One of the larger puzzles (coincidences) of cosmology is that the cosmological constant $\Lambda$ has roughly (within a factor of order one) the value determined by the (inverse square) radius of the present observable universe (about 3.3 times the Hubble radius).

At the same time, cosmological data states that dark energy obeys $w=-1$ with a high precision of only a few percent. This is usually interpreted as meaning that dark energy / the cosmological constant is really *constant* in time.

Could it be that $\Lambda$ decays with time (and therefore would *always* be given by the inverse square radius of the observable universe (or the Hubble radius, with the same factor of order one), thus avoiding the coincidence issue) and that $w=-1$ holds nevertheless?