Constraining Dark Energy through the Stability of Cosmic Structures
  For a general dark-energy equation of state, we estimate the maximum possible
radius of massive structures that are not destabilized by the acceleration of
the cosmological expansion. A comparison with known stable structures
constrains the equation of state. The robustness of the constraint can be
enhanced through the accumulation of additional astrophysical data and a better
understanding of the dynamics of bound cosmic structures.
