317 citations · 479 across the 15 of their papers we have counts for
16 papers
Neutron Stars in Causal Scalar-Tensor Theories
Mark P. Hertzberg, Oleksandr S. Stashko
We study static, spherically symmetric neutron stars in a class of scalar-tensor theories with non-canonical kinetic terms (K-essence) obeying all causality and hyperbolicity condi…
Spherically symmetric configurations in the quadratic gravity
V. I. Zhdanov, O. S. Stashko, Yu. V. Shtanov
We study spherically symmetric configurations of the quadratic gravity in the Einstein frame. In case of a purely gravitational system, we have determined the global qualita…
Quasi-normal modes of naked singularities in presence of non-linear scalar fields
O. S. Stashko, O. V. Savchuk, V. I. Zhdanov
We study linear perturbations against static spherically symmetric background configurations of General Relativity with a real scalar field (SF), which is minimally coupled with gr…
Pion stars embedded in neutrino clouds
O. S. Stashko, O. V. Savchuk, L. M. Satarov +3
We study self-gravitating multi-pion systems (pion stars) in a state of the Bose condensate. To ensure stability of such stars, it is assumed that they are immersed in the lepton b…
Circular orbits of test particles interacting with massless linear scalar field of the naked singularity
O. S. Stashko, V. I. Zhdanov
We study effects of the particles coupling with scalar field (SF) on the distribution of stable circular orbits (SCO) around the naked singularity described by the well-known Fishe…
Critical point influenced by Bose-Einstein condensation
V. A. Kuznietsov, O. Savchuk, O. S. Stashko +1
A system of bosons studied within the mean field framework has two fascinating phenomena: a liquid-gas first order phase transition and Bose-Einstein condensation. Interplay betwee…