Photonic Modes in Bonnor-Melvin Domain Walls: Photon Rings

Abstract: We investigate the relativistic dynamics of vector bosons in a ((2+1))-dimensional Bonnor-Melvin magnetic spacetime, which features a magnetic field aligned with the symmetry axis (z) and a nonzero cosmological constant (\Lambda). This cylindrically symmetric background preserves Lorentz invariance under boosts in the (z)-direction and corresponds to the ((2+1+0))-brane solution of the Bonnor-Melvin magnetic spacetime in gravity coupled to nonlinear electrodynamics. By deriving the radial wave equation, which is mathematically identical to the Helmholtz equation, we obtain exact eigenvalue solutions applicable to both massive and massless vector bosons (photons). Notably, we find that photons acquire a nonzero ground-state energy. Furthermore, we demonstrate that their states form magnetized, rotating ring-like structures, which can be interpreted as rotating magnetic vortices.