We generalize quintom to include the tachyonic kinetic term along with the classical one. For the spatially flat, homogeneous and isotropic Universe with Friedmann-Robertson-Walker metric of 4-space we discuss in detail the reconstruction of the scalar fields potential $U(\phi,\xi)$. Such a reconstruction cannot be done unambiguously, so we consider 3 simplest forms of $U(\phi,\xi)$: the...
The 3.5 keV line, discovered in early 2014 in the spectra of different cosmic objects, draws large attention as being the dark matter signal candidate. Much effort was performed since then to determine it's nature. The one conclusion to point out is that the dark matter signal is by now the only explanation consistent with all the observational data available.
We are presenting the detection...
Recent report of 21-cm absorption signal by EDGES experiment has raised considerable interest in the dark matter (DM) community. Taking the reported EDGES result at face value, a number of forthcoming papers constrained masses of DM particles and their interaction strengths with Standard Model particles.
However, the connection between the formation of structures and 21-cm signal requires...
We present the $K-T$ scaling relation of the individual galaxies (mostly early-type galaxies), groups, and clusters. The given relation is based on 168 targets observed with $Chandra$ X-ray Observatory. We derive entropy at $R_{2500}$ and build $K_{2500}-T$ relation covering 0.3 -- 15.0 keV of temperature and 10$^{12}$ -- 10$^{15} M_{\odot}$ of total mass bands. We find that entropy at...
It is known that the Bose-Einstein condensate (BEC) based Dark Matter (DM) model solves several problems of Cold Dark Matter model on the small scales, including core-cusp problem. In turn, there are some difficulties that arise in the framework of BEC DM, like overestimated a bit (up to 20%) prediction of halo mass in comparison with the values derived from observations. In ref. [1], the...
