On the visible size and geometry of aggressively expanding civilizations
  at cosmological distances
  If a subset of advanced civilizations in the universe choose to rapidly
expand into unoccupied space, these civilizations would have the opportunity to
grow to a cosmological scale over the course of billions of years. If such life
also makes observable changes to the galaxies they inhabit, then it is possible
that vast domains of life-saturated galaxies could be visible from the Earth.
Here, we describe the shape and angular size of these domains as viewed from
the Earth, and calculate median visible sizes for a variety of scenarios. We
also calculate the total fraction of the sky that should be covered by at least
one domain. In each of the 27 scenarios we examine, the median angular size of
the nearest domain is within an order of magnitude of a percent of the whole
celestial sphere. Observing such a domain would likely require an analysis of
galaxies on the order of a Gly from the Earth.
