Abstract Details

Name: Debottam Nandi
Affiliation: IISER Thiruvananthapuram
Conference ID: ASI2016_898
Title : Complete Hamiltonian analysis of cosmological perturbations at all orders.
Authors and Co-Authors : Dr. S. Shankaranarayanan, IISER Thiruvananthapuram
Abstract Type : Poster
Abstract Category : General Relativity and Cosmology
Abstract : Cosmological perturbation theory is currently a preferred mathematical procedure to compare the equations of gravity with precise observations. However, due to the difficulties in interpreting gauge-invariance and invertibility in Hamiltonian formalism, there is no consistent and generalized Hamiltonian analysis for cosmological perturbation theory at any order for any kind of model of gravity. In this work, using a simple model, we provide a simple mathematical approach to deal with all the difficulties to obtain a consistent Hamiltonian formalism and extend the approach to canonical scalar field. We show that our approach can be applied to any order of perturbation for any first order derivative fields. We also apply our approach to Galilean scalar field model and show that, there is no extra degrees of freedom, as expected, at every order of perturbation and obtain all consistent equations of motion. We compare and contrast our approach to the Lagrangian approach (Chen et al [2006]) for extracting higher order correlations and show that our approach is quick and robust and can be applied to any model of gravity and matter fields without invoking slow-roll approximation.