Abstract Details
| Name: Louise Rebecca Affiliation: Christ Junior College, Bangalore Conference ID: ASI2019_35 Title : Dark matter density distributions and dark energy constraints on structure formation Authors and Co-Authors : Louise Rebecca Kenath Arun C Sivaram Abstract Type : Poster Abstract Category : General Relativity and Cosmology Abstract : It was shown recently that the size of gravitationally bound large scale structures can be limited from the requirement that their gravitational binding self-energy density should at least be equal to the background repulsive dark energy density. This requirement for large scale cosmic structures implies a mass-radius relation for M/R^2, which is of the order of 1 g/cm^2, as pointed out earlier. This relation seems to hold true for primeval galaxies as well as those at the present epoch. The universality of the M/R^2 relation can be suggestive of the evolution of dark energy and can set constraints on the nature and evolution of dark energy. It appears that dark energy has remained constant from the early formation of galaxies, indicating a constant cosmological constant as the background dark energy density. Besides, we also set constraints on the size of galaxy clusters and superclusters due to the repulsive cosmological dark energy. This could indicate why large scale cosmic structures much larger than ∼200 Mpc are not seen. This model can be further extended to incorporate various dark matter density distributions in galaxies and clusters which could set constraints on their sizes which are consistent with observation. We also show that the constraints set using modified Newtonian dynamics (MOND) is again consistent with observations and same as that in the Newtonian case, hence making it impossible to distinguish the two (i.e. Newtonian case with DM and MOND) as pointed out recently. We also point out that the recent observations of baryon-dominated disk galaxies formed about ten billion years ago indicates better consistency of MOND (rather than DM) with observations. |