The Universe in a Soap Film
  The value of the cosmological constant is one of the major puzzles of modern
cosmology: it is tiny but nonzero. Sorkin predicted, from the Causet approach
to quantum gravity, that the cosmological constant has quantum fluctuations.
The predicted order of magnitude of the fluctuations agrees with the
subsequently observed value of the cosmological constant. We had earlier
developed an analogy between the cosmological constant of the Universe and the
surface tension of fluid membranes. Here we demonstrate by computer simulations
that the surface tension of a fluid membrane has statistical fluctuations
stemming from its discrete molecular structure. Our analogy enables us to view
these numerical experiments as probing a small and fluctuating cosmological
constant. Deriving insights from our analogy, we show that a fluctuating
cosmological constant is a GENERIC feature of quantum gravity models and is far
more general than the specific context in which it was originally proposed. We
pursue and refine the idea of a fluctuating cosmological constant and work
towards making further testable predictions.
