Falsifying Cosmological Constant
  One of the main goals of physical cosmology is to reconstruct the expansion
history of the universe and finding the actual model of dark energy. In this
article I review the difficulties of understanding dark energy and discuss
about two strategic approaches, 'reconstructing dark energy' and 'falsifying
dark energy models'. While one can use the data to reconstruct the expansion
history of the universe and the properties of dark energy using novel
approaches, considering the data limitations and its uncertainties we have to
deal with cosmographic degeneracies that makes it difficult to distinguish
between different dark energy models. On the other hand one can use the power
of the data to falsify an assumed model using advanced statistical techniques.
Within all these issues, focusing on falsification of cosmological constant has
a particular importance since finding any significant deviation from $\Lambda$
would result to a break through in theoretical physics, ruling out the standard
concordance model of cosmology.
