  If the gas in filaments and halos shares the same velocity field than the
luminous matter, it will generate measurable temperature anisotropies due to
the Kinematic Sunyaev-Zeldovich effect. We compute the distribution function of
the KSZ signal produced by a typical filament and show it is highly
non-gaussian. The combined contribution of the Thermal and Kinematic SZ effects
of a filament of size $L\simeq 5$Mpc and electron density $n_e\simeq
10^3m^{-3}$ could explain the cold spots of $\delta\sim -200\mu$K on scales of
30' found in the Corona Borealis Supercluster by the VSA experiment. PLANCK,
with its large resolution and frequency coverage, could provide the first
evidence of the existence of filaments in this region. The KSZ contribution of
the network of filaments and halo structures to the radiation power spectrum
peaks around $l\sim 400$, a scale very different from that of clusters of
galaxies, with a maximum amplitude $l(l+1)C_l/2\pi\sim 10-25 (\mu K)^2$,
depending on model parameters, i.e., $\sigma_8$ and the Jeans length. About 80%
of the signal comes from filaments with redshift $z\le 0.1$. Adding this
component to the intrinsic Cosmic Microwave Background temperature anisotropies
of the concordance model improves the fit to WMAP 3yr data by
$\Delta\chi^2\simeq 1$. The improvement is not statistically significant but a
more systematic study could demonstrate that gas could significantly contribute
to the anisotropies measured by WMAP.

Astrophysics