Do we need soft cosmology?
We examine the possibility of “soft cosmology”, namely small deviations from the usual framework due to the effective appearance of soft-matter properties in the Universe sectors. One effect of such a case would be the dark energy to exhibit a different equation-of-state parameter at large scales (w...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-11-01
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| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S037026932100589X |
| _version_ | 1831761486468349952 |
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| author | Emmanuel N. Saridakis |
| author_facet | Emmanuel N. Saridakis |
| author_sort | Emmanuel N. Saridakis |
| collection | DOAJ |
| description | We examine the possibility of “soft cosmology”, namely small deviations from the usual framework due to the effective appearance of soft-matter properties in the Universe sectors. One effect of such a case would be the dark energy to exhibit a different equation-of-state parameter at large scales (which determine the universe expansion) and at intermediate scales (which determine the sub-horizon clustering and the large scale structure formation). Concerning soft dark matter, we show that it can effectively arise due to the dark-energy clustering, even if dark energy is not soft. We propose a novel parametrization introducing the “softness parameters” of the dark sectors. As we see, although the background evolution remains unaffected, due to the extreme sensitivity and significant effects on the global properties even a slightly non-trivial softness parameter can improve the clustering behavior and alleviate e.g. the fσ8 tension. Lastly, an extension of the cosmological perturbation theory and a detailed statistical mechanical analysis, in order to incorporate complexity and estimate the scale-dependent behavior from first principles, is necessary and would provide a robust argumentation in favour of soft cosmology. |
| first_indexed | 2024-12-22T04:48:30Z |
| format | Article |
| id | doaj.art-deb0d5537fa04265b49ca4066de56250 |
| institution | Directory Open Access Journal |
| issn | 0370-2693 |
| language | English |
| last_indexed | 2024-12-22T04:48:30Z |
| publishDate | 2021-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj.art-deb0d5537fa04265b49ca4066de562502022-12-21T18:38:32ZengElsevierPhysics Letters B0370-26932021-11-01822136649Do we need soft cosmology?Emmanuel N. Saridakis0National Observatory of Athens, Lofos Nymfon, 11852 Athens, Greece; Department of Astronomy, School of Physical Sciences, University of Science and Technology of China, Hefei 230026, PR China; Correspondence to: National Observatory of Athens, Lofos Nymfon, 11852 Athens, Greece.We examine the possibility of “soft cosmology”, namely small deviations from the usual framework due to the effective appearance of soft-matter properties in the Universe sectors. One effect of such a case would be the dark energy to exhibit a different equation-of-state parameter at large scales (which determine the universe expansion) and at intermediate scales (which determine the sub-horizon clustering and the large scale structure formation). Concerning soft dark matter, we show that it can effectively arise due to the dark-energy clustering, even if dark energy is not soft. We propose a novel parametrization introducing the “softness parameters” of the dark sectors. As we see, although the background evolution remains unaffected, due to the extreme sensitivity and significant effects on the global properties even a slightly non-trivial softness parameter can improve the clustering behavior and alleviate e.g. the fσ8 tension. Lastly, an extension of the cosmological perturbation theory and a detailed statistical mechanical analysis, in order to incorporate complexity and estimate the scale-dependent behavior from first principles, is necessary and would provide a robust argumentation in favour of soft cosmology.http://www.sciencedirect.com/science/article/pii/S037026932100589X |
| spellingShingle | Emmanuel N. Saridakis Do we need soft cosmology? Physics Letters B |
| title | Do we need soft cosmology? |
| title_full | Do we need soft cosmology? |
| title_fullStr | Do we need soft cosmology? |
| title_full_unstemmed | Do we need soft cosmology? |
| title_short | Do we need soft cosmology? |
| title_sort | do we need soft cosmology |
| url | http://www.sciencedirect.com/science/article/pii/S037026932100589X |
| work_keys_str_mv | AT emmanuelnsaridakis doweneedsoftcosmology |