Cosmological perturbations in FRW model with scalar field within Hamilton-Jacobi formalism and symplectic projector method

TL;DR

This paper applies Hamilton-Jacobi and symplectic projector methods to analyze scalar perturbations in FRW cosmology, identifying physical degrees of freedom and gauge conditions.

Contribution

It introduces a novel combination of Hamilton-Jacobi analysis and symplectic projector techniques for cosmological perturbations.

Findings

Identification of gauge conditions from consistency requirements

Extraction of physical degrees of freedom using symplectic projector

Discussion on the role of Hamiltonians and gauge variables

Abstract

The Hamilton-Jacobi analysis is applied to the dynamics of the scalar fluctuations about the Friedmann-Robertson-Walker (FRW). The gauge conditions are found from the consistency conditions. The physical degrees of freedom of the model are obtain by symplectic projector method. The role of the linearly dependent Hamiltonians and the gauge variables in Hamilton-Jacobi formalism is discussed.