Triangle Seminars
Monday, 20 Oct 2025
Lonti: Introduction to Matrix Models (1/4)
📍 London
Fedor Levkovich-Maslyuk
(City U.)
Abstract:
Models of random matrices can be viewed as zero-dimensional analogs of usual field theory. Despite decades of exploration, matrix models remain at the forefront of intensive research, motivated by a rich web of connections to string theory, quantum gravity, integrability, Yang-Mills theory, combinatorics, geometry and representation theory. These lectures will present a pedagogical introduction to the subject.
Lecture 1. Motivation and basic definitions. Hermitian matrix models: Feynman rules, ribbon graphs, large N genus expansion.
Models of random matrices can be viewed as zero-dimensional analogs of usual field theory. Despite decades of exploration, matrix models remain at the forefront of intensive research, motivated by a rich web of connections to string theory, quantum gravity, integrability, Yang-Mills theory, combinatorics, geometry and representation theory. These lectures will present a pedagogical introduction to the subject.
Lecture 1. Motivation and basic definitions. Hermitian matrix models: Feynman rules, ribbon graphs, large N genus expansion.
Posted by: Damian Galante
Tuesday, 21 Oct 2025
TBA
📍 London
Joydeep Chakravarty
(McGill University)
Gravity in the era of Stage IV Surveys
📍 London
Alessandra Silvestri
(Leiden University)
Abstract:
Stage IV Large Scale Structure Surveys are ushering in a new
era of precision cosmology! In this talk, I will explore the effort to test gravity on cosmological
scales, highlighting the theoretical advancements aimed at constructing
an optimal framework. I will also touch on the synergy with
gravitational wave surveys. Additionally, I will provide a detailed
review of recent findings based on currently available data and conclude
with an outlook on the challenges and future prospects in this field.
Stage IV Large Scale Structure Surveys are ushering in a new
era of precision cosmology! In this talk, I will explore the effort to test gravity on cosmological
scales, highlighting the theoretical advancements aimed at constructing
an optimal framework. I will also touch on the synergy with
gravitational wave surveys. Additionally, I will provide a detailed
review of recent findings based on currently available data and conclude
with an outlook on the challenges and future prospects in this field.
Posted by: Sebastian Cespedes
Wednesday, 22 Oct 2025
TBA
📍 London
Shinshei Ryu
(Princeton University)
Hyperbolic Mass in 2+1 Dimensions
📍 London
Raphaela Wutte
(University of Southampton)
Abstract:
Solutions to general relativity with a negative cosmological constant have received significant attention due to the conjectured AdS/CFT correspondence, a particularly well-understood example of which is exhibited in 2+1 dimensions. I will review known vacuum solutions to general relativity with a negative cosmological constant in 2+1 dimensions and discuss the difficulties in defining mass, which are resolved via minimisation using a positive energy theorem. I will present a gluing theorem for vacuum time-symmetric general-relativistic initial data sets in two spatial dimensions. By gluing two given time-symmetric vacuum initial data sets at conformal infinity, we obtain new time-symmetric vacuum initial data sets. I will sketch the derivation of the mass formulae of the resulting manifolds. Our gluing theorem yields complete manifolds with any mass aspect function, which are smooth except for one conical singularity.
Solutions to general relativity with a negative cosmological constant have received significant attention due to the conjectured AdS/CFT correspondence, a particularly well-understood example of which is exhibited in 2+1 dimensions. I will review known vacuum solutions to general relativity with a negative cosmological constant in 2+1 dimensions and discuss the difficulties in defining mass, which are resolved via minimisation using a positive energy theorem. I will present a gluing theorem for vacuum time-symmetric general-relativistic initial data sets in two spatial dimensions. By gluing two given time-symmetric vacuum initial data sets at conformal infinity, we obtain new time-symmetric vacuum initial data sets. I will sketch the derivation of the mass formulae of the resulting manifolds. Our gluing theorem yields complete manifolds with any mass aspect function, which are smooth except for one conical singularity.
Posted by: Andrew Svesko