Cosmology at CIEMAT

The progress that cosmology has undergone in the last 20 years represents a revolution in our understanding of the origin and evolution of the Universe. Moreover, showing how close cosmology and particle physics are, it has revealed that we need to go beyond the standard model at least three times if we want to describe the universe. In particular, the discovery of the accelerated expansion of the Universe in 1998 means a first range scientific challenge. The mechanism that causes the accelerated expansion, generally called dark energy, has no explanation within the standard model of particle physics, even if it makes up 70% of the matter-energy content of the Universe. But even more, the next most abundant component, the dark matter, that makes up 25%  of the Universe content, again can not be fitted in the standard model. Whatever its fundamental components are, they lie beyond the current thaory of matter. Last but nit least, the physical processes of the very early Universe, like baryogenesis and, most probably, the cosmic inflation, require also new physics beyond the standar model.

Understanding the microscopic physics of the dark side of the Universe is one of the main challenges that physics faces in XXi century. The CIEMAT Cosmology Group has as its goal to contribute to the understanding of these mysteries, that lie in the frontier between cosmolgy and particle physics. Therefore, we particpate in several projects that are specially designed to progress in the understanding of these phenomena. The Dark Energy Survey (DES), the Physics of the Acceleration Universe Survey (PAU) and the Dark Energy Spectroscopic Instrument (DESI). All of them are large international projects with the goal of building huge sky maps, locating and measuring the properties of millions of galaxies, and from these properties, extract the physics of dark matter and dark energy. Each one of these maps has different features, that make them sensitive to different aspects of the dark sector of the Universe. The combination of all of them is going to bring a substantial improvement in our understanding of the dark side of the Universe.