Exploring an S-matrix for gravitational collapse II: a momentum space analysis

TL;DR

This paper analyzes a proposed S-matrix for transplanckian scattering using momentum space, complementing previous position-space work, and explores gravitational collapse phenomena with improved computational approaches.

Contribution

It introduces a momentum-space analysis of the S-matrix for gravitational scattering, enabling easier computation of graviton spectra and investigation beyond critical collapse points.

Findings

Momentum-space formulation simplifies graviton spectrum calculations.

Comparison validates the consistency of position and momentum-space approaches.

Preliminary insights into gravitational collapse regimes are obtained.

Abstract

We complement our earlier position-space exploration of a recently proposed S-matrix for transplanckian scattering by a momentum-space analysis. As in the previous paper, we restrict ourselves to the case of axisymmetric collisions of extended sources. Comparison between the two formulations allows for several cross-checks while showing their complementary advantages. In particular, the momentum-space formulation leads to an easier computation of the emitted-graviton spectra and to an attempt to study the system beyond its critical points into the presumed gravitational-collapse regime.