Classical Limit of Higher-Spin String Amplitudes

Abstract

It has been shown that a special set of three-point amplitudes between two massive spinning states and a graviton reproduces the linearised stress-energy tensor for a Kerr black hole in the classical limit. In this work we revisit this result and compare it to the analysis of the amplitudes describing the interaction of leading Regge states of the open and closed superstring. We find an all-spin result for the classical limit of two massive spinning states interacting with a photon or graviton. This result differs from Kerr and instead matches the current four-vector and the stress-energy tensor generated by a classical string coupled to electromagnetism and gravity respectively. For the superstring amplitudes, contrary to the black-hole case, we find that the spin to infinity limit is necessary to reproduce the classical spin multipoles.

Classical off-shell currents

“…[29]. The n = 2 current with spinning massive particles is relevant in the context of ongoing discussions of higher spin gravitational Compton amplitudes in the classical limit [30][31][32][33][34][35][36][37][38][39][40][41].…”

Transient chaos analysis of string scattering

“…The calculation of the HES amplitudes was developed in[19]. See also[20,21] for HES states studied from the viewpoint of cosmic strings, and a recent paper[22] for a classical limit of HES amplitudes.…”