Dark Neutrinos

A. Nicolaidis

Theoretical Physics Department, University of Thessaloniki, Thessaloniki, Greece.

DOI: 10.4236/jmp.2012.312247                

Abstract

Solar, atmospheric and reactor neutrino experiments established that neutrinos are massive. It is quite natural then to consider neutrinos as candidate particles for explaining the dark matter in halos around galaxies. We study the gravitational clustering of these neutrinos within a model of a massive core and a surrounding spherical neutrino halo. The neutrinos form a degenerate Fermi gas and a loaded polytropic equation is established. We solve the equation and we obtain the neutrino density in a galaxy, the size of the galaxy and the galactic rotational curves. The available data favor a neutrino with a mass around 10 eV. The consequent cosmological implications are examined.

Keywords

Neutrinos; Neutrino Mass; Gravitational Clustering; Dark Matter; Polytrope Equation

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	A. Romanino, “Neutrino Physics,” CERN Yellow Report CERN-2012-001, pp. 153-182.
[2]	A. Strumia and F. Vissani, “Neutrino Masses and Mixings and…,” arXiv:hep-ph/0606054.
[3]	C. Giunti, “Phenomenology of Sterile Neutrinos,” arXiv: 1110.3914 [hep-ph].
[4]	N. Mavromatos, “Neutrinos and the Universe,” Invited Paper to NUFACT11, arXiv:1110.3729 [hep-ph].
[5]	C. Tao, “Astrophysical Constraints on Dark Matter,” arXiv: 1110.0298.
[6]	H. de Vega and N. Sanchez, “Highlights and Conclusions of the Chalonge Workshop 2011,” arXiv:1109.3187 [astro-ph.CO].
[7]	A. Dolgov, “Cosmological Implications of Neutrinos,” Surveys High Energy Physics, Vol. 17, No. 1-4, 2002, pp. 91-114. doi:10.1080/0124421021000054202
[8]	M. Zombeck, “Handbook of Space, Astronomy and Astrophysics,” Cambridge University Press, Cambridge, 1990.
[9]	S. Chandrasekhar, “Stellar Structure,” University of Chicago Press, Chicago, 1939.
[10]	L. Landau and E. Lifshitz, “Statistical Physics,” Addison-Wesley Publishing Co., Boston, 1969.
[11]	J. Huntley and W. Saslaw, “The Distribution of Stars in Galactic Nuclei: Loaded Polytropes,” Astrophysical Journal, Vol. 199, 1975, pp. 328-335. doi:10.1086/153695
[12]	R. Viollier, F. Leimgruber and D. Trautmann, “Halos of Heavy Neutrinos around Baryonic Stars,” Physics Letters B, Vol. 297, No. 1-2, 1992, pp. 132-137. doi:10.1016/0370-2693(92)91081-J
[13]	R. Viollier, D. Trautmann and G. Tupper, “Supermassive Neutrino Stars and Galactic Nuclei,” Physics Letters, Vol. 306, No. 1-2, 1993, pp. 79-85.
[14]	V. Rubin, W. Kent Ford Jr. and N. Thonnard, “Extended Rotation Curves of High-Luminosity Spiral Galaxies. IV-Systematic Dynamical Properties, SA through SC,” Astrophysical Journal, Vol. 225, No. 1, 1978, pp. L107- L111.
[15]	R. Cowsik and J. McClelland, “Gravity of Neutrinos of Nonzero Mass in Astrophysics,” Astrophysical Journal, Vol. 180, 1973, pp. 7-10. doi:10.1086/151937
[16]	R. Cowsik, “The Neutrino Hypothesis for Dark Matter in Dwarf Spheroidals,” Journal of Astrophysics and Astronomy, Vol. 7, No. 1, 1986, pp. 1-6. doi:10.1007/BF02715021
[17]	T. Nieuwenhuizen, “Do Non-Relativistic Neutrinos Constitute the Dark Matter?” Europhysics Letters, Vol. 86, No. 3, 2009, Article ID: 59001.
[18]	P. Langacker, J. Leveille and J. Sheiman, “On the Detection of Cosmological Neutrinos by Coherent Scattering,” Physical Review D, Vol. 27, No. 6, 1983, pp. 1228-1242. doi:10.1103/PhysRevD.27.1228
[19]	J. Hamann, S. Hannestad, G. Raffelt and Y. Wong, “Sterile Neutrinos with eV Masses in Cosmology—How Disfavoured Exactly?” Journal of Cosmology and Astroparticle Physics, No. 9, 2011, arXiv:1108.4136.
[20]	H. de Vega and N. Sanchez, “Model-Independent Analysis of Dark Matter Points to a Particle Mass at the keV Scale,” Monthly Notices of the Royal Astronomical Society, Vol. 404, No. 2, 2010, pp. 885-894. doi:10.1111/j.1365-2966.2010.16319.x
[21]	P. Biermann and A. Kusenko, “Relic keV Sterile Neutrinos and Reionization,” Physical Review Letters, Vol. 96, No. 9, 2006, Article ID: 091301. doi:10.1103/PhysRevLett.96.091301