Extended BMS representations and strings

TL;DR

This paper constructs detailed irreducible representations of the extended BMS group with super rotations in 3D and 4D, comparing them to Poincare and global BMS representations, and suggests they are carried by strings.

Contribution

It provides a comprehensive construction of extended BMS group representations with super rotations, highlighting their string-like nature.

Findings

Extended BMS representations match the rest frame momenta of Poincare particles.

Comparison shows differences between BMS and Poincare group representations.

Super rotations are essential in characterizing these extended BMS representations.

Abstract

We construct in detail the irreducible representations of the BMS group with super rotations in three and four dimensions that have the same rest frame momenta as the massive and massless Poincare point particles. We compare these representations to those of the Poincare group and also to the analogous representations of global BMS. We argue that these extended BMS representations are carried by a string rather than a point particle. The super rotations play a crucial role in our discussions.