Universality of free fall versus ephemeris

TL;DR

This paper explores how a light scalar field interacting with matter can violate the weak equivalence principle and proposes using INPOP ephemeris data to test these potential violations, revealing new aspects of universality of free fall.

Contribution

It introduces a novel scenario where the universality of free fall can manifest differently and outlines a method to constrain this using planetary ephemeris data.

Findings

Potential violations of free fall are detectable with ephemeris data.

The new scenario offers a different perspective on equivalence principle tests.

Constraints on scalar field interactions can be improved with ephemeris analysis.

Abstract

When a light scalar field with gravitational strength interacts with matter, the weak equivalence principle is in general violated, leading for instance to a violation of the universality of free fall. This has been known and tested for a while. However, recent developments [Minazzoli & Hees, PRD 2016] showed that a novel manifestation of the universality of free fall can appear in some models. Here we discuss this new scenario and expose how we intend to constrain it with INPOP ephemeris.