What is dark matter How is it formed?

Answer 1

Dark matter is the term used to describe the hypothetical type of non-baryonic matter rationalized to account for discrepancies between the mass of large astronomical objects, determined from their gravitational effects, and the mass calculated from the "luminous matter" that they contain: i.e. stars, gas and dust. Since there are no empirical evidence to support dark matter, by process of elimination, based in part on the calculations consistent with general relativity, dark matter is estimated to constitute 84.5% of the total matter in the universe. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.

Although the existence of dark matter is generally accepted by the mainstream scientific community, there is no generally agreed direct detection of it. Other theories including MOND and TeVeS, are some alternative theories of gravity proposed to try to explain the anomalies for which dark matter is intended to account. Due to a lack of empirical evidence, there is are no theoretical conjectures for the formation of dark matteras part ofthe Big Bang event.

Other Opinion: From an alternate perspective, dark energy is thought to be the original medium of a pre-Big Bang universe. Consequently the Big Bang creation event, via an unfolding of its condition from singularity, introduce the intrusion of our existence: a reality of positive density matter within a traditional fourth dimensional SpaceTime continuum. Considering a pre-Big Bang universe as zero density matter, the intrusion of positive density matter simultaneously provided for introduction of negative density matter (or dark matter). The resulting effect of bringing the universe back into the more ordered condition consistent with its pre-Big Bang persistence is the expanding of the positive density matter within our fourth dimensional universe.