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Possible detection of signatures of structure formation at the end of the dark age epoch (z~40-20) is examined. We discuss the spectral-spatial fluctuations in the CMBR temperature produced by elastic resonant scattering of CMBR photons on HD molecules located in protostructures moving with peculiar velocity. Detailed chemical kinematic evolution of HD molecules in the expanding homogeneous medium is calculated. Then, the HD abundances are linked to protostructures at their maximum expansion, whose properties are estimated by using the top-hat spherical approach and the LambdaCDM cosmology. We find that the optical depths in the HD three lowest pure rotational lines for high-peak protohaloes at their maximum expansion are much higher than those in LiH molecule. The corresponding spectral-spatial fluctuation amplitudes however are probably too weak as to be detected by current and forthcoming millimeter-telescope facilities. We extend our estimates of spectral-spatial fluctuations to gas clouds inside collapsed CDM haloes by using results from a crude model of HD production in these clouds. The fluctuations for the highest-peak CDM haloes at redshifts ~20-30 could be detected in the future. Observations will be important to test model predictions of early structure formation in the universe.
Gravitational wave detection in space promises to open a new window in astronomy to study the strong field dynamics of gravitational physics in astrophysics and cosmology. The present article is an extract of a report on a feasibility study of gravit
Solitons formation through classical dynamics of two scalar fields with the potential having a saddle point and one minimum in (2+1)-space-time is discussed. We show that under certain conditions in the early Universe both domain walls and strings ca
Young massive clusters (YMCs) are usually accompanied by lower-mass clusters and unbound stars with a total mass equal to several tens times the mass of the YMC. If this was also true when globular clusters (GCs) formed, then their cosmic density imp
Cooling is the main process leading to the condensation of gas in the dark matter potential wells and consequently to star and structure formation. In a metal-free environment, the main available coolants are H, He, H$_2$ and HD; once the gas is enri
This submission has been withdrawn by arXiv administrators because it is a duplicate of 0704.2182.