%0 Journal Article
%T The First Acoustics Peak CMBR and Cosmic Total Density
%A De-Hai Zhang
%J Physics
%D 2000
%I arXiv
%X Boomerang measured the first peak in CMBR to be at location of $l_D=196\pm 6$, which excites our strong interesting in it. A widely cited formula is $l_D\simeq 200\Omega_T^{-0.50}$ to estimate the cosmic total density. Weinberg shows it is not correct and should be $l_D\propto \Omega_T^{-1.58}$ near the interest point $(\Omega_m,\Omega_\Lambda)=(0.3,0.7)$. We show further that it should be $l_D\propto \Omega_T^{-1.43}\Omega_m^{-0.147}$ or $\Omega_T^{-1.92}\Omega_\Lambda^{0.343}$ near the same point in the more veracious sense if we consider the effect from the sound horizon. We draw a contour graph for the peak location, show that the recent data favor to a closed universe with about $\Omega_T\simeq 1.03$. If we insist on obtaining a flat universe, a point $(0.36,0.64)$, i.e., more matter and less vacuum energy, is still possible, which has a more right-side first peak $l_D=208$ in CMBR and a smaller acceleration parameter $-q_0=0.10$ for the $z=0.4$ redshift SNIa.
%U http://arxiv.org/abs/astro-ph/0007218v1