought together researchers interested in rigorous methods for the study of scaling limits of interacting particle systems.

The conference focused on three mini-courses, given by:

• Mathieu Lewin (CNRS): “Mean-field Limits and Bose-Einstein Condensation for Quantum Gases“;
• Laure Saint-Raymond (IHES): “Statistical Description of a Hard Sphere Gas Dynamics“;
• Manfred Salmhofer (Institute for Theoretical Physics, Univ. of Heidelberg): “Diagrammatic Expansions and Renormalization in Quantum Dynamics”

The program also included one-hour talks given by:

• Serena Cenatiempo (GSSI),
• Charles Collot (Cergy Paris Université),
• Sabine Jansen (LMU),
• Jens Marklof (University of Bristol),
• Alessia Nota (Università degli Studi dell’Aquila),
• Peter Pickl (University of Munich),
• Marcello Porta (SISSA),
• Mario Pulvirenti (Università di Roma « La Sapienza »),
• Nicolas Rougerie (UMPA),
• Florian Theil (University of Warwick),
• Bálint Tóth (University of Bristol).

To get more information on the conference program, and be informed of the latest measures taken, go to the dedicated web page.

Find all the videos of the conference:

Depending on the evolution of the health situation and related restrictions, two options are currently planned at this time for the conference “Geometry in Non-positive Curvature and Kähler Groups”:
• a fully online conference;
• a hybrid conference: both at the Institute and online. 
Register to get the latest information.

An international conference at IHES

IHES is slowly getting back to its conference rhythm and will host the conference “Geometry in Non-positive Curvature and Kähler Groups”. Organized by Rémi Coulon (University of Rennes 1), François Dahmani (University of Grenoble-Alpes) and Alexandre Martin (Heriot-Watt University), it will be held from 30 August to 1 September 2021.

During three days, several speakers will discuss group geometry, a field at the interface between algebra, geometry, and topology. They will review recent developments in the group geometry with hyperbolic features, Kähler geometry, and their interactions.

This event will also be the occasion to celebrate Thomas Delzant’s (University of Strasbourg) 60^th birthday , a researcher recognized for his contributions to these fields which have had a great influence on the development of geometric group theory.

To apply, get more information about the schedule, and be informed of the latest actions, click here.

 

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Confirmed speakers:

– Goulnara Arzhantseva (University of Vienna),
– Martin Bridson (University of Oxford),
– Serge Cantat (University of Rennes 1),
– Cornelia Drutu (University of Sciences and Technologies of Lille),
– Mikhail Gromov (IHES),
– Vincent Guirardel (University of Rennes 1),
– Panagiotis Papasoglu (University of Oxford),
– Pierre Py (University of Strasbourg),
– Zlil Sela (Einstein Institute of Mathematics).

 

 

Thomas Delzant, a geometric group theory specialist!

After working on symplectic geometry including the study of Hamilton actions, Thomas Delzant has dedicated his work to group geometry. After Misha Gromov‘s seminal treatise on hyperbolic groups in 1987, Thomas Delzant played a key role in the development and popularisation of this emerging field back then. In particular, his lecture notes in collaboration with Michel Coornaert and Athanase Papadopoulos fostered the emergence of a generation of group geometers in France and abroad.

Thomas Delzant’s research in group geometry is varied, but some central topics can be identified, in particular the study of geometries with negative or zero curvature. His work on the structure of hyperbolic groups, as well as his collaboration with Misha Gromov on groups with small simplification, have led to a better understanding of free Burnside groups. His recent work focuses on the structure of Kählerian groups, a still mysterious class of groups at the intersection of complex geometry and symplectic geometry: the central problem is to determine strong constraints on groups of Kählerian varieties. Thomas Delzant uses many tools from group geometry (hyperbolic geometry, cubic CAT(0), etc.) to study these groups. His collaborations with Misha Gromov and Pierre Py have led to a better understanding of cubulable Kähler groups and the image of these groups in surface groups.

 

 

Friday 11 June 2021, H.S.H. Prince Albert II of Monaco came to the Institut des Hautes Etudes Scientifiques, along with Patrice Cellario, the Principality of Monaco’s Minister of Interior.

