Nagoya University: Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI)

Nagoya University

Japanese


QG-KMI Joint Seminar
"Future cosmological singularities: theory and observations"
Diego Sáez Gomez
(Institute of Space Studies of Catalonia (IEEC))
September 27, 2016 (Tue) 15:00-
KMI Science Symposia (ES635)
Abstract:

General Relativity contains inherently singularities, which refer to geodesically incomplete spacetimes, according to the usual definitions by Hawking and Ellis. Over the last years, what is called in the literature by "future cosmological singularities" have drawn much attention within the scientific community. In this talk, I will review and show the physical features of these singularities, and I will also show that every future singularity may be the consequence of a single one: the so-called Q-singularity. In addition, I will present several phenomenological parameterizations of the Hubble expansion rate to model different singularities existing in the literature and use SN Ia, BAO and H(z) data to constrain how far in the future the singularity needs to be, and how good the parametrizations are in comparison with the concordance model in cosmology.