Cosmological Parameters and Black Holes
  This work is related to different questions within cosmology. The principal idea herein is to develop cosmological knowledge making use of the analyses of observational data in order to find the values of the matter density Omega_m and vacuum energy density Omega_Lambda.   Data fitting is carried out using two statistical methods, chi^2 and maximum likelihood. The data analysis exhibits that a low density and flat Universe is strongly favoured.   Applying the Omega_m value found for clusters of galaxies, we demonstrate that clusters have very little room for baryonic dark matter. An upper limit to the small but non-negligible sum of baryonic dark matter and galaxy mass can be estimated, requiring the use of special statistics.   A Toroidal Black Hole (TBH) study, in contrast to the Spherical Black Hole (SBH), shows that the TBH can be used as an important tool in explaining AGN phenomena. 
S. M. Harun-or-Rashid (University of Helsinki, Finland)