Gravitational lensing by phantom black holes

Abstract

In some models dark energy is described by phantom scalar fields (scalar fields with the ``wrong'' sign of the kinetic term in the Lagrangian). In the current paper we study the effect of phantom scalar field and/or phantom electromagnetic field on gravitational lensing by black holes in the strong deflection regime. The black-hole solutions that we have studied have been obtained in the frame of the Einstein-(anti-)Maxwell-(anti)dilaton theory. The numerical analysis shows a considerable effect of the phantom scalar and electromagnetic fields on the angular position, brightness, and separation of the relativistic images.