Einstein's Universe: Cosmological structure formation in numerical relativity
Abstract
We perform largescale cosmological simulations that solve Einstein's equations directly via numerical relativity. Starting with initial conditions sampled from the cosmic microwave background, we track the emergence of a cosmic web without the need for a background cosmology. We measure the backreaction of largescale structure on the evolution of averaged quantities in a matterdominated universe. Although our results are preliminary, we find the global backreaction energy density is of order 10^{8} compared to the energy density of matter in our simulations, and is thus unlikely to explain accelerating expansion under our assumptions. Sampling scales above the homogeneity scale of the Universe (100  180 h^{1} Mpc ), in our chosen gauge, we find 23% variations in local spatial curvature.
 Publication:

Physical Review D
 Pub Date:
 March 2019
 DOI:
 10.1103/PhysRevD.99.063522
 arXiv:
 arXiv:1807.01711
 Bibcode:
 2019PhRvD..99f3522M
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 19 pages, 16 figures, accepted for publication in Phys. Rev. D