Gravitational Focusing of Low-Velocity Dark Matter on the Earth's Surface

TL;DR

This paper demonstrates that Earth's gravity significantly enhances the local density of low-velocity dark matter, creating a focal point on the surface and causing diurnal modulation of dark matter detection signals.

Contribution

It introduces the concept that Earth acts as a gravitational lens for low-velocity dark matter, revealing a new mechanism affecting local dark matter density and detection prospects.

Findings

Earth's gravity focuses low-velocity dark matter on its surface.

The focal point occurs at a DM flow speed of about 17 km/s.

Diurnal modulation of local DM density is influenced by Earth's gravity.

Abstract

We show that the Earth acts as a high-efficiency gravitational collector of low-velocity flow of dark matter (DM). The focal point appears on the Earth's surface, when the DM flow speed is about 17 km/s with respect to the geo-center. We discuss diurnal modulation of the local DM density influenced by the Earth's gravity. We also touch upon similar effects on galactic and solar system objects.