Phenomenological Motivation for Gravitational Positivity Bounds: A Case Study of Dark Sector Physics

TL;DR

This paper explores how gravitational positivity bounds constrain dark sector physics, particularly dark photon models, highlighting their relevance to ongoing experiments and the importance of understanding negativity allowances in scattering amplitudes.

Contribution

It provides a detailed analysis of gravitational positivity bounds in dark photon scenarios, emphasizing their significance for experimental physics and the swampland program.

Findings

Positivity bounds are approximately valid even with gravity.

Negativity allowances in scattering amplitudes are crucial for dark sector models.

Dark photon scenarios illustrate the impact of gravitational positivity bounds.

Abstract

Positivity bounds on scattering amplitudes provide a necessary condition for a low-energy effective field theory to have a consistent ultraviolet completion. Their extension to gravity theories has been studied in the past years aiming at application to the swampland program, showing that positivity bounds hold at least approximately even in the presence of gravity. An issue in this context is how much negativity is allowed for a given scattering process. In this paper we address importance of this rather technical issue by demonstrating that it is relevant to physics within the scope of ongoing experiments, especially in the context of dark sector physics. In particular, we provide detailed analysis of dark photon scenarios as an illustrative example. This motivates further studies on gravitational positivity bounds.