“School of Astronomy”
Back to Papers HomeBack to Papers of School of Astronomy
Paper IPM / Astronomy / 14276  


Abstract:  
The celebrated Weinberg theorem in cosmological perturbat
ion theory states that there always exist two adiabatic scalar modes in which the comoving curvature perturbation is conserved on superhorizon scales. In particular when the perturbations are generated from a single source, such as in single field models of inflation, both of the two allowed independent solutions are adiabatic and conserved on superhorizon scales.There are few known examples in literature which violate this theorem. We revisit the theorem and specify the loopholes in some technical assumptions which violate the theorem in models of nonattractor inflation, fluid inflation, solid inflation and in the model
of pseudo conformal universe
Download TeX format 

back to top 