2. DARK MATTER
Definition
According to the Planck mission team, and based on the
standard model of cosmology, the total mass-energy of the
known universe contains 4% ordinary matter, 21% dark matter
and 75% dark energy.
3. DARK MATTER
Observational evidences
•Galaxy rotation curves.
•Velocity dispersion of galaxies
•Galaxy clusters and gravitational lensing.
•Cosmic microwave background.
•Sky surveys and baryon acoustic oscillations.
•Type Ia supernovae distance measurements.
•Lyman-alpha forest.
•Structure formation.
•Possible 2014 indirect detection.
4. DARK MATTER
Types depending on baryons
Baryonic: dark matter made of baryons (ordinary matter
including protons and neutrons).
No baryonic: dark matter not made of baryons.
5. DARK MATTER
Problems
What is dark matter?
How is generated?
Is it related to supersymetry?
Supersymetry: is a proposed extension of space-time symmetry that relates two basic
classes of elementary particles: bosons, which have an integer-valued spin, and
fermions, which have a half-integer spin.
6. DARK MATTER
Types depending on length
Cold dark matter: much smaller than a protogalaxy.
Warm dark matter: similar than a protogalaxy.
Hot dark matter: bigger than a protogalaxy.
Protogalaxy in in physical cosmology is a cloud of gas which form
a galaxy.
7. DARK MATTER
Alternative theories
Numerous alternatives have been proposed to explain these
observations without the need for a large amount of undetected
matter. Most of these modify the laws of gravity established by
Newton and Einstein in some way.
