Quantum Tunneling of Ultralight Dark Matter Out of Satellite Galaxies

Understand

The idea of ultralight scalar (axion) dark matter is theoretically appealing and may resolve some small-scale problems of cold dark matter; so it deserves careful attention.

• In this work we carefully analyze tunneling of the scalar field in dwarf satellites due to the tidal gravitational force from the host halo.
• The tidal force is far from spherically symmetric; causing tunneling along the axis from the halo center to the dwarf, while confining in the orthogonal plane.
• We decompose the wave function into a spherical term plus higher harmonics, integrate out angles, and then numerically solve a residual radial Schr\"odinger-Poisson system.