Chasing Lambda

Understand

Recent astronomical observations of SNIa, CMB, as well as BAO in the Sloan Digital Sky Survey, suggest that the current Universe has entered a stage of an accelerated expansion with the transition redshift at $z \simeq 0.5$.

• While the simplest candidates to explain this fact is cosmological constant/vacuum energy, there exists a serious problem of coincidence.
• In theoretical cosmology we can find many possible approaches alleviating this problem by applying new physics or other conception of dark energy.
• We consider state of art candidates for the description of accelerating Universe in the framework of the Bayesian model selection.