Apparent Acceleration and an Alternative Concordance from Causal
  Backreaction
  A phenomenological formalism is presented in which the apparent acceleration
of the universe is generated by cosmic structure formation, without resort to
Dark Energy, modifications to gravity, or a local void. The observed
acceleration results from the combined effect of innumerable local
perturbations due to individually virializing systems, overlapping together in
a smoothly-inhomogeneous adjustment of the FRW metric, in a process governed by
the causal flow of inhomogeneity information outward from each clumped system.
After noting how common arguments claiming to limit backreaction are physically
unrealistic, models are presented which fit the supernova luminosity distance
data essentially as well as $\Lambda$CDM, while bringing several important
cosmological parameters to a new Concordance. These goals are all achieved with
a second-generation version of our formalism that accounts for the negative
feedback of Causal Backreaction upon itself due to the slowed propagation of
gravitational inhomogeneity information.
