  We study the linear polarization from the accretion disk around a class of
static traversable wormholes. Applying the simplified model of a magnetized
fluid ring orbiting in the equatorial plane, we search for characteristic
signatures, which could distinguish wormhole from black hole spacetimes by
their polarization properties. For the purpose we analyse the direct polarized
images for different inclination angles, the strongly lensed indirect images,
and the polarized radiation which reaches the asymptotic observer through the
wormhole throat, and compare to the Schwarzschild black hole. For small
inclination angles the two types of compact objects lead to a very similar
polarization pattern of the direct images. More significant distinctions are
observed for the strongly lensed indirect images, where the polarization
intensity in the wormhole spacetimes can grow up to an order of magnitude
compared to the Schwarzschild black hole. Detecting radiation from the region
across the wormhole throat leads to the formation of an additional structure of
ring images with distinct polarization properties. The twist of the
polarization vector around the ring is less pronounced, thus modifying the
polarization pattern, and the polarization intensity can increase with an order
of magnitude compared to the radiation from our universe. Thus, while it could
be difficult to distinguish wormhole spacetimes by their direct polarized
images, the strongly lensed images and the polarization of the radiation
through the wormhole throat provide characteristic signatures which can serve
as probes for horizonless objects.

General Relativity and Quantum Cosmology