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OATS-DAUT SEMINAR
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Speaker:
Fabrizio Nicastro (INAF/Oss. Astr. Monteporzio)
Title:
The Missing Baryon Hunt
Date: Wednesday, November 21th, 2007
Time: 12:00
Venue: Villa Bazzoni
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Abstract:
Despite recent progress in cosmology in assaying the composition of
the energy-mass budget of the Universe, within the framework of our
Standard Cosmological Model (SCM), very little is still known about
nature and origin of 95 % of these constituents: dark Energy and dark
Matter. These have the name 'dark' mainly to label our inability to
directly detect and identify them. Less well known is that the
situation is only conceptually better for the remaining 5 % of Omega:
these are baryons, i.e. the constituents of the ordinary matter of
which stars, planets, and ourselves are made. Today we can account for
less than 50% of the baryons that the SCM predicts, implying that at
least 50 % of the baryons are now missing. Finding and counting these
baryons is therefore vital to our understanding of the Universe, and a
necessary condition to validate the SCM. After a brief introduction
of the problem, I will review all the different and independent pieces
of evidence for these baryons, and will show that the majority of them
is indeed still missing. In the second part of my talk I will then try
to identify new promising lines of research, which will hopefully
allow us in the near future to hone our techniques of hunt and to
converge toward a possible solution of this important and still open
astrophysical problem.
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contact: Pierluigi Monaco (DAUT)