Direct Detection of Ultralight Dark Matter via Astronomical Ephemeris

TL;DR

This paper proposes a new method to detect ultralight dark matter by analyzing its subtle effects on solar system bodies' motions, leveraging precise astronomical ephemeris data.

Contribution

It introduces a novel detection approach based on the interaction between ultralight dark matter and nucleons, utilizing astronomical ephemeris to set strong constraints.

Findings

Astronomical ephemeris can detect ultralight dark matter interactions.

The resistant force from dark matter affects solar system bodies' motions.

Strong constraints on dark matter-nucleon interactions are established.

Abstract

A novel idea of the direct detection to search for a ultralight dark matter based on the interaction between the dark matter and a nucleon is proposed. Solar system bodies feel the dark matter wind and it acts as a resistant force opposing their motions. The astronomical ephemeris of solar system bodies is so precise that it has a strong capability to detect a dark matter whose mass is much lighter than O(1) eV. We have estimated the resistant force based on the calculation of the elastic scattering cross section between the dark matter and the bodies beyond the Born approximation, and show that the astronomical ephemeris indeed put a very strong constraint on the interaction between the dark matter and a nucleon, depending on how smoothly the ultralight dark matter is distributed at the scale smaller than the celestial bodies in our solar system.