QCD Equation of State and Dark Matter
نویسنده
چکیده
The QCD equation of state is not often discussed in cosmology. However, the relic density of weakly interacting massive particles (WIMPs) depends on the entropy and the expansion rate of the Universe when they freeze out, at a temperature in the range 400 MeV – 40GeV, where QCD corrections are still important. We use recent analytic and lattice calculations of the QCD pressure to produce a new equation of state suitable for use in relic density calculations. As an example, we show that relic densities calculated by the dark matter package DarkSUSY receive corrections of several per cent, within the observational accuracy of the Planck CMB mission, due for launch in 2007.
منابع مشابه
Dark matter of weakly interacting massive particles and the QCD equation of state
1550-7998=20 Weakly Interacting Massive Particles (WIMPs) of mass m freeze-out at a temperature Tf ’ m=25, i.e. in the range 400 MeV– 40 GeV for a particle in the typical mass range 10–1000 GeV. The WIMP relic density, which depends on the effective number of relativistic degrees of freedom at Tf, may be measured to better than 1% by Planck, warranting comparable theoretical precision. Recent t...
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