Department of Mathematics

Search

Talks in mathematical physics

×

Modal title

Modal content

Please subscribe here if you would you like to be notified about these events via e-mail. Moreover you can also subscribe to the iCal/ics Calender.

Spring Semester 2016

Date / Time Speaker Title Location
* 25 February 2016
14:15-15:15 		Alexander Varchenko
UNC Chapel Hill and MPI Bonn
Details

Talks in Mathematical Physics

Title The B. and M. Shapiro conjecture in real algebraic geometry and Bethe ansatz
Speaker, Affiliation Alexander Varchenko, UNC Chapel Hill and MPI Bonn
Date, Time 25 February 2016, 14:15-15:15
Location HG G 43
Abstract I shall discuss the proof of Shapiro’s conjecture by methods of math physics and representation theory. The Shapiro’s conjecture says the following. If the Wronskian of a set of polynomials has real roots only, then the complex span of this set of polynomials has a basis consisting of polynomials with real coefficients.
The B. and M. Shapiro conjecture in real algebraic geometry and Bethe ansatzread_more
HG G 43
* 25 February 2016
15:30-16:30 		Geoffroy Horel
MPI Bonn
Details

Talks in Mathematical Physics

Title Profinite completion of operads and the absolute Galois group of Q
Speaker, Affiliation Geoffroy Horel, MPI Bonn
Date, Time 25 February 2016, 15:30-16:30
Location HG G 43
Abstract I will first talk about the profinite completion of spaces. This is a construction originally due to Artin and Mazur which approximates a space by truncated spaces with finite homotopy groups. Using a good point-set level model of this construction, one can form the profinite completion of operads in spaces. The main theorem I want to talk about states that the profinite completion of the operad E2 is acted on by the absolute Galois group of Q and that this action is faithful.
Profinite completion of operads and the absolute Galois group of Qread_more
HG G 43
3 March 2016
15:15-16:15 		Zhengwei Liu
Harvard University
Details

Talks in Mathematical Physics

Title New diagrammatic insights in mathematical physics
Speaker, Affiliation Zhengwei Liu, Harvard University
Date, Time 3 March 2016, 15:15-16:15
Location HG G 43
Abstract We interpret some classical concepts in mathematical physics in a diagrammatic way, such as the Fourier transform and reflection positivity. We give one new family of algebras to realize this idea. As an application, we give some diagrammatic models for quantum information, which unite the topological aspect of qudits and their entanglement.
New diagrammatic insights in mathematical physicsread_more
HG G 43
* 10 March 2016
14:15-15:15 		Gabriele Rembado
Université de Paris / Aarhus University
Details

Talks in Mathematical Physics

Title Nonabelian Hodge theory and quantisation of moduli spaces
Speaker, Affiliation Gabriele Rembado, Université de Paris / Aarhus University
Date, Time 10 March 2016, 14:15-15:15
Location HG G 19.1
Abstract In 1965 Narasimhan ans Seshadri proved a theorem relating (degree zero) stable holomorphic vector bundles over a closed Riemann surface to the (irreducible) unitary representations of the fundamental group of that surface. This result has been generalised in several directions, basically spawning a new branch of algebraic geometry. Let's focus on two of them: 1. Pick complex representations of the fundamental group 2. Decorate the curve The former led to the first instance of the nonabelian Hodge correspondence, according to the terminology introduced by Carlos Simpson. The latter brought about the notion of a wild Riemann surface. Both produced many new and interesting moduli spaces to study and try to quantise. The talk will loosely survey those generalisations and give a hint to recent quantisation attempts.
Nonabelian Hodge theory and quantisation of moduli spacesread_more
HG G 19.1
* 15 March 2016
15:00-16:00 		Geoff Schneider
Temple University
Details

