Astrophysical Signatures of Thin Accretion Disks in Wormhole Spacetimes

Abstract

We discuss the physical properties of matter forming thin accretion disks in static spherically symmetric and stationary axially symmetric wormhole spacetimes. More specifically, the time averaged energy flux, the disk temperature and the emission spectra of the accretion disks are obtained for these exotic geometries, and are compared with the Schwarzschild and Kerr solutions, respectively. For static and spherically symmetric wormholes it is shown that more energy is emitted from the disk than in the case of the Schwarzschild potential and the conversion efficiency of the accreted mass into radiation is more than a factor of two higher for wormholes than for static black holes. For axially symmetric wormhole spacetimes, by comparing the mass accretion with the one of a Kerr black hole, we verify that the intensity of the flux emerging from the disk surface is greater for wormholes than for rotating black holes with the same geometrical mass and accretion rate. We conclude that specific signatures appear in the electromagnetic spectrum, thus leading to the possibility of distinguishing wormhole geometries by using astrophysical observations of the emission spectra from accretion disks.