Fifth-Force Screening around Extremely Compact Sources

TL;DR

This paper investigates how fifth forces are suppressed around extremely compact objects in scalar field theories with screening mechanisms, extending understanding from extended objects to point-like sources.

Contribution

It provides a detailed analysis of fifth-force screening in the limit of highly compact sources, a regime less understood compared to extended objects.

Findings

Screening behavior differs for point-like sources compared to extended objects.

The study clarifies conditions under which fifth forces are suppressed around compact sources.

Results inform experimental tests involving small or dense objects.

Abstract

Many non-linear scalar field theories possess a screening mechanism that can suppress any associated fifth force in dense environments. As a result, these theories can evade local experimental tests of new forces. Chameleon-like screening, which occurs because of non-linearities in the scalar potential or the coupling to matter, is well understood around extended objects. However, many experimental tests of these theories involve objects with spatial extent much smaller than the scalar field's Compton wavelength, and which could therefore be considered point-like. In this work, we determine how the fifth forces are screened in the limit that the source objects become extremely compact.