Talks in Mathematical Physics

Title Recursive construction of formality quasi-isomorphisms
Speaker, Affiliation Geoff Schneider, Temple University
Date, Time 15 March 2016, 15:00-16:00
Location Y27 H 26
Abstract Formality quasi-isomorphisms Cobar(C) → O are often constructed via transcendental methods, resulting in quasi-isomorphisms defined over extensions of Q. By showing that they can be constructed recursively simply by solving systems of linear equations over Q, in this talk we will show that these formality quasi-isomorphisms can be ”demystified” for a large class of dg-operads, given certain assumptions on H.(O). This result is motivated by applications to deformation quantization, and to computation of the rational homotopy groups of embedding spaces. This talk is based on a paper in preparation joint with V.A. Dolgushev.
Recursive construction of formality quasi-isomorphismsread_more
Y27 H 26
17 March 2016
15:15-16:15 		Javier Fresan
ETH Zurich
Details

Talks in Mathematical Physics

Title Amplitudes and the asymptotic of the height pairing
Speaker, Affiliation Javier Fresan, ETH Zurich
Date, Time 17 March 2016, 15:15-16:15
Location HG G 43
Abstract Given two degree zero divisors with disjoint support on a smooth curve, the height pairing is defined by integrating a differential with residues along the first divisor over a cycle whose boundary is the second one. I will present a joint work with O. Amini, S. Bloch, and J.I. Burgos Gil, in which we study the asymptotic behavior of this quantity as the curve degenerates to a stable marked curve. The main contribution is given by the quotient of the first and the second Symanzik polynomials of the marked dual graph. As an application, we show that the integrand of string amplitudes converges to the integrand of Feynman amplitudes in the low-energy limit.
Amplitudes and the asymptotic of the height pairingread_more
HG G 43
* 5 April 2016
17:00-18:00 		Pedro Boavida de Brito
UC Louvain
Details

Talks in Mathematical Physics

Title Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad I
Speaker, Affiliation Pedro Boavida de Brito, UC Louvain
Date, Time 5 April 2016, 17:00-18:00
Location Y27 H 28
Abstract In this lecture series, I will present some recent advances in the study of spaces of smooth embeddings that have uncovered a strong link to operad theory. A result which illustrates well this relationship says that the space of smooth embeddings with compact support from R^m (Euclidean space) to R^n is closely related to space of (derived) operad maps from the little m-discs operad to the little n-discs operad, when n - m is greater than 2. An important ingredient in proving statements of this type is “manifold calculus”, a calculus of functors due to Goodwillie and Weiss that allows (in good cases) one to approximate a functor in a way reminiscent of the approximation of a function by its Taylor series. The first part of these lectures will be a gentle introduction to manifold calculus.
Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad Iread_more
Y27 H 28
6 April 2016
17:00-18:00 		Pedro Boavida de Brito
UC Louvain
Details

Talks in Mathematical Physics

Title Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad II
Speaker, Affiliation Pedro Boavida de Brito, UC Louvain
Date, Time 6 April 2016, 17:00-18:00
Location Y27 H 28
Abstract In this lecture series, I will present some recent advances in the study of spaces of smooth embeddings that have uncovered a strong link to operad theory. A result which illustrates well this relationship says that the space of smooth embeddings with compact support from R^m (Euclidean space) to R^n is closely related to space of (derived) operad maps from the little m-discs operad to the little n-discs operad, when n - m is greater than 2. An important ingredient in proving statements of this type is “manifold calculus”, a calculus of functors due to Goodwillie and Weiss that allows (in good cases) one to approximate a functor in a way reminiscent of the approximation of a function by its Taylor series. The first part of these lectures will be a gentle introduction to manifold calculus.
Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad IIread_more
Y27 H 28
7 April 2016
15:15-16:00 		Pedro Boavida de Brito
UC Louvain
Details

Talks in Mathematical Physics

Title Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad III
Speaker, Affiliation Pedro Boavida de Brito, UC Louvain
Date, Time 7 April 2016, 15:15-16:00
Location HG G 43
Abstract In this lecture series, I will present some recent advances in the study of spaces of smooth embeddings that have uncovered a strong link to operad theory. A result which illustrates well this relationship says that the space of smooth embeddings with compact support from R^m (Euclidean space) to R^n is closely related to space of (derived) operad maps from the little m-discs operad to the little n-discs operad, when n - m is greater than 2. An important ingredient in proving statements of this type is “manifold calculus”, a calculus of functors due to Goodwillie and Weiss that allows (in good cases) one to approximate a functor in a way reminiscent of the approximation of a function by its Taylor series. The first part of these lectures will be a gentle introduction to manifold calculus.
Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad IIIread_more
HG G 43
8 April 2016
13:45-17:30 		Anton Alekseev
Geneva
Hermann Schulz-Baltes
Erlangen
Mauro Spera
Brescia
Details

