Wormholes without exotic matter: quasinormal modes, echoes and shadows
M.S. Churilova, R.A. Konoplya, Z. Stuchlík, A. Zhidenko
Abstract
Abstract An analytical solution representing traversable asymptotically flat and symmetric wormholes was obtained without adding exotic matter in two different theories independently: in the Einstein-Maxwell-Dirac theory and in the second Randall-Sundrum brane-world model. Further, a smooth normalizable asymmetric wormhole solution has been recently obtained numerically in the Einstein-Maxwell-Dirac theory. Using the time-domain integration method we study quasinormal ringing of all these wormholes with emphasis to the regime of mimicking the near extremal Reissner-Nordström black holes, which is characterised by echoes. In addition, we calculate radius of shadows cast by these wormholes.