The aim of this set of lectures is a systematic presentation of a 1+ 3 covariant approach to
studying the geometry, dynamics, and observational properties of relativistic cosmological …

It has been known for a long time that the gauge problem plagues the study of density
perturbations in cosmology. The quantity δμ/μ (the fractional variation in density along a …

The effective evolution of an inhomogeneous universe model in any theory of gravitation
may be described in terms of spatially averaged variables. In Einstein's theory, restricting …

No. In a number of papers, Green and Wald argue that the standard FLRW model
approximates our Universe extremely well on all scales, except close to strong-field …

Cosmic acceleration is explained quantitatively, purely in general relativity with matter
obeying the strong energy condition, as an apparent effect due to quasilocal gravitational …

We outline the key steps toward the construction of a physical, fully relativistic cosmology.
The influence of inhomogeneities on the effective evolution history of the Universe is …

We analyze a toy Swiss-cheese cosmological model to study the averaging problem. In our
Swiss-cheese model, the cheese is a spatially flat, matter only, Friedmann-Robertson …

Averaged inhomogeneous cosmologies lie at the forefront of interest, since cosmological
parameters such as the rate of expansion or the mass density are to be considered as …

In the context of the averaging problem in relativistic cosmology, we provide a key to the
interpretation of cosmological parameters by taking into account the actual inhomogeneous …

Since its decovery during the late 90's, the dimming of distant SN Ia apparent luminosity has
been mostly ascribed to the influence of a mysterious dark energy component. Formulated in …