146 citations · 247 across the 4 of their papers we have counts for
14 papers
Numerical Relativity as a New Tool for Fundamental Cosmology
Anna Ijjas
Advances in our understanding of the origin, evolution and structure of the universe have long been driven by cosmological perturbation theory, model building and effective field t…
The Effects of Multiple Modes and Reduced Symmetry on the Rapidity and Robustness of Slow Contraction
Anna Ijjas, Frans Pretorius, Paul J. Steinhardt +1
We demonstrate that the rapidity and robustness of slow contraction in homogenizing and flattening the universe found in simulations in which the initial conditions were restricted…
Ultralocality and Slow Contraction
Anna Ijjas, Andrew P. Sullivan, Frans Pretorius +2
We study the detailed process by which slow contraction smooths and flattens the universe using an improved numerical relativity code that accepts initial conditions with non-pertu…
Nearly scale-invariant curvature modes from entropy perturbations during graceful exit
Anna Ijjas, Roman Kolevatov
In this Letter, we describe how a spectrum of entropic perturbations generated during a period of slow contraction can source a nearly scale-invariant spectrum of curvature perturb…
Sourcing curvature modes with entropy perturbations in non-singular bouncing cosmologies
Anna Ijjas, Roman Kolevatov
The observed temperature fluctuations in the cosmic microwave background can be traced back to primordial curvature modes that are sourced by adiabatic and/or entropic matter pertu…
Robustness of slow contraction to cosmic initial conditions
Anna Ijjas, William G. Cook, Frans Pretorius +2
We present numerical relativity simulations of cosmological scenarios in which the universe is smoothed and flattened by undergoing a phase of slow contraction and test their sensi…