Indico Feed [I.H.E.S]https://indico.math.cnrs.fr/category/57/events.atom2019-07-08T06:30:00ZPyAtomNOKIA-IHES Workshophttps://indico.math.cnrs.fr/event/3902/2018-10-02T07:30:00Z<p>This first joint workshop marks the donation between Nokia corporation and the Institut des Hautes Etudes Scientifiques. To celebrate this event we will have two excellent talks which will indirectly reminisce the riches heures of the Bell Laboratories (now Bell Labs part of Nokia corporate) which has now a strong settlement in Paris Saclay campus. Nokia Bell Labs is among the largest and also the oldest private research laboratory in the world and maybe the only one delivering a continuous stream of impressive scientific discoveries and theoretical contributions since one century.<br />
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The first talk will be by professor <strong>Alain Aspect</strong> of Institut d’Optique. Prof Aspect is wordwide known as the physicist who has built the first experimental confirmation of photon quantum entanglement theory. His contribution solved the famous Einstein Podolski Rosen paradox and led to new major perspectives in telecommunication and encryption. This is a way to look back on the major contributions of Bell Labs in quantum technology such as the transistor invented in 1948, and to look forward to quantum computing and communication.<br />
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The second talk will be by professor <strong>Sergio Verdu</strong> of Princeton University. Prof Verdu is the recipient of the Shannon Award in 2007 for his seminal contributions on information theory, in particular in data compression and transmission optimization when time and capacity are critical. Of course his talk will reminisce the history of the Information Theory, formulated in 1948 by Claude Shannon in Bell Labs, but his contributions bring a bridge toward the coming of the new generations of high performance wireless communications.</p>
<p>Organisateurs : Philippe JACQUET (Nokia - FR/Paris-Saclay), Emmanuel ULLMO (IHES)</p>
<p><img src="https://indico.math.cnrs.fr/event/3902/attachments/2179/2502/Nokia-Logo.png" style="height:111px; width:264px" /></p>From Classical Gravity to Quantum Amplitudeshttps://indico.math.cnrs.fr/event/3864/2018-10-05T08:00:00Z<div class="field-items">
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<p>The recent observation of gravitational wave signals from inspiralling and coalescing binary black holes has been significantly helped, from the theoretical side, by the availability of analytical results on the motion and gravitational radiation of binary systems.</p>
<p>The course will deal with the Effective One-Body (EOB) theory of the motion and radiation of binary systems, and explain the links between this formalism and various classical and quantum approaches to gravitationally interacting two-body systems, from traditional post-Newtonian computations of the effective two-body action to quantum gravitational scattering amplitudes.</p>
<p>The following analytical techniques will be reviewed ab initio:</p>
<ol>
<li>Matched Asymptotic Expansions approach to the motion of black holes and neutron stars;</li>
<li>post-Newtonian theory of the motion of point particles;</li>
<li>Multipolar post-Minkowskian theory of the gravitational radiation of general sources;</li>
<li>Effective One-Body (EOB) theory of the motion and radiation of binary systems.</li>
</ol>
<p>The EOB formalism was initially based on a resummation of post-Newtonian-expanded results. The post-Newtonian approach assumes small gravitational potentials and small velocities, and loses its validity during the last orbits before the merger of black holes. The resummed EOB approach was able to extend the validity of the post-Newtonian description of the motion and radiation of binary black holes to the strong-field, high-velocity regime reached during the last orbits, and the merger. EOB theory initially used a dictionary to translate post-Newtonian-expanded results on (slow-motion) bound states of gravitationally interacting binary systems into the (resummed) Hamiltonian of a particle moving in an effective external gravitational field.</p>
