In this paper we prove a number of exact relations between optical observables, such as
trigonometric parallax, position drift, and the proper motion of a luminous source, in addition …

In this work we present the first results from a new ray-tracing tool to calculate cosmological
distances in the context of fully nonlinear general relativity. We use this tool to study the …

Real-time measurements are becoming feasible in cosmology, where the next generation of
telescopes will detect the temporal change of redshifts and sky positions of individual …

We consider the form of Hubble diagrams that would be constructed by observers in
universes that are homogeneous but anisotropic, when averaged over suitably large length …

We consider the form of Hubble diagrams that would be constructed by observers in
universes that are homogeneous but anisotropic, when averaged over suitably large …