The discussion revolves around the origins of cosmological perturbations and their relationship to Cosmic Microwave Background Radiation (CMBR) anisotropies. Participants explore whether inflation is the sole contributor to these perturbations or if other components such as baryons, dark matter, neutrinos, and dark energy also play a role. The conversation touches on theoretical aspects of cosmology.
Participants do not reach a consensus on the sole source of cosmological perturbations, with multiple competing views regarding the roles of inflation and other constituents of the universe remaining evident throughout the discussion.
The discussion reflects theoretical considerations and does not resolve the complexities surrounding the contributions of various components to CMBR anisotropies. Assumptions about the nature of quantum randomness and the role of the inflaton field are not fully explored.
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?