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Abstract: In the standard Lambda CDM cosmological model with a Gaussian primordialdensity fluctuation field, the relatively low value of the mass varianceparameter sigma 8=0.74{+0.05}{-0.06}, obtained from the WMAP 3-year dataresults in a reduced likelihood that the measured level of CMB anisotropy onthe scales of clusters is due to the Sunyaev-Zeldovich S-Z effect. To assessthe feasibility of producing higher levels of S-Z power, we explore twoalternative models which predict higher cluster abundance. In the first modelthe primordial density field has a chi^2 1 distribution, whereas in the secondan early dark energy component gives rise to the desired higher clusterabundance. We carry out the necessary detailed calculations of the levels ofS-Z power spectra, cluster number counts, and angular 2-point correlationfunction of clusters, and compare in a self-consistent way their predictedredshift distributions. Our results provide a sufficient basis upon which theviability of the three models may be tested by future high qualitymeasurements.



Author: S. Sadeh, Y. Rephaeli, J. Silk

Source: https://arxiv.org/







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