Causality in the presence of stacked shockwaves
File(s)
Published version
Author(s)
Chen, Calvin Y-R
Margalit, Aoibheann
de Rham, Claudia
Tolley, Andrew J
Type
Journal Article
Abstract
Relativistic causality constrains the 𝑆-matrix both through its analyticity, and by imposing lower bounds on the scattering time delay. These bounds are easiest to determine for spacetimes which admit either a timelike or null Killing vector. We revisit a class of pp-wave spacetimes and carefully determine the scattering time delay for arbitrary incoming states in the eikonal, semiclassical, and Born approximations. We apply this to the effective field theory of gravity in arbitrary dimensions. It is well-known that higher-dimension operators such as the Gauss-Bonnet term, when treated perturbatively at low energies, can appear to make both positive and negative contributions to the time delays of the background geometry. We show that even when multiple shockwaves are stacked, the corrections to the scattering time delay relative to the background are generically unresolvable within the regime of validity of the effective field theory so long as the Wilson coefficients are of order unity. Phrased the other way, this can be read as a bound on the Wilson coefficient from infrared causality which are consistent with positivity/bootstrap bounds.
Date Issued
2025-01-15
Date Acceptance
2024-12-16
Citation
Physical Review D: Particles, Fields, Gravitation and Cosmology, 2025, 111 (2)
ISSN
1550-7998
Publisher
American Physical Society
Journal / Book Title
Physical Review D: Particles, Fields, Gravitation and Cosmology
Volume
111
Issue
2
Copyright Statement
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3 .
License URL
Identifier
10.1103/PhysRevD.111.024066
Subjects
AMPLITUDES
Astronomy & Astrophysics
CONJUGATE
CONSISTENCY
MATRIX
Physical Sciences
Physics
Physics, Particles & Fields
QUANTUM-GRAVITY
QUARTIC EFFECTIVE ACTION
Science & Technology
SPACETIME
TERMS
TIME OPERATOR
WAVE
Publication Status
Published
Article Number
024066
Date Publish Online
2024-01-30