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On general features of warm dark matter with reduced relativistic gas
- Source :
- European Physical Journal, European Physical Journal C: Particles and Fields, Vol 78, Iss 5, Pp 1-13 (2018)
- Publication Year :
- 2017
- Publisher :
- arXiv, 2017.
-
Abstract
- Reduced Relativistic Gas (RRG) is a useful approach to describe the warm dark matter (WDM) or the warmness of baryonic matter in the approximation when the interaction between the particles is irrelevant. The use of Maxwell distribution leads to the complicated equation of state of the J\"{u}ttner model of relativistic ideal gas. The RRG enables one to reproduce the same physical situation but in a much simpler form. For this reason RRG can be a useful tool for the theories with some sort of a "new Physics". On the other hand, even without the qualitatively new physical implementations, the RRG can be useful to describe the general features of WDM in a model-independent way. In this sense one can see, in particular, to which extent the cosmological manifestations of WDM may be dependent on its Particle Physics background. In the present work RRG is used as a complementary approach to derive the main observational exponents for the WDM in a model-independent way. The only assumption concerns a non-negligible velocity $v$ for dark matter particles which is parameterized by the warmness parameter $b$. The relatively high values of $b$ ( $b^2\gtrsim 10^{-6}$) erase the radiation (photons and neutrinos) dominated epoch and cause an early warm matter domination after inflation. Furthermore, RRG approach enables one to quantify the lack of power in linear matter spectrum at small scales and in particular, reproduces the relative transfer function commonly used in context of WDM with accuracy of $\lesssim 1\%$. A warmness with $b^2\lesssim 10^{-6}$ (equivalent to $v\lesssim 300 km/s$) does not alter significantly the CMB power spectrum and is in agreement with the background observational tests.<br />Comment: 15 pages, 8 figures. Essential improvements in style and presentation
- Subjects :
- Inflation (cosmology)
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Physics and Astronomy (miscellaneous)
010308 nuclear & particles physics
Equation of state (cosmology)
Physics beyond the Standard Model
Cosmic microwave background
Dark matter
Spectral density
FOS: Physical sciences
lcsh:Astrophysics
Context (language use)
General Relativity and Quantum Cosmology (gr-qc)
01 natural sciences
General Relativity and Quantum Cosmology
Theoretical physics
lcsh:QB460-466
0103 physical sciences
Warm dark matter
lcsh:QC770-798
lcsh:Nuclear and particle physics. Atomic energy. Radioactivity
010303 astronomy & astrophysics
Engineering (miscellaneous)
Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- ISSN :
- 14346044
- Database :
- OpenAIRE
- Journal :
- European Physical Journal, European Physical Journal C: Particles and Fields, Vol 78, Iss 5, Pp 1-13 (2018)
- Accession number :
- edsair.doi.dedup.....abdd80f14978d600d1dedc5a031f2787
- Full Text :
- https://doi.org/10.48550/arxiv.1706.08595