The Hot Dark Matter

dc.creatorCaldwell, David O.
dc.date1999-10-14
dc.date.accessioned2026-07-07T04:08:21Z
dc.date.available2026-07-07T04:08:21Z
dc.descriptionThere is a puzzling contradiction: direct observations favor a low-mass-density universe ($0.2\leΩ_m\le0.6$), but the only model which fits universe structure over more than three orders of magnitude in distance scale has a mix of hot (neutrino) and cold dark matter providing a critical density universe. Models of an open universe (low $Ω_m$) or one adding a cosmological constant ($Λ$) to provide a critical energy density ($Ω_m+ Ω_Λ=1$) have probabilities of $<10^{-3}$. Two-neutrino dark matter works better than having the needed $\sim5$ eV of neutrino mass in one species of neutrino, and this is consistent with the only model which fits all present indications for neutrino mass: $ν_μ\toν_τ$ accounting for the atmospheric anomaly (with $ν_μ$ and $ν_τ$ being the hot dark matter), $\barν_μ\to\barν_e$ being observed by LSND, and $ν_e\toν_s$ explaining the solar $ν_e$ deficit. The LSND/KARMEN results are consistent with the needed mass of hot dark matter. Further support for this mass pattern is provided by the need for the sterile neutrino, $ν_s$, to make possible heavy-element nucleosynthesis in supernovae. It is a fascinating question as to whether the hot dark matter paradox will be resolved by better measurements or by the introduction of new physics.
dc.description10 pages, 1 figure, talk given at 23rd Johns Hopkins Workshop, "Neutrinos in the Next Millenium"
dc.identifierhttps://arxiv.org/abs/hep-ph/9910349
dc.identifierhttp://arxiv.org/abs/hep-ph/9910349
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/49499
dc.subjectHigh Energy Physics - Phenomenology
dc.titleThe Hot Dark Matter
dc.typetext

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