After having been formally greeted by Marwan Lahoud, President of IHES, Emmanuel Ullmo, Director of IHES, Alexander Grimaud, Sub-prefect of the district of Palaiseau and Jean-François Vigier, Mayor of Bures-sur-Yvette, they met three junior researchers currently at the Institute:

– Veronica Fantini, an Italian mathematician specializing in geometry and mathematical physics, is currently a visitor at IHES, where she will start a post-doc in September;

– Vasilisa Nikiforova, a Russian post-doc in theoretical physics;

– Alex Takeda, a Brazilian post-doc working on topics related to algebraic geometry and mathematical physics.

In the main scientific building of the Institute, H.S.H. Prince Albert II of Monaco was then able to discuss with Fanny Kassel, mathematician, a CNRS researcher based at IHES, and one of her PhD students, Balthazar Fléchelles. The Institute is thus part of a larger mathematical and scientific community: a founding member of Université Paris-Saclay, it works closely with several partners, including CNRS (the French National Research Center).

H.S.H. Prince Albert II of Monaco and Patrice Cellario also visited the IHES library, where they were able to greet David Ruelle, a physicist and permanent professor until 2000 and now professor emeritus at IHES, winner of the Albert 1er de Monaco prize in 1979, awarded by the Academy of Sciences.

Finally, before going to lunch, they met Luc Illusie, a mathematician specializing in algebraic geometry, who was on site for the conference organized in his honor on the occasion of his 80th birthday (81st in fact due to the pandemic!) from 8 to 11 June. Luc Illusie is a precious and faithful member of the Institute’s community: he attended the famous A. Grothendieck’s Seminar during IHES’ first years.

After having had lunch at the Institute’s cafeteria, H.S.H. Prince Albert II of Monaco and Patrice Cellario went to the Marilyn and James Simons Conference Center, where Thibault Damour, a physicist and permanent professor at IHES, gave a talk on gravitational waves. A good opportunity to get a sense of the scientific progress made since Albert Einstein’s first scientific work on this topic, with the most recent observational breakthroughs and their theoretical basis.

A virtual conference in honor of Luc Illusie was held from 7 to 11 June 2021. On this occasion, the following speakers gave talks:

Ahmed Abbes, Vladimir Berkovich, Bhargav Bhatt, Kęstutis Česnavičius, Miaofen Chen, Hélène Esnault, Ofer Gabber, Yongquan Hu, Nicholas Katz, Kazuya Kato, Gérard Laumon, Akhil Mathew, Sophie Morel, Ngô Bảo Châu, Arthur Ogus, Martin Olsson, Takeshi Saito, Yunqing Tang, Michael Temkin, Yichao Tian, et Cong Xue.

The programme [with a timetable centered on TU+2] is available at the following address as well as a registration form you will have to complete to receive the connexion link:

https://server.mcm.ac.cn/~zheng/LI/

Watch the videos of the conference:

As every year, IHES was delighted to host the Statistics & Computer Science Day for Data Science at Paris-Saclay on 5 February 2021. Due to the current health context, the conference was held entirely on video-conference, via Zoom.

Organized by Thanh Mai Pham Ngoc (LMO) and Charles Soussen (L2S), the aim of this statistical and computer science day is to bring together mathematicians and computer scientists around some talks on recent results from statistics and machine learning. Various topics in machine learning, optimization, deep learning, or optimal transport will be presented.

Invited speakers were: Guillaume Charpiat (LRI), Lenaïc Chizat (LMO), Emilie Chouzenoux (CVN), Agnès Desolneux (Centre Borelli), Gaël Richard (Télécom Paris) and Gaël Varoquaux (INRIA Parietal).

Information and registration: on the conference webpage.

Announcement provided by the Maxwell Institute:

The Atiyah Lecture, to commemorate Sir Michael Atiyah (1929-2019) and delivered by a distinguished mathematician who has provided a service to the international mathematical community, is part of the series of distinguished annual lectures run by The Maxwell Institute.

