Cosmology and Large Scale Structure
In the last two decades, cosmology, the study of the Universe as a whole, has experienced dramatic progress. Several independent observations have resulted in a remarkably accurate determination of the Big Bang model, complemented with an initial period of inflation, that describes the evolution of our Universe over the past 13.8 billion years with only a handful of parameters. We can now undoubtedly say that cosmology has entered a new age of precision. [+]
The observational effort that brought about precision cosmology has not slowed down and the interpretation of these observations is as active as ever. Several observables are being considered: the anisotropy of the Cosmic Microwave Background radiation (CMB), a fossil coming from the early universe when its age was only 380,000 years old, which was produced when matter formed atoms for the first time and the radiation decoupled (or in other words, was able to freely propagate in a transparent universe); the use of supernovae as standard candles to probe the Hubble law, and through it the geometry of the universe at large redshifts; gravitational lensing caused by massive structures intersecting the light beams emitted by distant objects; and the clustering of baryons on all scales. Two outstanding results emerging from these observations are that the universe is in a state of accelerated expansion, and that 84% of all the matter is of an unknown type, called dark matter, that so far has not been found to interact with the known, ordinary (baryonic) matter in any way other than gravity. In addition, we know there is a small but non-negligible contribution to the mass density of the Universe from neutrinos, acting as radiation and hot dark matter. The dark matter and the acceleration of the expansion are among the most striking scientific findings of the century, with foreseeable consequences for fundamental physics, and their origin is being researched from different perspectives.
ICCUB Contribution
One of the main interests at ICCUB is the study of the connection between cosmological observations and the physics behind the standard cosmological model, hoping to shed some light on the “open questions” in cosmology. Cosmology is tackled at the ICCUB through both an observational and a theoretical approach. [+]
The research directions range from the inflationary model, the effects of massive neutrinos in cosmology, the Cosmic Microwave Background (CMB) and the epoch of reionization, to the formation and evolution of galaxies and the distribution of gas in space, including statistical applications and data analysis. Research is also being carried out into the nature of dark matter and the primordial fluctuations that gave rise to galaxies and larger structures in the universe. The observational tools available for these studies are gravitational lensing by galaxies, clusters of galaxies and large-scale structure, microlensing of stars or quasars by any kind of compact object, the spatial distribution of galaxies and of matter in intergalactic space that is measured from absorption signatures in spectra of background sources, and the structure of dark matter halos studied through the dynamics of galaxies in clusters.
The ICCUB is also involved in several cosmological projects of ground-based and space surveys, such as DESI, the EUCLID science working group, the CORE science working, EMU, the JPAS and JPLUS photometric surveys in the Javalambre Observatory, and the WEAVE spectroscopic survey in WHT. See the projects section for more information.
Lines of Research
- Large scale structure of galaxies and the intergalactic medium.
- Galaxy redshift survey.
- Microwave background radiation anisotropies.
- Baryonic acoustic oscillations.
- Dark matter and dark energy.
- Neutrinos in cosmology.
- Dark matter, black holes and cosmology with gravity waves.
- Lyman-alpha emission from galaxies at high redshifts.
- Reionization of the intergalactic medium.
- Gravitational lensing as a dark matter probe.
Members
