Speaker
Tiago Gonçalves (online)
(Instituto de Astronomia e Astrofísica e Ciências do Espaço)
Description
Might the universe, one day, undergo a Big Crunch, Big Freeze, Big Rip, or some other singularity? A "sudden singularity" occurs if the energy density, the scale factor and the Hubble function remain finite while there is a divergence in higher derivatives of the scale factor which could be accompanied by a pressure divergence. We investigate whether sudden singularities could arise in the f(R,T) theory of modified gravity. We find that the conservation of matter can prevent sudden singularities in this theory. However, due to matter-geometry couplings, f(R,T) gravity does not require matter conservation. Thus, we investigate a particular model where there is a sudden singularity in the third time derivative of the scale factor.
