Capture of dark matter by the Solar System

TL;DR

This paper investigates how the Solar System can gravitationally capture dark matter particles, providing analytical estimates for the capture cross-section and potential density enhancements, which are still below current observational limits.

Contribution

It derives analytical estimates for dark matter capture cross-section and bounds on the total captured mass, offering new insights into Solar System dark matter accumulation.

Findings

Capture can enhance dark matter density by up to three orders of magnitude.

Estimated captured dark matter mass remains below observational upper limits.

Analytical bounds help constrain dark matter density in the Solar System.

Abstract

We study the capture of galactic dark matter by the Solar System. The effect is due to the gravitational three-body interaction between the Sun, one of the planets, and a dark matter particle. The analytical estimate for the capture cross-section is derived and the upper and lower bounds for the total mass of the captured dark matter particles are found. The estimates for their density are less reliable. The most optimistic of them give an enhancement of dark matter density by about three orders of magnitudes compared to its value in our Galaxy. However, even this optimistic value remains below the best present observational upper limits by about two orders of magnitude.