I am a leader of the high-energy astrophysics group which works on accreting black holes and neutron stars. We develop atmosphere models for rapidly rotating neutron stars in low-mass X-ray binaries with the aim to determine the equation of state (EoS) of cold dense matter of neutron stars and to understand the physics of accretion in these objects. We also construct atmosphere models for rotation-powered millisecond pulsars that are used by the NICER team to constrain the EoS. We work on hydrodynamical models of boundary/spreading layers on weakly magnetized neutron stars to understand the nature of kHz quasi-periodic oscillations. We also study X-ray pulsars and ultra-luminous X-ray pulsars, both observationally and theoretically. We construct models for the accretion column and for the accretion disc around magnetized neutron stars as well as monitor the sources to study the transition to the propeller regime to measure the neutron stars magnetic field.
Another direction of research is accreting black holes of all scales. We model broadband spectra and timing properties of accreting black holes both in the optical/infrared and the X-rays. We are also doing optical polarimetric studies with the in-house built high-precision DIPol-2 and DIPol-Ultra Fast (UF) polarimeters with the aim to determine the accreting black hole emission mechanisms. The group uses both ground-based ESO VLT and the Nordic Optical Telescope (NOT) as well as space telescopes (XMM-Newton, Chandra, RXTE, INTEGRAL, Fermi, Swift, NuSTAR, SRG). We are also involved in preparation for the new X-ray missions being science group members of the NASA’s Imaging X-ray Polarimeter Explorer (IXPE) and of the Chinese enhanced X-ray Timing and Polarimetry (eXTP) missions. In particular, we develop models for X-ray polarization from X-ray millisecond pulsars and accretion discs around compact objects, accounting for relativistic motion of the emission region.