<p>The second part of the course will present the recent extension of EOB theory to the description of (classical) scattering states within the post-Minkowskian approach which does not assume that velocities are small. This led to new insights in the high-energy limit of gravitational scattering and opened the way to transcribe quantum gravitational scattering amplitudes into their EOB Hamiltonian description. For instance, some two-loop ultra high-energy quantum scattering results of Amati, Ciafaloni and Veneziano could be transcribed into an improved knowledge of the high-energy limit of the classical gravitational interaction of two black holes. This leads also to interesting predictions about a linear-Regge-trajectory behavior of high-angular-momenta, high-energy circular orbits.</p>
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</div>From Classical Gravity to Quantum Amplitudeshttps://indico.math.cnrs.fr/event/3865/2018-10-12T08:00:00Z<div class="field-items">
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<p>The recent observation of gravitational wave signals from inspiralling and coalescing binary black holes has been significantly helped, from the theoretical side, by the availability of analytical results on the motion and gravitational radiation of binary systems.</p>
<p>The course will deal with the Effective One-Body (EOB) theory of the motion and radiation of binary systems, and explain the links between this formalism and various classical and quantum approaches to gravitationally interacting two-body systems, from traditional post-Newtonian computations of the effective two-body action to quantum gravitational scattering amplitudes.</p>
<p>The following analytical techniques will be reviewed ab initio:</p>
<ol>
<li>Matched Asymptotic Expansions approach to the motion of black holes and neutron stars;</li>
<li>post-Newtonian theory of the motion of point particles;</li>
<li>Multipolar post-Minkowskian theory of the gravitational radiation of general sources;</li>
<li>Effective One-Body (EOB) theory of the motion and radiation of binary systems.</li>
</ol>
<p>The EOB formalism was initially based on a resummation of post-Newtonian-expanded results. The post-Newtonian approach assumes small gravitational potentials and small velocities, and loses its validity during the last orbits before the merger of black holes. The resummed EOB approach was able to extend the validity of the post-Newtonian description of the motion and radiation of binary black holes to the strong-field, high-velocity regime reached during the last orbits, and the merger. EOB theory initially used a dictionary to translate post-Newtonian-expanded results on (slow-motion) bound states of gravitationally interacting binary systems into the (resummed) Hamiltonian of a particle moving in an effective external gravitational field.</p>
<p>The second part of the course will present the recent extension of EOB theory to the description of (classical) scattering states within the post-Minkowskian approach which does not assume that velocities are small. This led to new insights in the high-energy limit of gravitational scattering and opened the way to transcribe quantum gravitational scattering amplitudes into their EOB Hamiltonian description. For instance, some two-loop ultra high-energy quantum scattering results of Amati, Ciafaloni and Veneziano could be transcribed into an improved knowledge of the high-energy limit of the classical gravitational interaction of two black holes. This leads also to interesting predictions about a linear-Regge-trajectory behavior of high-angular-momenta, high-energy circular orbits.</p>
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</div>Google matrix: fundamentals, applications and beyondhttps://indico.math.cnrs.fr/event/3475/2018-10-15T12:00:00Z<h1><img alt="" src="https://indico.math.cnrs.fr/event/3475/material/3/0.jpg" /></h1>
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<p>The workshop will address fundamental features that determine the efficiency and control of information flow on directed networks,information retrieval, including also such fundamental properties of Google matrix as the fractal Weyl law, Anderson localization transitionfor Google matrix eigenstates.</p>
<p>The highlights and future developments of this research fieldwill be analyzed 20 years after the seminal article of Brin and Page (1998).</p>
<p>*-Keywords: Markov chains, complex networks, Google matrix, information and financial flows, Wikipedia and cancer networks, recommender systems</p>
<p><strong>Organisers:</strong></p>
<p> Andras Benczur (MTA SZTAKI Budapest)<br />
Dima Shepelyansky (CNRS-Univ. Paul Sabatier, Toulouse)<br />
Emmanuel Ullmo (IHES)</p>
<p><strong>Scientific Advisory Board:</strong></p>
