|
|
|
The SEMPARIS seminar webserver hosts annoucements of all seminars taking place in Paris area, in all topics of physics, mathematics and computer science. It allows registered users to receive a selection of announcements by email on a daily or weekly basis, and offers the possibility to archive PDF or Powerpoint files, making it available to the scientific community. [ More information ]
| [Previous 30 ] | Upcoming Seminars | [Next 30 ] |
| [ scheduler view ] | ||
| Wednesday 12 February 2025, 13:30 at IHP, Amphi Choquet-Bruhat (batiment Perrin) | SEED (Seed Seminar of Mathematics and Physics) | math-ph |
|
|
|
|
| Abstract: | Hamiltonian paths are self-avoiding random walks that visit all sites of a given lattice. We consider various configuration exponents of Hamiltonian walks drawn on random planar maps. Estimates from exact enumerations are compared with predictions based on the Knizhnik-Polyakov-Zamolodchikov (KPZ) relations, as applied to exponents on the regular hexagonal lattice. Astonishingly, when the maps are bipartite, a naive use of KPZ does not reproduce all the measured exponents, but an Ansatz may possibly account for the observed discrepancies. We further study Hamiltonian cycles on various families of bipartite planar maps, which fall into two universality classes, with respective central charges c = -1 or c = -2. The first group comprises maps of fixed vertex valency p larger than 3, whereas the second group involves maps with mixed vertex valencies, as well as a so-called rigid case. For each class, a universal configuration exponent and a novel critical exponent associated with long-distance contacts along a Hamiltonian cycle are predicted from KPZ and the corresponding exponent on regular (hexagonal or square) lattices. This time, the KPZ predictions are numerically confirmed by exact enumeration results for p-regular maps, with p = 3, 4, 5, 6, 7, and for maps with mixed valencies (2,3) and (2,4). The scaling limit of fully-packed systems thus poses intriguing unresolved questions from both the Liouville Quantum Gravity and the Schramm-Loewner Evolution perspectives. Based on joint works with Ph. Di Francesco, O. Golinelli and E. Guitter. | |
| Wednesday 12 February 2025, 15:00 at IHP, Amphi Choquet-Bruhat (batiment Perrin) | SEED (Seed Seminar of Mathematics and Physics) | math-ph |
|
|
|
|
| Abstract: | We construct the continuum analogue of the chemical distance metric in lattice models such as percolation. The chemical distance metric is the graph distance induced by the percolation clusters. It is known that for critical percolation, the lengths have non-trivial scaling behaviour, however it is very difficult to find the exact scaling exponent. (This is one of the questions from Schramm's ICM 2006 article that remains unsolved.) In a joint work with Valeria Ambrosio and Jason Miller, we construct a chemical distance metric on the CLE gasket for each $\kappa\in]4,8[$. We show that it is unique metric that is geodesic, Markovian, and conformally covariant. The characterisation is reminiscent of the LQG metric, but our objects behave very differently, and hence our techniques also differ significantly from those used in LQG. For $\kappa=6$, we conjecture that our random metric space is the scaling limit of critical percolation. | |
| Wednesday 12 February 2025, 16:15 at IHP, Amphi Choquet-Bruhat (batiment Perrin) | SEED (Seed Seminar of Mathematics and Physics) | math-ph |
|
|
|
|
| Abstract: | In this talk, I will consider the interface separating +1 and -1 spins in the critical planar Ising model with Dobrushin boundary conditions perturbed by an external magnetic field. I will prove that this interface has a scaling limit. This result holds when the Ising model is defined on a bounded and simply connected subgraph of $\delta\mathbb{Z}^2$, with $\delta > 0$. I will show that if the scaling of the external field is of order $\delta^{15/8}$, then, as $\delta \to 0$, the interface converges in law to a random curve whose law is conformally covariant and absolutely continuous with respect to $\text{SLE}_3$. This limiting law is a massive version of $\text{SLE}_3$ in the sense of Makarov and Smirnov and I will give an explicit expression for its Radon-Nikodym derivative with respect to $\text{SLE}_3$. I will also prove that if the scaling of the external field is of order $\delta^{15/8}g(\delta)$ with $g(\delta) \to 0$, then the interface converges in law to $\text{SLE}_3$. In contrast, I will show that if the scaling of the external field is of order $\delta^{15/8}f(\delta)$ with $f(\delta) \to \infty$, then the interface degenerates to a boundary arc. | |
