Abstract
We calculate particle production during inflation and in the early stages of reheating after inflation in models with a charged scalar field coupled to Abelian and non-Abelian gauge fields. A detailed analysis of the power spectra of primordial electric fields, magnetic fields and charge fluctuations at the end of inflation and preheating is provided. We carefully account for the Gauss constraints during inflation and preheating, and clarify the role of the longitudinal components of the electric field. We calculate the timescale for the back-reaction of the produced gauge fields on the inflaton condensate, marking the onset of non-linear evolution of the fields. We provide a prescription for initial conditions for lattice simulations necessary to capture the subsequent nonlinear dynamics. On the observational side, we find that the primordial magnetic fields generated are too small to explain the origin of magnetic fields on galactic scales and the charge fluctuations are well within observational bounds for the models considered in this paper.
Highlights
Assuming the scalar field plays the role of the inflaton and treating the gauge fields as perturbations, the evolution of ρ(τ ) can be determined from eq (2.17): ∂τ2 ρ 2H∂τ ρ a2 (2.22)where H is given by the 00 background Einstein equation H2a2 3m2pl (∂τ ρ)2 2a2 (2.23)The electric and magnetic fields vanish at the background level.2.3.2 Linearized perturbations in position spaceFrom eq (2.17) and eq (2.18) we get the equations of motion for diffeomorphism and U(1) gauge invariant scalar perturbations:
We argue for the use of well defined Coulumb gauge variables for analysing non-perturbative particle production during preheating at the end of inflation
This is because the vacuum fluctuations in GLk can be enhanced due to horizon crossing during inflation or non-adiabatic particle production during preheating
Summary
Where R is the Ricci scalar, g is the determinant of the metric and mPl is the reduced Planck mass. The matter action contains a complex scalar field φ and the gauge field Aμ: Sm =. The action Sm is invariant under local U(1) gauge transformations φ. The total action is invariant under space-time differomorphisms. The gauge symmetry implies that not all of the components of the 4-vector Aμ and the real and imaginary parts of the scalar field are physical degrees of freedom (dof). We remedy this redundancy by working in the appropriate set of gauge invariant variables or by fixing the gauge. It is convenient to work in local U(1) gauge invariant variables given by the following five fields: ρ(xν) and Gμ(xν) ≡ Aμ(xν) + ∇μΩ(xν).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
