Colloquia & Seminars

Speaker: Jesse Thaler

Title: What Observables are Safe to Calculate?

Quantum Matter in Mathematics and Physics Seminar Speaker: Jesse Thaler, MIT Title: What Observables are Safe to Calculate? Abstract: In collider physics, perturbative quantum field theory is the workhorse framework for computing theoretical predictions to compare to experimental measurements. An observable is called "safe" if its cross section can be predicted order-by-order in perturbation theory with controlled non-perturbative corrections. In this talk, I show that naive definitions of "safety" are inadequate to determine which observable are perturbatively calculable. I then argue for a more refined definition of safety based on principles from optimal transport theory.

Speaker: Matteo Parisi

Title: Member Seminar

CMSA Member Seminar Speaker: Matteo Parisi, Harvard CMSA

Speaker: Lance Dixon

Title: The DNA of Particle Scattering

Colloquium Speaker: Lance Dixon (SLAC, Stanford University) Title: The DNA of Particle Scattering Abstract: At the Large Hadron Collider, the copious scattering of quarks and gluons in quantum chromodynamics (QCD) produces Higgs bosons and many backgrounds to searches for new physics.  At short distances, scattering in QCD can be evaluated in perturbation theory and leads to highly intricate, multivariate mathematical functions such as generalized polylogarithms.  To gain further insight, one can study a cousin of QCD called planar N=4 super-Yang-Mills theory.  Some processes in this theory can be computed to eighth order in perturbation theory, versus second or third order in QCD.  The computation and analysis of these results rely on a Hopf algebra coaction on polylogarithms.  Its maximal iteration...

Title: CMSA Q&A Seminar 4/30/2024

Speaker: Lakshminarayanan Mahadevan Question: What is morphogenesis? (Morphogenesis: geometry and biology)

Title: Non-dispersive one-way signal amplification in sonic metamaterials

Active Matter Seminar Speaker: Jayson Paulose, University of Oregon Title: Non-dispersive one-way signal amplification in sonic metamaterials Abstract: Parametric amplification -- injecting energy into waves via periodic modulation of system parameters -- is typically restricted to specific multiples of the modulation frequency. However, broadband parametric amplification can be achieved in active metamaterials which allow local parameters to be modulated both in space and in time. Inspired by the concept of luminal metamaterials in optics, we describe a mechanism for one-way amplification of sound waves across an entire frequency band using spacetime-periodic modulation of local stiffnesses in the form of a traveling wave. When the speed of the modulation wave approaches that of the speed of sound in the metamaterial...

Speaker: Sarah Harrison

Title: Colloquium

Colloquium Speaker: Sarah Harrison, Northeastern University

Speaker: Albert Law

Title: General Relativity Seminar

General Relativity Seminar Speaker: Albert Law, Stanford

Title: Member Seminar

CMSA Member Seminar Speaker: Sergiy Verstyuk

Speaker: Eric Pichon-Pharabod

Title: Algebraic Geometry in String Theory Seminar

Algebraic Geometry in String Theory Seminar Speaker: Eric Pichon-Pharabod, Universite Paris-Saclay

Title: Quantum Matter in Mathematics and Physics Seminar

Quantum Matter in Mathematics and Physics Seminar

Speaker: Robert Moscrop

Title: Member Seminar

CMSA Member Seminar Speaker: Robert Moscrop, Harvard CMSA

Speaker: Mikhail Molodyk

Title: General Relativity Seminar

General Relativity Seminar Speaker: Mikhail Molodyk, Stanford

Title: General Relativity Seminar

General Relativity Seminar Speaker: Marcelo Disconzi, Vanderbilt University

Title: Member Seminar

CMSA Member Seminar Speaker: Jue Liu

Speaker: Franco Rota

Title: Algebraic Geometry in String Theory Seminar

Algebraic Geometry in String Theory Seminar Speaker: Franco Rota, University of Glasgow