## South East Mathematical Physics Seminars

These seminars are organised by Clare Dunning, University of Kent.

These seminars take place bi-weekly on a Tuesday at 14:00-15:00 (BST)

To sign up to participate in these seminars, please complete this registration form

The South East Mathematical Physics seminars bring together mathematical physicists based in and around the South East of England working on any aspect of mathematical physics, supported by a London Mathematical Society Joint Research Groups grant and hosted in virtual format by ICMS.

You will be sent a link to the Zoom meeting first thing on Tuesday mornings.

All recordings of seminars can be found here

### Forthcoming Seminars

**Tuesday 22 September**

Tommaso MacrelliTitle:

BV formalism, QFT and Gravity: a Homotopy perspectiveAbstract: After a review of Batalin-Vilkovisky formalism and homotopy algebras, we discuss how these structures emerge in quantum field theory and gravity. We focus then on the application of these sophisticated mathematical tools to scattering amplitudes (both tree- and loop-level) and to the understanding of the dualities between gauge theories and gravity, highlighting generalizations of old results and presenting new ones.

### Previous Seminar

**Tuesday 08 September**

Edoardo Vescovi, Imperial CollegeTitle:

Probing Wilson loops at finite coupling via integrabilityAbstract: The concept of “boundary” that preserves the integrability of a 2d theory has led to a plethora of exact results for observables in a variety of (also higher-dimensional) integrable QFTs. In this seminar, we present the results of a programme based on this idea for the correlator of a supersymmetric Wilson loop and a local operator in N=4 super Yang-Mills theory.

First, we reformulate the path-integral computing this observable in free theory as the overlap between a matrix product state (associated to the Wilson loop) and an energy eigenstate of a spin-chain (associated to the local operator). This allows to draw a comparison with other observables computed by similar approach and to support the identification of the 1/2-BPS circular Wilson loop with an integrable boundary state. Second, we explain how to formulate the “integrable bootstrap” for the correlator involving the circular loop at finite coupling.

**Tuesday 25 August**

Julius Julius, King's CollegeTitle:

Excited States of One Dimensional Defect CFTs: A Quantum Spectral Curve ApproachAbstract: I will describe the Quantum Spectral Curve (QSC), a powerful integrability based approach that was originally developed to study the spectrum of planar $\mathcal{N} = 4$ supersymmetric Yang-Mills theory, and how it is modified to study the anomalous dimension of a cusped Maldacena-Wilson line with scalar insertions at the cusp. In the straight line limit we interpret the excited states of the QSC as insertions of scalar operators coupled to the line. Since Maldacena-Wilson lines with such geometries are one dimensional superconformal defects in the four dimensional theory, the same setup can be used to study the spectrum of one dimensional CFTs non-perturbatively. For the case of one scalar insertion, we compute a five- loop perturbative result analytically at weak coupling and the first four orders in the $1/\sqrt{\lambda}$ expansion at strong coupling, confirming all previous analytic results. In addition, we find the non-perturbative spectrum numerically and show that it interpolates smoothly between the weak and strong coupling predictions. I will also present some new results and some speculations for the case of an insertion of two scalars.

**Tuesday 11 August**

Zhenghao Zhong, Imperial College London

Title:

Magnetic quivers from brane webs with O5 planesAbstract: The Higgs branch of 5d N=1 SQCD theories at infinite gauge coupling is often inaccessible via standard tools. The recently introduced concept of magnetic quivers proves to be a powerful tool able to probe the finite and infinite coupling limits in a uniform manner. In this talk, I will focus on 5d N=1 SQCD theories whose Higgs branch at infinite coupling exhibits exceptional global symmetries. By realizing the theory as a brane web configuration with orientifold planes, the corresponding unitary-orthosymplectic magnetic quivers can then be readily obtained.Title to follow

Zoom is the online platform being used to deliver this seminar series.