199 citations · 631 across the 22 of their papers we have counts for
22 papers
Chi-square test of the relativistic precession model through the neutron star IGR J17511-3057
Ivan Z. Stefanov
The aim of the current paper is to apply the method of Bambi (Bambi, 2015) to a source which contains two or more simultaneous triads of variability components. The joint chi-squar…
Geodesic model complience with the frequencies of the observed X-ray quasi-period oscillations of XTE J1807-294
Radostina Tasheva, Ivan Stefanov
The investigation of the data for quasi-periodic pulsations observed in the X-ray spectra of the accreting millisecond pulsar XTEJ 1807-294 allows some conclusions to be made about…
Video analysis of the damped oscillations of Pohl's pendulum
Ivan Z. Stefanov, Nikolay Denev, Sava Donkov
In this paper problems that arose with the introduction of distance learning in physics at the Technical University of Sofia due to the COVID-19 pandemic and the imposition of vide…
Density distribution function of a self-gravitating isothermal turbulent fluid in the context of molecular clouds ensembles -- III. Virial analysis
S. Donkov, I. Zh. Stefanov, T. V. Veltchev +1
In the present work we apply virial analysis to the model of self-gravitating turbulent cloud ensembles introduced by Donkov \& Stefanov in two previous papers, clarifying some asp…
Density profile of a self-gravitating polytropic turbulent fluid in the context of ensembles of molecular clouds
S. Donkov, I. Zh. Stefanov, T. V. Veltchev +1
We obtain an equation for the density profile in a self-gravitating polytropic spherically symmetric turbulent fluid with an equation of state . This is don…
Density distribution function of a self-gravitating isothermal compressible turbulent fluid in the context of Molecular Clouds ensembles II: the contribution of the turbulent term and the potential of the outer shells
Sava Donkov, Ivan Zh. Stefanov
In this paper we continue to investigate the energy conservation equation obtained in our previous work. We set ourselves three new goals. The first one is to rewrite the main equa…