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Abstract

We show that the amplitude of the second acoustic peak in the newly released BOOMERANG-98 and MAXIMA-I data is compatible with the standard primordial nucleosynthesis and with the locally broken scale-invariant matter power spectrum suggested by recent measurements of the power spectrum in the range 20È200 h~1 Mpc. If the slope of matter density perturbations on large scales is n B 1, the Hubble constant is 0.5 \ h \ 0.75, and rms mass Ñuctuations at 8 h~1 Mpc are then 0.65 ¹ p 8 ¹ 0.75, for a universe approximately 14 Gyr old, our best Ðt within the nucleosynthesis bound ) B h2 \ 0.019 0.0024 requires Cluster abundances further constrain the matter density to be 0.3 ¹ ) m ¹ 0.5. ) m B 0.3. The CMB data alone are not able to determine the detailed form of the matter power spectrum in the range 0.03 \ k \ 0.06 h Mpc~1, in which deviations from the scale-invariant spectrum are expected to be most signiÐcant, but they do not contradict the existence of the previously claimed peak at k D 0.05 h Mpc~1 and a depression at k D 0.035 h Mpc~1. (Bond et al. 2000a) that supported the l \ l max \ 212^7 idea of an approximately spatially Ñat universe with a cosmological constant (vacuum energy) and nonbaryonic cold dark matter (CDM). However, rather unexpectedly, the second acoustic peak at l D 500È550 appeared to have a low amplitude (especially in the B00 data). Another unexpected feature was a shift of the Ðrst peak to smaller l than the standard theoretical prediction for the Ñat l The former result is mainly the consequence of the low amplitude of the second acoustic peak, while the latter is caused mostly by the shift of the Ðrst peak to the left. These conclusions persist if additional information on the largescale structure (LSS) of the universe, as the density Ñuctua-tion parameter and the shape of the power spectrum of p 8 , matter are taken into account. In particular, the most exhaustive of these e †orts made by Tegmark, Zaldarriaga, & Hamilton (2000), who performed an 11 parameter Ðt to the current CMB and LSS data, has led to essentially the same result about the high baryon density. To avoid contradiction with the standard BBN, a number of drastic changes in the standard FRW cosmology were proposed, such as leptonic asymmetry ( Vol. 559