<p> Andras Benczur,<br />
Misha Gromov (IHES)<br />
Maxim Kontsevich (IHES)<br />
Dima Shepelyansky</p>
<p><strong>List of speakers includes:</strong></p>
<p> Paolo BOLDI (Universita di Milano, IT)<br />
Jean-Philippe BOUCHAUD (CFM, Paris, FR)<br />
Sergey DOROGOVTSEV (University of Aveiro, PT)<br />
Leonardo ERMANN (Comisión Nacional de Energía Atómica, AR)<br />
Klaus FRAHM (Université de Toulouse, FR)<br />
Katia JAFFRES-RUNSER (IRIT, INPT-ENSEEIHT, Toulouse, FR)<br />
Ravi KUMAR (Google CA, USA)<br />
Jose LAGES (Institut UTINAM, Besançon, FR)<br />
Yann LECUN (Facebook AI Research, US)<br />
Matteo MARSILI (ICTP Trieste, IT)<br />
Stéphane NONNENMACHER (Université Paris-Sud, FR)<br />
Robert PALOVICS (Hungarian Academy of Sciences, HU)<br />
Lior ROKACH (Ben-Gurion University of the Negev, IL)<br />
Jean-Jacques SLOTINE (MIT, US)<br />
Andrew TOMKINS (Google CA, USA)<br />
Piet VAN MIEGHEM (Delft Univ, NL)<br />
Andrey ZINOVYEV (Institut Curie, FR)</p>
<p><img alt="Logos" src="https://indico.math.cnrs.fr/event/3475/material/1/0.jpg" style="height:77px; width:340px" /></p>From Classical Gravity to Quantum Amplitudeshttps://indico.math.cnrs.fr/event/3866/2018-10-19T08:00:00Z<div class="field-items">
<div class="field-item even">
<div class="tex2jax">
<p>The recent observation of gravitational wave signals from inspiralling and coalescing binary black holes has been significantly helped, from the theoretical side, by the availability of analytical results on the motion and gravitational radiation of binary systems.</p>
<p>The course will deal with the Effective One-Body (EOB) theory of the motion and radiation of binary systems, and explain the links between this formalism and various classical and quantum approaches to gravitationally interacting two-body systems, from traditional post-Newtonian computations of the effective two-body action to quantum gravitational scattering amplitudes.</p>
<p>The following analytical techniques will be reviewed ab initio:</p>
<ol>
<li>Matched Asymptotic Expansions approach to the motion of black holes and neutron stars;</li>
<li>post-Newtonian theory of the motion of point particles;</li>
<li>Multipolar post-Minkowskian theory of the gravitational radiation of general sources;</li>
<li>Effective One-Body (EOB) theory of the motion and radiation of binary systems.</li>
</ol>
<p>The EOB formalism was initially based on a resummation of post-Newtonian-expanded results. The post-Newtonian approach assumes small gravitational potentials and small velocities, and loses its validity during the last orbits before the merger of black holes. The resummed EOB approach was able to extend the validity of the post-Newtonian description of the motion and radiation of binary black holes to the strong-field, high-velocity regime reached during the last orbits, and the merger. EOB theory initially used a dictionary to translate post-Newtonian-expanded results on (slow-motion) bound states of gravitationally interacting binary systems into the (resummed) Hamiltonian of a particle moving in an effective external gravitational field.</p>
<p>The second part of the course will present the recent extension of EOB theory to the description of (classical) scattering states within the post-Minkowskian approach which does not assume that velocities are small. This led to new insights in the high-energy limit of gravitational scattering and opened the way to transcribe quantum gravitational scattering amplitudes into their EOB Hamiltonian description. For instance, some two-loop ultra high-energy quantum scattering results of Amati, Ciafaloni and Veneziano could be transcribed into an improved knowledge of the high-energy limit of the classical gravitational interaction of two black holes. This leads also to interesting predictions about a linear-Regge-trajectory behavior of high-angular-momenta, high-energy circular orbits.</p>
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</div>From Classical Gravity to Quantum Amplitudeshttps://indico.math.cnrs.fr/event/3867/2018-10-19T12:15:00Z<div class="field-items">
<div class="field-item even">
<div class="tex2jax">
<p>The recent observation of gravitational wave signals from inspiralling and coalescing binary black holes has been significantly helped, from the theoretical side, by the availability of analytical results on the motion and gravitational radiation of binary systems.</p>
