Scalar-Wave Signatures of Wormholes in Dark Matter Halos

Abstract

We identify scalar-wave signatures of massless fields propagating in static, spherically symmetric wormholes embedded within realistic dark matter halos. Starting from a general line element with arbitrary redshift and shape functions, we recast the radial Klein-Gordon equation in Schr\"odinger form, explicitly separating contributions from gravitational redshift, spatial curvature, and angular momentum. The dynamics reduce to a generalized Helmholtz equation with a space- and frequency-dependent effective refractive index that encodes the throat geometry, halo curvature, and centrifugal effects, asymptotically recovering free-space propagation. Applying this framework to Navarro-Frenk-White, Thomas-Fermi Bose-Einstein condensate, and Pseudo-Isothermal halo models, and considering zero, Teo-type, and cored redshift functions, we uncover evanescent regions and suppression of high-angular-momentum modes in the vicinity of the throat. High-frequency waves approach the geometric-optics regime, whereas low-frequency modes exhibit strong curvature-induced localization. In the geometric-optics limit, the effective refractive index reproduces null-geodesic trajectories, while finite-frequency effects capture evanescent zones and tunneling phenomena. This work establishes the first exact, non-perturbative framework linking wormhole geometry and realistic dark matter halos to observable scalar-wave propagation phenomena, including evanescence, mode suppression, and frequency-dependent localization.