Wed, 22 Oct 2025
11:00
11:00
L4
Two partition-function approaches to non-symmetric random tensor eigenvalues
Giacomo La Scala
(Oxford University)
Thu, 23 Oct 2025
14:00
14:00
L4
Multifold Schwinger-Keldysh EFT -- what I understand and what I don't
Akash Jain
Abstract
The organisers asked me to give a brief talk on what I’ve been thinking about lately. So, I’ll tell you about Schwinger-Keldysh EFTs: an EFT framework for non-equilibrium dissipative systems such as hydrodynamics. These are built on a closed-time contour that runs forward and backward in time, allowing access to a variety of non-equilibrium observables. However, these EFTs fundamentally miss a wider class of observables, called out-of-time-ordered correlators (OTOCs), which are closely tied to quantum chaos. In this talk, I’ll share some thoughts on extending Schwinger-Keldysh EFTs to multifold contours that capture such observables. I’ll also touch on the discrete KMS symmetry of thermal systems, which generalises from Z_2 in the single-fold case to the dihedral group in the -fold case. With any luck, I’ll reach the point where I’m stuck and you can help me figure it out.
Tue, 14 Oct 2025
14:00 -
15:00
L4
An exponential upper bound on induced Ramsey numbers
Marcelo Campos
(Instituto Nacional de Matemática Pura e Aplicada (IMPA))
Abstract
The induced Ramsey number $R_{ind}(H)$ of a graph $H$ is the minimum number $N$ such that there exists a graph with $N$ vertices for which all red/blue colorings of its edges contain a monochromatic induced copy of $H$. In this talk I'll show there exists an absolute constant $C > 0$ such that, for every graph $H$ on $k$ vertices, these numbers satisfy $R_{ind}(H) ≤ 2^{Ck}$. This resolves a conjecture of Erdős from 1975.
This is joint work with Lucas Aragão, Gabriel Dahia, Rafael Filipe and João Marciano.