| Thursday 13 February 2025, 10:00 at IHP, Pierre Grisvard | RENC-THEO (Rencontres Théoriciennes) | hep-th |
|
|
|
|
| Thursday 13 February 2025, 11:00 at
IHES,
Amphithéâtre Léon Motchane ( Séminaire de Géométrie Arithmétique ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | From the 1980s to the 1990s, Jean-Marc Fontaine introduced the theory of (phi, Gamma)-modules to study p-adic Galois representations. They are simpler than p-adic Galois representations, but he showed an equivalence between them. Among p-adic Galois representations, some classes are particularly important in number theory. Main examples are crystalline representations, semi-stable representations and de Rham representations. In this talk, I will explain how we can determine the (phi, Gamma)-modules corresponding to these representations. These results can be seen, in a sense, as generalizations of Wach modules. | |
| Thursday 13 February 2025, 14:00 at LPTMC, campus Jussieu, couloir 12-13, 5ème étage, salle 5-23 | SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée) | cond-mat |
|
|
|
|
| Abstract: | TBA | |
| Tuesday 18 February 2025, 10:30 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The most universal kind of linear algebra is based not on abelian groups, but on homotopy-theoretic objects known as spectra. According to chromatic homotopy theory, one can systematically organize spectra into periodic families. On the other hand, a natural source of spectra is provided by algebraic K-theory, a highly refined cohomological invariant of rings (or schemes, etc). This leads to the subject of this course: the interaction of the chromatic theory with algebraic K-theory. The story begins with classical theorems of Thomason, Mitchell, and Hesselholt-Madsen. Bold generalizations of these theorems were conjectured by Rognes and Ausoni-Rognes, under the umbrella term of "redshift". Several of these conjectures are now theorems due to recent work of many people. Remarkably, this work has applications to "pure" chromatic homotopy theory: Burklund-Hahn-Levy-Schlank used it to settle (in the negative) the "telescope conjecture", the last of Ravenel's conjectures. Lecture 1: Introduction to chromatic homotopy theory. Lecture 2: Descent and "soft redshift". Lecture 3: "Hard redshift", a.k.a. the Lichtenbaum-Quillen property. Lecture 4: The telescope conjecture. | |
| Thursday 20 February 2025, 10:30 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The most universal kind of linear algebra is based not on abelian groups, but on homotopy-theoretic objects known as spectra. According to chromatic homotopy theory, one can systematically organize spectra into periodic families. On the other hand, a natural source of spectra is provided by algebraic K-theory, a highly refined cohomological invariant of rings (or schemes, etc). This leads to the subject of this course: the interaction of the chromatic theory with algebraic K-theory. The story begins with classical theorems of Thomason, Mitchell, and Hesselholt-Madsen. Bold generalizations of these theorems were conjectured by Rognes and Ausoni-Rognes, under the umbrella term of "redshift". Several of these conjectures are now theorems due to recent work of many people. Remarkably, this work has applications to "pure" chromatic homotopy theory: Burklund-Hahn-Levy-Schlank used it to settle (in the negative) the "telescope conjecture", the last of Ravenel's conjectures. Lecture 1: Introduction to chromatic homotopy theory. Lecture 2: Descent and "soft redshift". Lecture 3: "Hard redshift", a.k.a. the Lichtenbaum-Quillen property. Lecture 4: The telescope conjecture. | |
| Thursday 20 February 2025, 11:00 at LPTHE, LPTHE library | SEM-LPTHE (Séminaire du LPTHE) | cond-mat.str-el |
|
|
|
|
| Tuesday 25 February 2025, 10:30 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The most universal kind of linear algebra is based not on abelian groups, but on homotopy-theoretic objects known as spectra. According to chromatic homotopy theory, one can systematically organize spectra into periodic families. On the other hand, a natural source of spectra is provided by algebraic K-theory, a highly refined cohomological invariant of rings (or schemes, etc). This leads to the subject of this course: the interaction of the chromatic theory with algebraic K-theory. The story begins with classical theorems of Thomason, Mitchell, and Hesselholt-Madsen. Bold generalizations of these theorems were conjectured by Rognes and Ausoni-Rognes, under the umbrella term of "redshift". Several of these conjectures are now theorems due to recent work of many people. Remarkably, this work has applications to "pure" chromatic homotopy theory: Burklund-Hahn-Levy-Schlank used it to settle (in the negative) the "telescope conjecture", the last of Ravenel's conjectures. Lecture 1: Introduction to chromatic homotopy theory. Lecture 2: Descent and "soft redshift". Lecture 3: "Hard redshift", a.k.a. the Lichtenbaum-Quillen property. Lecture 4: The telescope conjecture. | |