First of the Maxwell Institute’s Atiyah Lectures was given on 11 January 2021 at 15.00-16.00 (GMT)

“We are privileged to have Professor Jean-Pierre Bourguignon as our inaugural Atiyah lecturer. Professor Bourguignon is a distinguished differential geometer who served as director of the IHES, president of the Société Mathématique de France, president of the European Mathematical Society, and most recently president of the European Research Council.”

The Atiyah Lecture was only held via Zoom (Meeting ID: 834 0835 9124 – Mdp: IAL).

The title “What is a Spinor?” is the title of the lecture given by Sir Michael Atiyah in September 2013 at IHES on the occasion of the farewell conference for the retirement of Professor Bourguignon as director.

 

More information:

• Web page for the lecture at The Maxwell Institute
• Web page for the lecture at the ICMS
• Title and abstract of the lecture

Watch the lecture online.

The friendship between IHES and the United States has been a privileged one since the Institute’s early days. Now more than twenty years ago, Friends of IHES was born to honor and strengthen the relationship between IHES and American scientists, partners and donors.

Such a relationship has been reinforced through regular meetings and events that normally take place throughout the year but have mostly been canceled in 2020 due to the restrictions on traveling and gatherings imposed by the current pandemic.

This year instead, Friends of IHES and IHES invited their whole network to take “A Glimpse into the Institut des Hautes Etudes Scientifiques”, an online event held in the presence of Marilyn and Jim Simons, key sponsors for IHES, Michael R. Douglas, president and chairman of Friends of IHES, and Emmanuel Ullmo, director of IHES. The event was introduced by the French Ambassador to the US, Philippe Etienne.

The event startedwith the premiere of “IHES, a Scientific Paradise Born of Franco-American Friendship”, a short movie taking the audience through some of the key milestones that have marked the history of the Institute, with a special emphasis on the relationship with the United States and the support of major donors.

Later on, Slava Rychkov, permanent professor at IHES, introduced the audience to one of the most fascinating phenomena observed throughout physics, the emergence of universality, in a talk titled “Universality in Physics”, followed by Q&A.

Watch the videos of “A Glimpse into IHES”

Watch the introduction to the event:

On December 16^th, 2020, Prof. Robert Penner, René Thom Chair at IHES, will host the conference SciTech Central COVID-19, the 11^th International Virtual Seminar on COVID-19 Part II. It will be a one-day seminar featuring academics, researchers, scientists, students, faculty members, healthcare executives, and doctors who will share their perspective and reflections on the impact of COVID-19 on our lives. The topics discussed will range from treatment and healthcare to the economic repercussions of the pandemic.

 

Robert Penner’s welcome message to the conference:

“With the advent of mRNA vaccines for covid, we have entered a new age of antiviral technology, and it comes not a moment too soon. In its impact on human health and society as a consequence, I believe this will be as profound for our species as was the development of antibiotics. Let us hope this quickly and resolutely is a turning point in our fight against covid and more generally against the countless other viral diseases which threaten humanity. These aspects of vaccinology are among the many timely topics across the health sciences, biomedicine, and social repercussions of covid to be presented in this SciTech Central COVID-19 Virtual Conference.”

Visit the conference webpage, to learn more and register

Learn more about the 11^th International Virtual Seminar on COVID-19 Part II

Watch Robert Penner’s talk premier:

——–  IMPORTANT INFORMATION  ——–

Due to the evolution of the health situation related to the Coronavirus epidemic, the conference was finally given totally online. Find below the videos of the conference.

 

A conference on “Algebraic Structures in Perturbative Quantum Field Theory” was organized by Erik Panzer (University of Oxford) and Karen Yeats (University of Waterloo) at IHES. Organized in honor of the 60th birthday of Dirk Kreimer, the conference was held from 16 to 20 November 2020 online via Zoom.

Perturbative Quantum Field Theory

Perturbative quantum field theory is essential for precision calculations of observables measured in experiments like the LHC, and therefore it is crucial for our understanding of the physics of the universe. At the same time, it is an extremely rich source of connections to a wide range of active research areas in mathematics. For example, Feynman integrals give rise to interesting motives and periods in algebraic geometry, their renormalization rests on combinatorial Hopf algebras underlying Feynman graphs, and further relations to noncommutative geometry and the moduli space of tropical curves and outer space have also been discovered.

