Mar 13 (Wed), 14:15 in A315   

Mikko Lavinto (Helsinki)


Backreaction in Swiss Cheese Models

One popular approach to constructing inhomogeneous models has been so called Swiss Cheese models, where spherically symmetric inhomogeneous patches are embedded into a background FRW universe. I will present a set of conditions that force the average expansion rate of the inhomogeneities to be close to that of the background universe in these models. In addition, I will construct a toy model where one of these conditions is violated. I will use this model to compare the effect of volume-averaging on cosmological observables, like redshift and luminosity distance, and explain why there may be differences.