<p>The course will deal with the Effective One-Body (EOB) theory of the motion and radiation of binary systems, and explain the links between this formalism and various classical and quantum approaches to gravitationally interacting two-body systems, from traditional post-Newtonian computations of the effective two-body action to quantum gravitational scattering amplitudes.</p>
<p>The following analytical techniques will be reviewed ab initio:</p>
<ol>
<li>Matched Asymptotic Expansions approach to the motion of black holes and neutron stars;</li>
<li>post-Newtonian theory of the motion of point particles;</li>
<li>Multipolar post-Minkowskian theory of the gravitational radiation of general sources;</li>
<li>Effective One-Body (EOB) theory of the motion and radiation of binary systems.</li>
</ol>
<p>The EOB formalism was initially based on a resummation of post-Newtonian-expanded results. The post-Newtonian approach assumes small gravitational potentials and small velocities, and loses its validity during the last orbits before the merger of black holes. The resummed EOB approach was able to extend the validity of the post-Newtonian description of the motion and radiation of binary black holes to the strong-field, high-velocity regime reached during the last orbits, and the merger. EOB theory initially used a dictionary to translate post-Newtonian-expanded results on (slow-motion) bound states of gravitationally interacting binary systems into the (resummed) Hamiltonian of a particle moving in an effective external gravitational field.</p>
<p>The second part of the course will present the recent extension of EOB theory to the description of (classical) scattering states within the post-Minkowskian approach which does not assume that velocities are small. This led to new insights in the high-energy limit of gravitational scattering and opened the way to transcribe quantum gravitational scattering amplitudes into their EOB Hamiltonian description. For instance, some two-loop ultra high-energy quantum scattering results of Amati, Ciafaloni and Veneziano could be transcribed into an improved knowledge of the high-energy limit of the classical gravitational interaction of two black holes. This leads also to interesting predictions about a linear-Regge-trajectory behavior of high-angular-momenta, high-energy circular orbits.</p>
</div>
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</div>Higher Structures in Holomorphic and Topological Field Theoryhttps://indico.math.cnrs.fr/event/3885/2019-01-14T08:00:00Z<p>As part of the <strong>European Research Council Starting Grant programme "Quantum Algebraic Structures in Field Theories" (QUASIFT)</strong> activities, this conference aims to unite physicists and mathematicians working on non-local aspects and higher structures in quantum field theories. Through lectures and informal discussion we will further the productive dialogue between experts studying the application of physical concepts in algebraic geometry and homotopy theory, and the appearance of novel algebraic structures in theoretical physics.</p>
<p>Topics of discussion will include structures associated to line and surface operators, boundary conditions and defects, moduli spaces of vacua, the cobordism hypothesis, factorization homology, and the occurrence of E_n, P_n, chiral and other higher structured algebras</p>
<p><img alt="" src="https://indico.math.cnrs.fr/event/3885/images/1012-fact_mult_fig.jpg" style="height:295px; width:683px" /></p>
<p><strong>List of speakers:</strong></p>
<p><strong>AYALA David</strong> <em>(University of Montana)</em><br />
<strong>BRAVERMAN Alexander</strong> <em>(University of Toronto)</em><br />
<strong>CALAQUE Damien</strong> <em>(Université de Montpellier)</em><br />
<strong>CLIFF Emily</strong> <em>(University of Illinois)</em><br />
<strong>GONCHAROV Alexander</strong> <em>(Yale University</em><br />
<strong>GWILLIAM Owen</strong> <em>(University of Massachusetts)</em><br />
<strong>HIBURN Justin</strong> <em>(U Penn)</em><br />
<strong>HOLLANDS Lotte</strong> <em>(Heriot-Watt University)</em><br />
<strong>JORDAN David</strong> <em>(University of Edinburgh)</em><br />
<strong>KAPUSTIN Anton</strong> <em>(Caltech)</em><br />
<strong>KOROTEEV Peter</strong> <em>(University of California)</em><br />
<strong>NEKRASOV Nikita</strong> <em>(SCGP, Stony Brook)</em><br />
<strong>RAPČÁK Miroslav</strong> <em>(Perimeter Institute)</em><br />
<strong>REN Jie</strong> <em>(IHES)</em><br />
<strong>SAFRONOV Pavel</strong> <em>(University of Zurich)</em><br />