Besides, this growing program keeps expanding in both breadth and depth, and exciting young researchers are entering the field. Now is an opportune time to bring together scientists working on all related aspects, to review old and new connections, and to advance the state of the art. Lectures by established scientists will be accompanied by talks from young researchers, including a session dedicated to present and discuss open problems.

Dirk Kreimer, specialist of perturbative quantum field theory

Close collaborations between mathematicians and physicists have been absolutely key for this kind of research, and many were initiated by Dirk Kreimer. Throughout his career, he made substantial contributions across these topics and led students and collaborators to the profound mathematical structures in perturbative quantum field theory that we are aware of today. Dirk Kreimer spent a particularly productive time at the IHES, and it is an honor that this workshop takes place in its inspiring and interdisciplinary environment.

Invited speakers at the Algebraic Structures Conference are:

• Ali Assem Mahmoud (University of Waterloo),
• Marc Bellon (LPTHE – Sorbonne Université),
• Marko Berghoff (Humboldt-Universität),
• Spencer Bloch (University of Chicago), 
• Johannes Blümlein (DESY Zeuthen), 
• Michael Borinsky (Nikhef),
• David Broadhurst (The Open University), 
• Francis Brown (University of Oxford),
• Yvain Bruned (University of Edinburgh),
• Alain Connes (IHES & Collège de France),
• Andrei Davydychev (Moscow State University),
• Gérald Dunne (University of Connecticut),
• Kurusch Ebrahimi-Fard (NTNU Trondheim), 
• Loïc Foissy (Université du Littoral Côte d’Opale),
• Hadleigh Frost (University of Oxford),
• John Gracey (University of Liverpool), 
• Martin Hairer (Imperial College London),
• Alexander Hock (Westfälische Wilhelms-Universität Münster),
• Ralph Kaufmann (Purdue University), 
• Thomas Krajewski (CPT Aix-Marseille), 
• Dominique Manchon (CNRS & Université Clermont-Auvergne),
• Lukas NABERGALL (University of Waterloo),
• Sylvie Paycha (Institut für Mathematik Potsdam),
• Olivier Schnetz (FAU Erlangen-Nürnberg), 
• Christian Schubert (Universidad Michoacana de San Nicolas de Hidalgo),
• Matt Szczesny (Boston University), 
• Walter van Suijlekom (Radboud Universiteit Nijmegen), 
• Karen Vogtmann (University of Warwick),
• Raimar Wulkenhaar (Westfälische Wilhelms-Universität Münster).

For more information, please visit the conference webpage.

IHES and the organisers of the Beijing-Paris-Tokyo Arithmetic Geometry Seminar stand in solidarity with their black colleagues as well as all discriminated communities in the USA and around the world, in the fight against the plague of systemic racism.

In response to the call launched by #ShutDownAcademia, #ShutDownStem and #Strike4BlackLives movements, and with the agreement of the speaker, Christophe Breuil’s lecture has been moved from Wednesday June 10 to Wednesday June 17 at 10:30 am (Paris).

The lecture will be given by webinar. If you have not yet registered, you can do so by filling in the form here before June 16.

The abstract of the lecture is available here:

http://www.ihes.fr/~abbes/SGA/breuil.html

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:

To mark the beginning of a new academic year, the Fondation Mathématique Jacques Hadamard (FMJH) organises a 3-day start of the year for M1 and M2 students of the Mathematical and Applications Master’s degree at Université Paris-Saclay.

From September 4 to 6, students gather at IHES to interact and discuss around lectures, mini-courses and informal discussions, This is also an opportunity for them to get an overview of the IHES’ research activity.

Institutions participating in this 3-day event are: Paris-Sud University, École polytechnique, University of Versailles St. Quentin, ENS Paris-Saclay, Évry-Val-d’Essonne University, ENSTA and CentraleSupélec.

As one of the temples of mathematics, IHES is happy to welcome the FMJH for the 9th time on this occasion.

Find the programme of these days and register on the FMJH website.