Dark Spin-2 Field Solitons as a Source of Electromagnetic Radiation

Spin-$s$ light dark boson particles can exhibit wave-like behavior, capable of forming long-lived, coherent, spatially localized structures known as solitons. This work considers the possibility that a light spin-2 particle might be part of or all the dark matter content of the Universe, which could result in a significant fraction of solitons existing today in galactic halos. If these dark matter particles interact with electromagnetism through dimension-6 operators, the solitons may experience parametric resonance of photons triggered by the surrounding electromagnetic field. We explore the feasibility and key characteristics of this electromagnetic radiation, as well as the potential for detection through soliton mergers using ground-based facilities.