| Thursday 27 February 2025, 10:30 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The most universal kind of linear algebra is based not on abelian groups, but on homotopy-theoretic objects known as spectra. According to chromatic homotopy theory, one can systematically organize spectra into periodic families. On the other hand, a natural source of spectra is provided by algebraic K-theory, a highly refined cohomological invariant of rings (or schemes, etc). This leads to the subject of this course: the interaction of the chromatic theory with algebraic K-theory. The story begins with classical theorems of Thomason, Mitchell, and Hesselholt-Madsen. Bold generalizations of these theorems were conjectured by Rognes and Ausoni-Rognes, under the umbrella term of "redshift". Several of these conjectures are now theorems due to recent work of many people. Remarkably, this work has applications to "pure" chromatic homotopy theory: Burklund-Hahn-Levy-Schlank used it to settle (in the negative) the "telescope conjecture", the last of Ravenel's conjectures. Lecture 1: Introduction to chromatic homotopy theory. Lecture 2: Descent and "soft redshift". Lecture 3: "Hard redshift", a.k.a. the Lichtenbaum-Quillen property. Lecture 4: The telescope conjecture. | |
| Wednesday 5 March 2025, 14:00 at LPENS, L378 | FORUM-ENS (Forum de Physique Statistique @ ENS) | cond-mat.stat-mech |
|
|
|
|
| Thursday 6 March 2025, 11:00 at LPTHE, bibliothèque du LPTHE, tour 13-14, 4eme étage | SEM-DARBOUX (Séminaire Darboux - physique théorique et mathématiques) | hep-th |
|
|
|
|
| Wednesday 12 March 2025, 13:30 at DPT-PHYS-ENS, salle ConfIV (Département de Physique de l'ENS - 24 rue Lhomond 75005 PARIS) | COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS) | physics |
|
|
|
|
| Abstract: | TBA | |
| Wednesday 19 March 2025, 12:45 at LPENS, 3 rue dUlm (College de France) | FORUM-ENS (Forum de Physique Statistique @ ENS) | cond-mat.stat-mech |
|
|
|
|
| Thursday 27 March 2025, 14:00 at LPTMC, Jussieu, LPTMC seminar room, towers 13-12, 5th floor, room 523 | SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée) | cond-mat |
|
|
|
|
| Abstract: | TBA | |
| Thursday 27 March 2025, 17:00 at UFR-PHYS-SU, Amphi 25 Campus Pierre-et-Marie-Curie, Jussieu | CPMC (Colloquium Pierre et Marie Curie) | astro-ph|cond-mat|gr-qc|hep-ex|hep-lat|hep-ph|hep-th|physics|quant-ph |
|
|
|
|
| Abstract: | TBA | |
| Wednesday 2 April 2025, 13:30 at DPT-PHYS-ENS, salle ConfIV (Département de Physique de l'ENS - 24 rue Lhomond 75005 PARIS) | COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS) | physics |
|
|
|
|
| Abstract: | TBA | |
| Friday 4 April 2025, 14:00 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The key property of linear dispersive flows is that waves with different frequencies travel with different group velocities, which leads to the phenomena of dispersive decay. Nonlinear dispersive flows also allow for interactions of linear waves, and their long time behavior is determined by the balance of linear dispersion on one hand, and nonlinear effects on the other hand. The first goal of these lectures will be to present and motivate a new set of conjectures which aim to describe the global well-posedness and the dispersive properties of solutions in the most difficult case when the nonlinear effects are dominant, assuming only small initial data. This covers many interesting physical models, yet, as recently as a few years ago, there was no clue even as to what one might reasonably expect. The second objective of the lectures will be to describe some very recent results in this direction, in joint work with my collaborator Mihaela Ifrim from University of Wisconsin, Madison. | |
