Effects of variable Newton constant during inflation

作者：Abolhasani Ali Akbar^*; Firouzjahi Hassan; Noorbala Mahdiyar

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2012, 86(4): 043522.

DOI：10.1103/PhysRevD.86.043522

In this paper the effects of a time-dependent Newton constant G during inflation are studied. We present the formalism of curvature perturbations in an inflationary system with a time-dependent Newton constant. As an example we consider a toy model in which G undergoes a sudden change during inflation. By imposing the appropriate matching conditions the imprints of this sharp change in G on the curvature perturbation power spectrum are studied. We show that if G increases (decreases) during the transition the amplitude of curvature perturbations on large scales decreases (increases). In our model with a sudden change in G continuous sinusoidal modulations on the curvature power spectrum is induced. However, in a realistic scenario in which the change in G has some finite time scale we expect these sinusoidal modulations to be damped on short scales. The generated features may be used to explain the observed glitches on the CMB power spectrum. This puts a bound on Delta G during inflation of roughly the same order as current bounds on Delta G during the entire observed age of the universe.

• 出版日期2012-8-17