S-wave scattering of electrons off of heavy magnetic monopoles is an important problem both in formal theory and in particle phenomenology. It has long been understood that this scattering can be effectively studied in two-dimensional conformal field theory with a recently appreciated crucial role played by topological line defects and generalized global symmetry. We use the formalism of...
In this talk, I will examine the dynamics of the fermion–rotor system, originally introduced by Polchinski as a toy model for monopole–fermion scattering. Despite its simplicity, the system is surprisingly subtle, with ingoing and outgoing fermion fields carrying different quantum numbers. I will show that the rotor acts as a twist operator in the low-energy theory, changing the quantum...
I will explore the Kramers-Wannier duality in the continuum and comment on its implications for the electroweak hierarchy problem.
In this talk, we will answer the question: What does a QCD Wilson line flow to in the IR chiral Lagrangian? We will first present a symmetry-based argument showing that the Wilson line is not completely screened in the IR. We then propose a disorder operator realization of the Wilson line in the chiral Lagrangian. This allows us to model heavy-light mesons and baryons and describe the...
Conformal boundary conditions appear in various different contexts, in the study of impurities, scattering of massless particles off a heavy monopole, D-branes, and so on. I will discuss a new “higher” geometric structure the space of conformal boundary conditions possesses in 1+1d conformal field theories.