1207.3621 (Jaume de Haro)

Does loop quantum cosmology replace the big rip singularity by a
non-singular bounce?    [PDF]

Jaume de Haro

It is stated that holonomy corrections in loop quantum cosmology introduce a modification in Friedmann's equation which prevent the big rip singularity. However in \cite{h12} it has been proved that this modified Friedmann equation is obtained in an inconsistent way, what means that the results deduced from it, in particular the big rip avoidance, are not justified. The problem is that holonomy corrections modify the gravitational part of the Hamiltonian of the system leading, after Legendre's transformation, to a non covariant Lagrangian which is in contradiction with one of the main principles of General Relativity. A more consistent way to deal with the big rip singularity avoidance is to disregard modification in the gravitational part of the Hamiltonian, and only consider inverse volume effects \cite{bo02a}. In this case we will see that, not like the big bang singularity, the big rip singularity survives in loop quantum cosmology.

View original: http://arxiv.org/abs/1207.3621