The Evolution of Our Local Cosmic Domain: Effective Causal Limits

Understand

The causal limit usually considered in cosmology is the particle horizon, delimiting the possibilities of causal connection in the expanding universe.

• However it is not a realistic indicator of the effective local limits of important interactions in spacetime.
• We consider here the matter horizon for the Solar System, that is,the comoving region which has contributed matter to our local physical environment.
• This lies inside the effective domain of dependence, which (assuming the universe is dominated by dark matter along with baryonic matter and vacuum-energy-like dark energy) consists of those regions that have had a significant active physical influence on this environment through effects such as matter accretion and acoustic waves.