Date/Time : 08 Sep 2022 15:00
Venue : S17 #04-06 (SR1)
Speaker : Thibaut Vasseur, University of Lille

Abstract:  A periodic Riesz gas is any microscopic thermodynamic limit of Gibbs particle systems on the torus interacting via the Riesz potential of parameter s. We focus on the non-integrable case d − 1 < s < d, where the point process can be described by canonical DLR equations. Our main result ensures, for any dimension and inverse temperature, the existence of a periodic Riesz gas which is not number-rigid. Recall that a point process is said number rigid if the number of points in a bounded Borel set is a function of the point configuration outside the set. As a consequence, we show that this particular Riesz gas satisfies a grand-canonical DLR equation and allows a renormalization of the energy of a point inside an infinite configuration. Based on a joint work with D. Dereudre.

Add to calendar :

Date/Time : 26 Aug 2022 10:00
Venue : S17 #04-04 (SR3)
Speaker : Michele Salvi, University of Tor Vergata

Abstract: Scale-free percolation is a spatial inhomogeneous random graph model which features three fundamental properties that are often present in real-world networks: (1) Scale-free: the degree of the nodes follows a power law; (2) Small-world: two far-away nodes have typically a small graph distance; (3) Positive clustering coefficient: two nodes with a common neighbour have a good chance to be linked. We study the mixing time of the simple random walk on this structure in one dimension and depict a rich phase diagram in the parameters of the model. In particular, we prove that the presence of hubs can speed up the mixing of the chain. Joint work with Alessandra Cipriani (UCL)

Add to calendar :

Date/Time : 16 Aug 2022 16:00
Venue : via Zoom
Speaker : Piyush Srivastava, Tata Institute of Fundamental Research

Join Zoom Meeting
https://nus-sg.zoom.us/j/83199111482?pwd=L09Yd054dDNTbDBpRkNtc0tmQnk5Zz09

Meeting ID: 831 9911 1482
Passcode: 569991

Abstract:  This series of lectures will survey various applications to algorithms of a collection of techniques that are broadly referred to as “geometry of polynomials”. Specific examples include:

1) Real stable polynomials and constructions of Ramanujan expanders
2) Lee-Yang theory and deterministic “approximate counting” algorithms”
3) Lorentzian or “strongly log concave” polynomials and applications to sampling

Add to calendar :

Date/Time : 26 Jul 2022 16:00
Venue : via Zoom
Speaker : Piyush Srivastava, Tata Institute of Fundamental Research

Join Zoom Meeting
https://nus-sg.zoom.us/j/83199111482?pwd=L09Yd054dDNTbDBpRkNtc0tmQnk5Zz09

Meeting ID: 831 9911 1482
Passcode: 569991

This series of lectures will survey various applications to algorithms of a collection of techniques that are broadly referred to as “geometry of polynomials”. Specific examples include:

1) Real stable polynomials and constructions of Ramanujan expanders
2) Lee-Yang theory and deterministic “approximate counting” algorithms”
3) Lorentzian or “strongly log concave” polynomials and applications to sampling.

Add to calendar :

Date/Time : 19 Jul 2022 16:00
Venue : via Zoom
Speaker : Piyush Srivastava, Tata Institute of Fundamental Research

Join Zoom Meeting
https://nus-sg.zoom.us/j/83199111482?pwd=L09Yd054dDNTbDBpRkNtc0tmQnk5Zz09

Meeting ID: 831 9911 1482
Passcode: 569991

This series of lectures will survey various applications to algorithms of a collection of techniques that are broadly referred to as “geometry of polynomials”. Specific examples include:

1) Real stable polynomials and constructions of Ramanujan expanders
2) Lee-Yang theory and deterministic “approximate counting” algorithms”
3) Lorentzian or “strongly log concave” polynomials and applications to sampling.

Add to calendar :

Date/Time : 12 Jul 2022 16:00
Venue : via Zoom
Speaker : Piyush Srivastava, Tata Institute of Fundamental Research

Join Zoom Meeting
https://nus-sg.zoom.us/j/83199111482?pwd=L09Yd054dDNTbDBpRkNtc0tmQnk5Zz09

Meeting ID: 831 9911 1482
Passcode: 569991

This series of lectures will survey various applications to algorithms of a collection of techniques that are broadly referred to as “geometry of polynomials”. Specific examples include:

1) Real stable polynomials and constructions of Ramanujan expanders
2) Lee-Yang theory and deterministic “approximate counting” algorithms”
3) Lorentzian or “strongly log concave” polynomials and applications to sampling.

Add to calendar :

Date/Time : 12 May 2022 16:00
Venue : via Zoom
Speaker : Vlad-Dumitru Margarint, NYU Shanghai

Join Zoom Meeting
https://nus-sg.zoom.us/j/81881463944?pwd=M2Y0OVpiSUsxRGdnWG9DWm9CY0o1UT09

Meeting ID: 818 8146 3944
Passcode: 177270

Abstract: In this talk I will introduce Schramm-Loewner Evolutions (SLE) theory and I will discuss some PDEs that appear naturally in this study. I will spend most of the time on a specific PDE that models a fundamental quantity in SLE theory: the density of the law of the SLE tip. I will present a series of recent results on this object based on the analysis of this PDE, obtained jointly with Yizheng Yuan and Oleg Butkovksy, as well as some open problems. I will also describe the progress of the SLE community in the study of a different PDE and describe some open problems as an invitation to the community for further discussions!

Add to calendar :

Date/Time : 30 Mar 2022 09:00
Venue : via Zoom
Speaker : Wei Kuo Chen, University of Minnesota

Join Zoom Meeting
https://nus-sg.zoom.us/j/81402485618?pwd=WlBSN2NhM2xXaGlTc1NhTFBqRjRIUT09

Meeting ID: 814 0248 5618
Passcode: 266695

Abstract: The Grothendieck L_p problem is defined as an optimization problem that maximizes the quadratic form of a Gaussian matrix over the unit L_p ball. The p=2 case corresponds to the top eigenvalue of the Gaussian Orthogonal Ensemble, while p=\infty this problem is known as the ground state energy of the Sherrington-Kirkpatrick mean-field spin glass model and its limit can be expressed by the famous Parisi formula. In this talk, I will describe the limit of this optimization problem for general p and discuss some results on the behavior of the near optimizers along with some open problems. This is based on a joint work with Arnab Sen.

Add to calendar :

Date/Time : 02 Mar 2022 16:30
Venue : via Zoom
Speaker : Subhajit Goswami, Tata Institute of Fundamental Research

Join Zoom Meeting
https://nus-sg.zoom.us/j/86418786459?pwd=cVE2Wk5OSWthOUJtSEF5L0RzNURIdz09

Meeting ID: 864 1878 6459
Passcode: 815262

Abstract: In this talk I will give a brief introduction to Liouville first-passage percolation (LFPP) which is a model for random metric on the plane or a finite planar grid graph. It is studied primarily as a way to understand the random metric associated with Liouville quantum gravity (LQG). In short, the Liouville quantum gravity is a one parameter family of “canonical” random metrics on the plane. I will discuss a result on the estimates of the typical distance between two points and its implication for the Hausdorff dimension of the LQG distance. I will highlight how this estimate refutes a conjecture made in the physics literature about the LQG distance.

Add to calendar :