- Este evento ha pasado.
noviembre 26, 2018 @ 3:00 pm - 5:00 pm
Lugar: Seminario de Física Teórica, planta 2
Día: Lunes 26 de noviembre
Ponente: Rubén Arjona Fernández
Título: Unraveling the effective fluid approach for f(R) models in the sub-horizon approximation.
Abstract: We provide explicit formulae for the effective fluid approach of f(R) theories, such as the Hu & Sawicki and the designer models. Using the latter and simple modifications to the CLASS code, which we call EFCLASS, in conjunction to very accurate analytic approximations for the background evolution, we obtain competitive results in a much simpler and less error-prone approach. We also
derive the initial conditions in matter domination and we find they differ from those already found in the literature for a constant w model. We then use the aforementioned models to derive constraints from the latest cosmological data, including supernovae, BAO, CMB, H(z) and growth-rate data, and we find they are statistically consistent to the LCDM model. Finally, we find that the viscosity parameter in realistic models is not constant as commonly assumed, but
rather evolves significantly over several orders of magnitude, something which could affect forecasts of upcoming surveys.
Muchas gracias y un saludo