Talks in Mathematical Physics

Title Meeting on Geometry and topology in mathematical physics
Speaker, Affiliation Anton Alekseev, Geneva
Hermann Schulz-Baltes, Erlangen
Mauro Spera, Brescia
Date, Time 8 April 2016, 13:45-17:30
Location HG F 26.1
Abstract 1:45 – 2:00 Opening remarks 2:00 – 3:00 Anton Alexeev Integrability in the Horn problem? 3:00 – 4:00 Hermann Schulz-Baldes Topological Insulators: From K-Theory to Physics 4:00 – 4:30 BREAK 4:30 – 5:30 Mauro Spera Geometric construction of unitary Riemann surface braid group representations and generalized Laughlin wave functions
Meeting on Geometry and topology in mathematical physicsread_more
HG F 26.1
8 April 2016
17:00-18:00 		Pedro Boavida de Brito
UC Louvain
Details

Talks in Mathematical Physics

Title Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad IV
Speaker, Affiliation Pedro Boavida de Brito, UC Louvain
Date, Time 8 April 2016, 17:00-18:00
Location Y27 H 28
Abstract In this lecture series, I will present some recent advances in the study of spaces of smooth embeddings that have uncovered a strong link to operad theory. A result which illustrates well this relationship says that the space of smooth embeddings with compact support from R^m (Euclidean space) to R^n is closely related to space of (derived) operad maps from the little m-discs operad to the little n-discs operad, when n - m is greater than 2. An important ingredient in proving statements of this type is “manifold calculus”, a calculus of functors due to Goodwillie and Weiss that allows (in good cases) one to approximate a functor in a way reminiscent of the approximation of a function by its Taylor series. The first part of these lectures will be a gentle introduction to manifold calculus.
Spaces of smooth embeddings, Goodwillie-Weiss calculus and the little discs operad IVread_more
Y27 H 28
14 April 2016
15:15-16:15 		Ricardo Miguel Campos
University of Zurich
Details

Talks in Mathematical Physics

Title A graph model for configuration spaces of points on a manifold
Speaker, Affiliation Ricardo Miguel Campos, University of Zurich
Date, Time 14 April 2016, 15:15-16:15
Location HG G 43
Abstract Given a manifold M, one can study the configuration space of n points on the manifold. These spaces are of interest for different fields of mathematics and despite some apparent simplicity, even their homology is reasonably unknown. Under some conditions on M, its configuration space of points can be compactified so as to admit a right action of the little discs operad. In this talk, I will exhibit a combinatorial model of such configuration spaces that takes into account the additional right module structure. This is joint work with Thomas Willwacher based on arXiv:1604.02043 .
A graph model for configuration spaces of points on a manifoldread_more
HG G 43
28 April 2016
15:15-16:15 		Vasily Pestun
IHES
Details

Talks in Mathematical Physics

Title Quiver W-algebras
Speaker, Affiliation Vasily Pestun, IHES
Date, Time 28 April 2016, 15:15-16:15
Location HG G 43
Abstract In this talk I will show how the geometry of instanton moduli spaces of quiver gauge theories leads naturally to the construction of q-deformed W-algebras of Frenkel and Reshetikhin associated to the same quiver, and, in parallel, to the quantization of the algebraic integrable system of periodic monopoles.
Quiver W-algebrasread_more
HG G 43
12 May 2016
14:15-15:15 		Federico Zerbini
Max Planck Institute for Mathematics, Bonn
Details

