Galactic magnetic fields seeded by ultralight dark photons

2025/11/10 by Berger, Joshua, Bhoonah, Amit, Bramante, Joseph +3
#Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)

paper · doi:10.48550/arxiv.2511.07508

Abstract

In this work, we show that ultralight dark photons, which couple to the Standard Model photon through kinetic mixing, can potentially source galactic scale magnetic fields. Although these magnetic fields would be too weak to detect at present in galaxies due to plasma screening effects, we show that dark photons can provide the seed magnetic field strength (10^-20 G) required for dynamo amplification in galaxies. Such dynamo-amplified magnetic fields are consistent with observations of μG strength galactic magnetic fields.

Citations

• Signature of polarized ultralight vector dark matter in pulsar timing arrays
• Constraining exotic high-z reionization histories with Gaussian processes and the Cosmic Microwave Background
• Cosmological Magnetic Fields from Ultralight Dark Matter
• Sub-MHz Radio Background from Ultralight Dark Photon Dark Matter
• Hellings-Downs curve deformed by ultralight vector dark matter
• Wave Dark Matter
• Ultra-light dark matter
• 21cm absorption signal from charge sequestration
• In the beginning: the first sources of light and the reionization of the universe

Related

• Cosmological Magnetic Fields from Ultralight Dark Matter
• Thoughts on galactic magnetism
• The Galactic magnetic field and its lensing of ultrahigh energy and Galactic cosmic rays
• Dark photon limits from magnetic fields and astrophysical plasmas
• Photon mass new limits from strong photon-torsion coupling generation of primordial magnetic fields