A History of Dark Matter

Singlet scalar dark matter in noncommutative space

In this paper, we examine the singlet scalar dark matter annihilation to becoming the Standard Model particles in the non-commutative space. In the recent decades, many candidates of dark matter have been offered,  but our information about  the nature of dark matter is still limited. There are such particle candidates as  scalar matetr, fermion, boson, gauge boson, etc.; however, they have nei...

Formation of Large Structures in the Acceleration Universe with a Hybrid Expansion Law

In the current paper, we have studied the effect of dark energy on for-mation where dark energy exists in the background. For this purpose, we used both WMAP9 and Planck data to study how the radius changes with redshift in these mod-els. We used different data sets to fix the cosmological parameters to obtain a solution for a spherical region under collapse. The mechanism of structure formation f...

Dark Chocolate and Metabolic Syndrome; Do Polyphenols All that Matter?

Black Holes as Dark Matter

While the energy of the universe has been established to be about 0.04 baryons, 0.24 dark matter and 0.72 dark energy, the cosmological entropy is almost entirely, about (1−10), from black holes and only 10 from everything else. This identification of all dark matter as black holes is natural in statistical mechanics. Cosmological history of dark matter is discussed. [email protected]

Does stellar mass assembly history vary with environment?

Using the publicly available VESPA database of SDSS Data Release 7 spectra, we calculate the stellar Mass Weighted Age (hereafter MWA) as a function of local galaxy density and dark matter halo mass. We compare our results with semi-analytic models from the public Millennium Simulation. We find that the stellar MWA has a large scatter which is inherent in the data and consistent with that seen ...