We investigate the statistical properties of cosmic baryon fluid in the nonlinear regime, which is crucial for understanding the large-scale structure formation of the Universe. With the hydrodynamic simulation sample of the Universe in the cold dark matter model with a cosmological constant, we show that the intermittency of the velocity field of cosmic baryon fluid at redshift $z=0$ in the scale range from the Jeans length to about $16{\mathrm{h}}^{-1}\mathrm{Mpc}$ can be extremely well described by She-Leveque’s universal scaling formula. The baryon fluid also possesses the following features: (1) for volume weight statistics, the dissipative structures are dominated by sheets, and (2) the relation between the intensities of fluctuations is hierarchical. These results imply that the evolution of highly evolved cosmic baryon fluid is similar to a fully developed turbulence.

• Received 2 July 2005

DOI:https://doi.org/10.1103/PhysRevLett.96.051302