¡¡Coloquio!!

Miércoles 30 a las 12:00 en CU y a las 10:00h en Ensenada por videoconferencia:

Krzystoff Bolejko
(Centro Astronomico Nicolas Copernico, Academia de Ciencias de Polonia)

Inhomogeneous cosmological models
as alternatives to dark energy

The Universe, as observed, is very inhomogeneous on almost all scales. However, in a standard approach to cosmology, it is assumed that the Universe can be described by the homogeneous and isotropic Friedmann models. The Friedmann models provide a remarkably precise description of cosmological observations, but to achieve this we need to pay a price -in order to obtain concordance with observations it must be assumed that the Universe is filled with an unknown substance called dark energy. However, this substance has never been observed directly and,since it has very unusual properties, some have begun to ask whether dark energy is real or if it is the description of the Universe which, requires the existence of such an exotic entity, that is invalid.
During my talk I will present inhomogeneous cosmological models and discuss how they can be use to fit cosmological observations without the need for dark energy.