39 citations · 137 across the 16 of their papers we have counts for
16 papers
Perturbation theory for gravitational shadows in Kerr-like spacetimes
Kirill Kobialko, Dmitri Gal'tsov
We present a fully analytical method for calculating the key parameters of a Kerr-like gravitational shadow, including its horizontal and vertical diameters, and , the c…
Gravitational shadow and emission spectrum of thin accretion disks in a plasma medium
Kirill Kobialko, Dmitri Gal'tsov, Alexey Molchanov
In anticipation of future multi-frequency observations of black hole with the Next Generation Event Horizon Telescope (ngEHT), we construct spectral images of a thin accretion disk…
Perturbation theory for gravitational shadows in static spherically symmetric spacetimes
Kirill Kobialko, Dmitri Gal'tsov
We develop a perturbation theory for surfaces confining photons and massive particles in static spherically symmetric spacetimes in terms of two parameters: the mass-to-energy rati…
Uniqueness of the static vacuum asymptotically flat spacetimes with massive particle spheres
Kirill Kobialko, Igor Bogush, Dmitri Gal'tsov
In this paper, we establish that a four-dimensional static vacuum asymptotically flat spacetime containing a massive particle sphere is isometric to the Schwarzschild spacetime. Ou…
Constructing massive particles surfaces in static spacetimes
Igor Bogush, Kirill Kobialko, Dmitri Gal'tsov
The procedure for constructing the massive particle surfaces in static space-times is described in detail and the equivalence of the main results with the results of the geodesic a…
Black hole shadows of massive particles and photons in plasma
Kirill Kobialko, Igor Bogush, Dmitri Gal'tsov
Explicitly covariant analytical expressions are derived that describe the boundaries of shadows cast by massive particles scattered by a gravitating object. This covers scenarios w…
Glued massive particles surfaces
Igor Bogush, Kirill Kobialko, Dmitri Gal'tsov
A novel generalization of photon surfaces to the case of massive charged particles is given for spacetimes with at least one isometry, including stationary ones. A related notion o…
The geometry of massive particle surfaces
Kirill Kobialko, Igor Bogush, Dmitri Gal'tsov
We propose a generalization of Claudel, Virbhadra, and Ellis photon surfaces to the case of massive charged particles, considering a timelike hypersurface such that any worldline o…
Photon surfaces, shadows and accretion disks in gravity with minimally coupled scalar field
Igor Bogush, Dmitri Gal'tsov, Galin Gyulchev +3
In this article, we conduct a sequential study of possible observable images of black hole simulators described by two recently obtained rotating geometries in Einstein gravity, mi…
Slice-reducible conformal Killing tensors, photon surfaces and shadows
Kirill Kobialko, Igor Bogush, Dmitri Gal'tsov
We generalize our recent method for constructing Killing tensors of the second rank to conformal Killing tensors. The method is intended for foliated spacetimes of arbitrary dimens…
Photon regions in stationary axisymmetric spacetimes and umbilic conditions
Kirill Kobialko, Dmitri Gal'tsov
We present the fundamentals of the recently proposed geometric description of photon regions in terms of foliation into fundamental photon hypersurfaces, which satisfies the umbili…
Killing tensors in foliated spacetimes and photon surfaces
Kirill Kobialko, Igor Bogush, Dmitri Gal'tsov
We discuss a recently proposed geometric method for constructing a nontrivial Killing tensor of rank two in a foliated spacetime of codimension one that lifts trivial Killing tenso…
Killing tensors and photon surfaces in foliated spacetimes
Kirill Kobialko, Igor Bogush, Dmitri Gal'tsov
We present a purely geometric method for constructing a rank two Killing tensor in a spacetime with a codimension one foliation that lifts the trivial Killing tensors from slices t…
Photon regions and umbilic conditions in stationary axisymmetric spacetimes
K. V. Kobialko, D. V. Gal'tsov
Photon region (PR) in the strong gravitational field is defined as a compact region where photons can travel endlessly without going to infinity or disappearing at the event horizo…
Photon trapping in static axially symmetric spacetime
D. V. Gal'tsov, K. V. Kobialko
Recently, several new characteristics have been introduced to describe null geodesic structure of strong gravitational field, such as photon regions, transversely trapping surfaces…
Completing characterization of photon orbits in Kerr and Kerr-Newman metrics
D. V. Gal'tsov, K. V. Kobialko
Recently, several new characteristics have been introduced to describe null geodesic structure of stationary spacetimes, such as photon regions (PR) and transversely trapping surfa…