On the Carrollian Nature of the Light Front

TL;DR

This paper explores the Carrollian structure of light-front quantum field theories, revealing that these theories inherently possess a magnetic Carroll Hamiltonian, and proposes a method to derive such Hamiltonians from Lorentzian theories.

Contribution

It introduces the concept of magnetic Carroll Hamiltonians in light-front theories and provides a method to derive them from Lorentzian field theories.

Findings

Light-front theories have a magnetic Carroll Hamiltonian.

Identification of subalgebras within the light-cone Poincaré algebra.

A method to derive magnetic Carroll Hamiltonians from Lorentzian theories.

Abstract

Motivated by recent advances in non-Lorentzian physics, we revisit the light-cone formulation of quantum field theories. We discuss some interesting subalgebras within the light-cone Poincar\'e algebra, with a key emphasis on the Carroll, Bargmann, and Galilean kinds. We show that theories on the light front possess a Hamiltonian of the magnetic Carroll type, thereby proposing a straightforward method for deriving magnetic Carroll Hamiltonian actions from Lorentzian field theories.