CMBR anisotropies are fundamentally shaped by cosmological perturbations originating from quantum randomness during the universe's compact phase. While inflation plays a critical role in scaling these perturbations, it is not the sole contributor; baryons, dark matter, neutrinos, and dark energy also influence the initial density fluctuations. The inflaton field transitions into normal matter and radiation as energy density decreases, leading to the formation of structures like stars and planets. This interplay of constituents ultimately drives the expansion of the universe.
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So, what are the 'constituents' of initial density upon which quantum randomness operates?Ibix said:Its source is quantum randomness when the universe was very compact, meaning that the initial density was slightly non-uniform on very small scales.
In the post-inflation universe, do the other constituents of the universe, such as baryons, dark matter, etc., contribute to the anisotropy?Ibix said:This was rapidly scaled up by inflation and later more slowly by expansion to give the medium scale anisotropy we see today
The inflaton field. When the energy density drops low enough this condenses into normal matter and radiation.Ranku said:So, what are the 'constituents' of initial density upon which quantum randomness operates?
Yes - ultimately causing some overdense regions to collapse into stars and planets. And it's its stress-energy in the universe that makes it an expanding universe in the first place.Ranku said:In the post-inflation universe, do the other constituents of the universe, such as baryons, dark matter, etc., contribute to the anisotropy?