Shaving off Black Hole Soft Hair

TL;DR

This paper argues that properly dressed hard states in quantum field theory render the soft quanta contributions trivial, potentially resolving the black hole information paradox by reformulating it in terms of dressed states.

Contribution

It demonstrates that dressing in and out states in the S-matrix framework trivializes soft quanta effects, offering a new perspective on black hole hair and information retention.

Findings

Soft-quanta-dependent parts of the S-matrix become trivial with proper dressing.

The information paradox can be reformulated using dressed hard states.

Soft hair may not carry independent information when states are properly dressed.

Abstract

A recent, intriguing paper by Hawking, Perry and Strominger suggests that soft photons and gravitons can be regarded as black hole hair and may be relevant to the black hole information paradox. In this note we make use of factorization theorems for infrared divergences of the S-matrix to argue that by appropriately dressing in and out hard states, the soft-quanta-dependent part of the S-matrix becomes essentially trivial. The information paradox can be fully formulated in terms of dressed hard states, which do not depend on soft quanta.