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Ellen D.B. Riggle receives Graduate School's Kirwan Memorial Prize

By Harper Propst 

LEXINGTON, Ky. (June 12, 2025) — Each year, the University of Kentucky Graduate School recognizes exceptional faculty for their achievements in graduate education and scholarly research. Ellen D.B. Riggle, Ph.D, receives the Albert D. and Elizabeth H. Kirwan Memorial Prize, awarded for outstanding contributions to original research and scholarship.

Physics & Astronomy String Theory Seminar

NB: non-standard time!


Title: Symmetry-weighted ensemble averaging from TQFT gravity

Abstract: In a recently proposed framework of TQFT gravity (2310.13044, 2405.20366) -- a toy model of AdS3 gravity -- a bulk 3d TQFT summed over all topologies is shown to be dual to a unitary ensemble of boundary 2d CFTs. I will show that the CFTs in this ensemble are weighted by the inverse of the order of their symmetry group (relative to the categorical symmetry provided by the bulk TQFT as a SymTFT). Mathematically, this is the natural measure over the groupoid of the TQFT Lagrangian algebras that construct the CFTs, and the holographic duality then provides a generalization of the Siegel-Weil formula beyond averaging over bosonic lattice-CFTs. I will also discuss some examples for rational CFTs as well as implications to noncompact TQFTs and pure gravity.

Date:
-
Location:
CP 303
Event Series:

Physics & Astronomy Nuclear Science Seminar

Title: From chiral effective field theory to perturbative QCD: A Bayesian model mixing approach to neutron star matter

Abstract: Constraining the equation of state (EOS) of strongly interacting, dense matter is the focus of significant experimental, observational, and theoretical effort. While chiral effective field theory (EFT) can describe the EOS between the typical densities of nuclei and those in the outer cores of neutron stars, perturbative QCD (pQCD) can be applied to properties of deconfined quark matter, both with quantified theoretical uncertainties.

However, describing the full range of densities in between with a single EOS that has well-quantified uncertainties is a challenging problem. Bayesian model mixing (BMM) can help bridge the gap between the two theories.

In this talk, I will present a BMM framework that can combine EOS constraints from different density regions in a principled way to construct a globally predictive, composite EOS model based on Gaussian processes (GPs). I will discuss applications of this BMM framework to the EOS and structure of neutron stars, as well as the statistical uncertainty quantification of the underlying microscopic EOS calculations.

Date:
-
Location:
CP 179
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