Talks in Mathematical Physics

Title Superstring amplitudes and single-valued multiple zeta values
Speaker, Affiliation Federico Zerbini, Max Planck Institute for Mathematics, Bonn
Date, Time 12 May 2016, 14:15-15:15
Location HG G 43
Abstract In this talk we describe a way to algorithmically compute the first coefficients in the Fourier expansion of the functions involved in the closed superstring amplitudes in genus one, making use of a generalization of multiple zeta values called conical sums. The results obtained using this method lead us to conjecture that only single-valued multiple zeta values appear as coefficients of the amplitude. This is consistent with the well understood genus zero case.
Superstring amplitudes and single-valued multiple zeta valuesread_more
HG G 43
19 May 2016
15:15-16:15 		Nils Scheithauer
Universität Darmstadt
Details

Talks in Mathematical Physics

Title Orbifolds
Speaker, Affiliation Nils Scheithauer, Universität Darmstadt
Date, Time 19 May 2016, 15:15-16:15
Location HG G 43
Abstract Vertex algebras give a mathematically rigorous description of conformal field theories. A prominent example is the moonshine module which was used by Borcherds to prove the moonshine conjecture. The moonshine module is an orbifold of the vertex algebra of the Leech lattice by an order 2 automorphism. In this talk we describe a generalisation of this construction to finite cyclic groups acting on holomorphic vertex operator algebras. As an application we construct some new holomorphic vertex operator algebras of central charge 24 as lattice orbifolds.
Orbifoldsread_more
HG G 43
* 23 May 2016
09:30-17:30

Details

Talks in Mathematical Physics

Title Positive reflections, in memory of Robert Schrader
Speaker, Affiliation ,
Date, Time 23 May 2016, 09:30-17:30
Location HG E 3
Abstract www.itp.phys.ethz.ch/robertschrader
Positive reflections, in memory of Robert Schraderread_more
HG E 3
26 May 2016
15:15-16:15 		Peter Samuelson
University of Iowa
Details

Talks in Mathematical Physics

Title The Homfly skein and elliptic Hall algebras
Speaker, Affiliation Peter Samuelson, University of Iowa
Date, Time 26 May 2016, 15:15-16:15
Location HG G 43
Abstract Turaev and Przytycki defined the Homfly skein algebra H to be the space of links in the thickened torus modulo the Homfly skein relations, which come from knot theory. (The product is stacking links.) Burban and Schiffmann defined the 'universal' Hall algebra E of the category Coh(X) of coherent sheaves over an elliptic curve X in finite characteristic. (The product roughly comes from counting extensions in Coh(X).) We show the algebras H and E are isomorphic by giving an explicit description of H. We then discuss the relation to refined polynomials associated to iterated torus knots. (Joint work with H. Morton.)
The Homfly skein and elliptic Hall algebrasread_more
HG G 43
* 3 June 2016
15:15-16:15 		Najib Idrissi
Lille
Details

Talks in Mathematical Physics

Title Swiss-Cheese operad and Drinfeld center
Speaker, Affiliation Najib Idrissi, Lille
Date, Time 3 June 2016, 15:15-16:15
Location HG E 33.5
Abstract Voronov's "Swiss-Cheese" operad governs the action of a little disks algebra on a little intervals algebra. In this talk, I will explain how to obtain models of the fundamental groupoid of the Swiss-Cheese operad: a first model using bicolored braids and whose algebras can be described using Drinfeld centers, and a second (rational) model that involves a Drinfeld associator. We will compare this model to the model deduced from the homology of the Swiss-Cheese operad, the difference being explained by the non-formality of SC.
Swiss-Cheese operad and Drinfeld centerread_more
HG E 33.5

Notes: events marked with an asterisk (*) indicate that the time and/or location are different from the usual time and/or location.

Archive: AS 24 SS 24 AS 23 SS 23 AS 22 SS 22 AS 21 SS 21 AS 20 SS 20 AS 19 SS 19 AS 18 SS 18 AS 17 SS 17 AS 16 SS 16 AS 15 SS 15 AS 14 SS 14 AS 13 SS 13 AS 12 SS 12 AS 11

JavaScript has been disabled in your browser