PAU Consolider: A new observational approach to measure dark energy with baryon acoustic oscillations

por Narciso Benitez (IAA, Granada)

viernes 15 jun. 2007 11:00 → 12:00 Europe/Madrid

Sala Reuniones Sotano (Edf. Institutos de Investigación)

The origin of the so-called ``dark energy" is often considered the most important scientific problem of our time, and it presents a fundamental challenge for particle physics, astrophysics and cosmology. I briefly review and describe the most promising observational approaches which are being currently developed to tackle this problem. In particular, baryon acoustic oscillations (BAO) have recently emerged as one of the most powerful techniques to characterize the equation of state of dark energy and its possible evolution. In the next years, several large scale projects will attempt to use BAO to characterize dark energy by measuring redshifts for hundreds of thousands of galaxies. We present a new approach to extract information on dark energy from BAO, based on the comparison of the observed colors of galaxies finely sampled at many wavelenghts, with those of a redshifted spectral template("photometric" redshifts) . This method turns out to be much more efficient than conventional spectroscopic observations, and it also provides extremely useful data for other astrophysical applications. I describe the main characteristics of a survey based on this approach and proposed by the PAU collaboration.