From inflation to late time acceleration with a decaying vacuum coupled to radiation or matter

Stéphane Fay
2014 Physical Review D  
We consider General Relativity with matter and radiation, one of these fluids being coupled to vacuum. We find that Universe dynamics starts by an inflation phase if the coupled fluid has a negative energy density at early time. Then, there is always a finite scale factor singularity but when vacuum and matter are coupled and matter density behaves like a negative radiation density. Moreover, the convergence to the LCDM model is clearly easier to reach when vacuum is coupled to matter rather
more » ... n to radiation. Two classes of theories are studied to illustrate these results.
doi:10.1103/physrevd.89.063514 fatcat:uzxcmwhxwjcrvd5sckltspsjxm