Late Time Magnetogenesis from Ultralight Scalar Dark Matter
Abstract
Assuming that Dark Matter is an ultralight scalar field which is coupled to electromagnetism via a gauge-kinetic function and which at the time of recombination is oscillating coherently over a Hubble patch, we show that there is a tachyonic instability for the gauge field modes which leads to the generation of magnetic fields on cosmological scales of sufficient amplitude to explain observations.
Fields of Study & Subjects
Dark Matter and Cosmic Phenomena
Cosmology and Gravitation Theories
Pulsars and Gravitational Waves Research
Publication details
- Journal / source
- arXiv (Cornell University)
- Publication date
- 1 January 2026
- Document type
- Preprint