Résumé :
Cosmological observations based on a wide variety of methods are in good
agreement on the contents and history of the universe. The universe
contains roughly 4\% baryons, 23\% of a new kind of matter we hope to
understand with future particle accelerators, and 73\% of a new kind of
effective pressure or energy that has yet to find explanation in
fundamental theories.
In the standard model, quantum fluctuations in the
early universe led to the fluctuations in gravitational potential that
seeded the formation of cosmic structure. The inflation model predict the
spectrum of these fluctuations.
WMAP's measurement of the CMB polarization allows us to break a number of
cosmic parameter degeneracies,measure the spectrum of fluctuations, and
begin to test specific models of inflation.
In other words, through measurements of the CMB, we have begun testing the
physics of quantum fluctuations in the universe when it was less than
$10^{-20}$ seconds old.
We discuss the WMAP results with an emphasis on aspects of the measurement
that directly impact the determination of the spectrum of fluctuations.
