857 citations · 4.9k across the 68 of their papers we have counts for
4 papers · 1 filter
Quantifying the behaviour of curvature perturbations during inflation
Ellie Nalson, Adam J. Christopherson, Ian Huston +1
How much does the curvature perturbation change after it leaves the horizon, and when should one evaluate the power spectrum? To answer these questions we study single field inflat…
The magnitude of the non-adiabatic pressure in the cosmic fluid
Iain A. Brown, Adam J. Christopherson, Karim A. Malik
Understanding the non-adiabatic pressure, or relative entropy, perturbation is crucial for studies of early-universe vorticity and Cosmic Microwave Background observations. We calc…
Second Order Perturbations During Inflation Beyond Slow-roll
Ian Huston, Karim A. Malik
We numerically calculate the evolution of second order cosmological perturbations for an inflationary scalar field without resorting to the slow-roll approximation or assuming larg…
Comparing different formulations of non-linear cosmological perturbation theory
Adam J. Christopherson, Karim A. Malik, David R. Matravers +1
We compare and contrast two different metric based formulations of non- linear cosmological perturbation theory: the MW2009 approach in [K. A. Malik and D. Wands, Phys. Rept. 475 (…