<strong>SCHEIMBAUER Claudia</strong> <em>(Oxford University)</em><br />
<strong>WILLIAMS Brian</strong> <em>(Northeastern University)</em><br />
<strong>YAGI Junya</strong> <em>(University of Warsaw)</em><br />
<strong>YOO Philsang</strong> <em>(Yale University)</em></p>
<p> </p>
<p><strong>Organisers:</strong></p>
<p><strong>ELLIOTT Christopher</strong><em>(IHES)</em><br />
<strong>PESTUN Vasily</strong><em>(IHES)</em></p>
<p> </p>
<p> </p>
<p><img alt="logo ERC" src="https://indico.math.cnrs.fr/event/2833/material/0/0.jpg" style="height:96px; margin:auto; width:100px" /></p>
<p><span>With the support of the European Research Council</span></p>
<p> </p>Aspects of Geometric Group Theoryhttps://indico.math.cnrs.fr/event/3784/2019-07-08T06:30:00Z<p><img alt="" src="https://indico.math.cnrs.fr/event/3026/material/1/0.jpg" /></p>
<p><strong>Organizing/Scientific Committee:</strong> Emmanuel Breuillard (Univ. Paris-Sud), Richard Canary (Univ. Michigan), Indira Chatterji (Univ. Nice-Sophia Antipolis), Fanny Kassel (CNRS-IHES)</p>
<p>The Summer school on "Aspects of Geometric Group Theory" will be held at the Institut des Hautes Etudes Scientifiques (IHES) from 8 to 19 July 2019. IHES is located in Bures-sur-Yvette, south of Paris (40 minutes by train from Paris).</p>
<p>This school is open to everybody but intended primarily for young participants, including PhD students and postdoctoral fellows.</p>
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<p>A group is a mathematical object encoding natural notions of symmetries and transformations. Geometric group theory is an area in mathematics devoted to the study of discrete groups by exploring connections between algebraic properties of such groups and topological and geometric properties of spaces on which these groups act.</p>
<p>As a distinct area, geometric group theory is relatively new, and became an identifiable branch of mathematics in the early 1990s. Geometric group theory closely interacts with low-dimensional topology, hyperbolic geometry, Lie groups and homogeneous spaces, algebraic topology, computational group theory, and differential geometry. There are also substantial connections with complexity theory, mathematical logic, dynamical systems, probability theory, K-theory, and other areas of mathematics.<br />
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Nowadays, geometric group theory is a very active and competitive area of research, as shown by the <a href="http://web.math.ucsb.edu/%7Ejon.mccammond/geogrouptheory/conferences.html">many conferences in the field</a> but also several special programs such as an <a href="https://sites.google.com/site/geowalks2014/">IHP program in 2014</a>, a jumbo <a href="http://www.msri.org/programs/278">MSRI program in 2016</a> and a program at the <a href="https://www.newton.ac.uk/event/npc"> Newton Institute in 2017</a> to name a few.</p>
<p>We will choose a few important trends in geometric group theory and teach those to graduate students across mathematical fields, so that young people in several areas of mathematics such as algebra, geometry, dynamics, or topology have some basics to either understand a few problems in geometric group theory, or use geometric group theory methods in their respective fields. Geometric group theory is a very broad area, and we will mainly focus on geometric aspects.</p>
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<p><strong>This is an IHES Summer School, organized in partnership with the <a href="https://www.claymath.org">Clay Mathematical Institute</a>, and the support of the <a href="https://www.societegenerale.fr">Société Générale</a>, the <a href="https://www.fondation-hadamard.fr">FMJH</a>, the <a href="http://iuf.amue.fr" target="_blank">IUF</a>, the <a href="http://math.unice.fr/%7Eindira/GAMME.html">ANR GAMME</a>, the project <a href="http://math.unice.fr/%7Elabourie/LouisD/index.html">Jeunes Géomètres</a> and the <a href="https://erc.europa.eu"> ERC</a>.</strong></p>
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<p><strong>INVITED SPEAKERS:</strong></p>
<p>So far the following people have agreed to give a mini-course:</p>
<ul>
<li>Yves Benoist</li>
<li>Kai-Uwe Bux</li>
<li>Ruth Charney</li>
<li>François Dahmani</li>
<li>Pallavi Dani</li>
<li>Anna Erschler</li>
<li>François Guéritaud</li>
<li>Frédéric Haglund</li>
<li>Kathryn Mann</li>
<li>Yair Minsky</li>
<li>Karen Vogtmann</li>
<li>Genevieve Walsh</li>
<li>Anna Wienhard</li>
</ul>
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<p> </p>
<p> </p>