Evolution of mass and velocity filed in comic web: comparison between
  baryonic and dark matter
  We investigate the evolution of cosmic web since $z=5$ in grid based
cosmological hydrodynamical simulations, focusing on the mass and velocity
field of both baryonic and cold dark matter. The tidal tensor of density is
used as the main method for web identification, with $\lambda_{th}=0.2-1.2$.
The evolution trends in baryonic and dark matter are similar, while moderate
differences are observed. Sheets appeared early and their large scale pattern
may have been set up by $z=3$. In term of mass, filaments superseded sheets as
the primary collapsing structures at $z\sim2-3$. Tenuous filaments assembled
with each other to form prominent ones at $z<~2$. In accordance with the
construction of the frame of sheets, the cosmic divergence velocity, $v_{div}$,
had been well developed above 2-3 Mpc by z=3. Afterwards, curl velocity,
$v_{curl}$, grown dramatically along with the rising of filaments, become
comparable to $v_{div}$, for $<2-3 Mpc$ at $z=0$. The scaling of $v_{curl}$ can
be described by the hierarchical turbulence model. The alignment between
vorticity and eigenvectors of shear tensor in baryonic matter field resembles
dark matter, and is even moderately stronger between $\vec{\omega}$ and
$\vec{e}_1$, and $\vec{e}_3$. Compared with dark matter, mildly less baryonic
matter is found residing in filaments and clusters, and its vorticity has been
developed more significantly below $2-3 Mpc$. These differences may be
underestimated due to the limited resolution and lack of star formation in our
simulation. The impact of the change of dominant structures in over-dense
regions at $z\sim2-3$ on galaxy formation and evolution is shortly discussed.
