4 papers
Light rings and optical appearances of naked singularities, solitons, and black holes in beyond Horndeski gravity
Hyat Huang, Jutta Kunz, Rashmi Uniyal +1
We investigate the geodesic structure and optical appearance of compact objects with primary scalar hair in shift- and parity-symmetric beyond Horndeski gravity. The analytic solut…
Boson Stars surrounded by Polish Doughnuts in Scalar-Tensor Theory
Kristian Gjorgjieski, Maxim Rose, Burkhard Kleihaus +2
We investigate thick accretion disks (Polish Doughnuts) around rotating self-interacting boson stars in general relativity and scalar-tensor theories, focusing on spontaneously sca…
Matter Accumulations and Accretion Tori around Wormholes
Kristian Gjorgjieski, Jutta Kunz, Petya Nedkova
We study circular orbits and accretion structures around symmetric wormholes. As exemplary solutions we choose three different wormhole spacetimes, namely rotating traversable worm…
Circular Orbits and Photon Orbits at Wormhole Throats
Kristian Gjorgjieski, Jutta Kunz, Petya Nedkova
In this work we study timelike circular orbits and photon orbits at the throat of stationary and axisymmetric wormholes. Our minimal requirements on the spacetime are the existence…