Shadows of Kerr Black Holes with Scalar Hair

Using backwards ray tracing, we study the shadows of Kerr black holes with scalar hair (KBHSH). KBHSH interpolate continuously between Kerr BHs and boson stars (BSs), so we start by investigating the lensing of light due to BSs. Moving from the weak to the strong gravity region, BSs-which by themselves have no shadows-are classified, according to the lensing produced, as (i) noncompact, which yield not multiple images, (ii) compact, which produce an increasing number of Einstein rings and multiple images of the whole celestial sphere, and (iii) ultracompact, which possess light rings, yielding an infinite number of images with (we conjecture) a self-similar structure. The shadows of KBHSH, for Kerr-like…

• UD
  Universidade de Coimbra
• CF
  Center for Research and Development in Mathematics and Applications

  Award: UID/MAT/04106/2013
• FP
  Fundação para a Ciência e a Tecnologia

  Awards: PTDC/FIS/116625/2010, PD/BD/109532/2015, UID/MAT/04106/2013, 04106, FP7-PEOPLE-2011, NRHEP295189
• FP
  FP7 People: Marie-Curie Actions

  Award: FP7-PEOPLE-2011-IRSES