A Coarse-Grained Field Theory for Density Fluctuations and Correlation Functions of Galactic Objects

الأصل · EN

We present a coarse-grained field theory of density fluctuations for a Newtonian self-gravitating many-body system and apply it to a homogeneous Universe with small density fluctuations. The theory treats the clustering of galaxies and clusters in terms of the field of density fluctuations. The Jeans length λ₀, a unique physical scale for a gravitating system, appears naturally as the characteristic scale underlying the large scale structure. Under Gaussian approximation the analytic expressions of ξ(r) and P(k) are obtained. The correlation amplitude is proportional to the galactic mass, and is oscillating over large scales 100 h⁻¹ Mpc and damped to zero. The spectrum amplitude is inversely proportional to the galactic number density.The preliminary results qualitatively explain some pronounced features of large scale structures.