The Matter Bounce Scenario in Loop Quantum Cosmology

Understand

In the matter bounce scenario, a dust-dominated contracting space-time generates scale-invariant perturbations that, assuming a nonsingular bouncing cosmology, propagate to the expanding branch and set appropriate initial conditions for the radiation-dominated era.

• Since this scenario depends on the presence of a bounce, it seems appropriate to consider it in the context of loop quantum cosmology where a bouncing universe naturally arises.
• For a pressureless collapsing universe in loop quantum cosmology, the predicted power spectrum of the scalar perturbations after the bounce is scale-invariant and the tensor to scalar ratio is negligibly small.
• A slight red tilt can be given to the scale-invariance of the scalar perturbations by a scalar field whose equation of state is $P = - \epsilon \rho$, where $\epsilon$ is a small positive number.