| Monday 7 April 2025, 14:00 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The key property of linear dispersive flows is that waves with different frequencies travel with different group velocities, which leads to the phenomena of dispersive decay. Nonlinear dispersive flows also allow for interactions of linear waves, and their long time behavior is determined by the balance of linear dispersion on one hand, and nonlinear effects on the other hand. The first goal of these lectures will be to present and motivate a new set of conjectures which aim to describe the global well-posedness and the dispersive properties of solutions in the most difficult case when the nonlinear effects are dominant, assuming only small initial data. This covers many interesting physical models, yet, as recently as a few years ago, there was no clue even as to what one might reasonably expect. The second objective of the lectures will be to describe some very recent results in this direction, in joint work with my collaborator Mihaela Ifrim from University of Wisconsin, Madison. | |
| Monday 7 April 2025, 14:00 at LPENS, TBD | LPENS-MDQ (Séminaire Matériaux et Dispositifs Quantiques du LPENS) | cond-mat |
|
|
|
|
| Wednesday 9 April 2025, 14:00 at LPENS, 3 rue dUlm (College de France) | FORUM-ENS (Forum de Physique Statistique @ ENS) | cond-mat.stat-mech |
|
|
|
|
| Wednesday 9 April 2025, 14:00 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The key property of linear dispersive flows is that waves with different frequencies travel with different group velocities, which leads to the phenomena of dispersive decay. Nonlinear dispersive flows also allow for interactions of linear waves, and their long time behavior is determined by the balance of linear dispersion on one hand, and nonlinear effects on the other hand. The first goal of these lectures will be to present and motivate a new set of conjectures which aim to describe the global well-posedness and the dispersive properties of solutions in the most difficult case when the nonlinear effects are dominant, assuming only small initial data. This covers many interesting physical models, yet, as recently as a few years ago, there was no clue even as to what one might reasonably expect. The second objective of the lectures will be to describe some very recent results in this direction, in joint work with my collaborator Mihaela Ifrim from University of Wisconsin, Madison. | |
| Friday 11 April 2025, 14:00 at
IHES,
Amphithéâtre Léon Motchane ( Cours de l'IHES ) | MATH-IHES (TBA) | math |
|
|
|
|
| Abstract: | The key property of linear dispersive flows is that waves with different frequencies travel with different group velocities, which leads to the phenomena of dispersive decay. Nonlinear dispersive flows also allow for interactions of linear waves, and their long time behavior is determined by the balance of linear dispersion on one hand, and nonlinear effects on the other hand. The first goal of these lectures will be to present and motivate a new set of conjectures which aim to describe the global well-posedness and the dispersive properties of solutions in the most difficult case when the nonlinear effects are dominant, assuming only small initial data. This covers many interesting physical models, yet, as recently as a few years ago, there was no clue even as to what one might reasonably expect. The second objective of the lectures will be to describe some very recent results in this direction, in joint work with my collaborator Mihaela Ifrim from University of Wisconsin, Madison. | |
| Wednesday 7 May 2025, 12:45 at LPENS, 3 rue dUlm (College de France) | FORUM-ENS (Forum de Physique Statistique @ ENS) | cond-mat.stat-mech |
|
|
|
|
| Thursday 22 May 2025, 17:00 at UFR-PHYS-SU, Amphi 25 Campus Pierre-et-Marie-Curie, Jussieu | CPMC (Colloquium Pierre et Marie Curie) | astro-ph|cond-mat|gr-qc|hep-ex|hep-lat|hep-ph|hep-th|physics|quant-ph |
|
|
|
|
| Abstract: | TBA | |
| Wednesday 28 May 2025, 13:30 at DPT-PHYS-ENS, salle ConfIV (Département de Physique de l'ENS - 24 rue Lhomond 75005 PARIS) | COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS) | physics |
|
|
|
|
| Abstract: | TBA | |
| Thursday 12 June 2025, 11:00 at LPTHE, bibliothèque du LPTHE, tour 13-14, 4eme étage | SEM-DARBOUX (Séminaire Darboux - physique théorique et mathématiques) | hep-th |
|
|
|
|
| Thursday 19 June 2025, 14:00 at LPTMC, Jussieu, LPTMC seminar room, towers 13-12, 5th floor, room 523 | SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée) | cond-mat |
|
|
|
|
| Monday 23 June 2025, 13:30 at DPT-PHYS-ENS, salle ConfIV (Département de Physique de l'ENS - 24 rue Lhomond 75005 PARIS) | COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS) | physics |
|
|
|
|
| Abstract: | TBA | |
|
PDF Poster |
RSS Thread |
ICal Format
]
|
|
[ English version ] |