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Title: Connection between Newtonian simulations and general relativity

Journal Article · · Physical Review. D, Particles Fields
 [1];  [2]
  1. Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, New Jersey 08544 (United States)
  2. School of Natural Sciences, Institute for Advanced Study, Olden Lane, Princeton, New Jersey 08540 (United States)

On large scales, comparable to the horizon, the observable clustering properties of galaxies are affected by various general relativistic effects. To calculate these effects one needs to consistently solve for the metric, densities, and velocities in a specific coordinate system or gauge. The method of choice for simulating large-scale structure is numerical N-body simulations which are performed in the Newtonian limit. Even though one might worry that the use of the Newtonian approximation would make it impossible to use these simulations to compute properties on very large scales, we show that the simulations are still solving the dynamics correctly even for long modes and we give formulas to obtain the position of particles in the conformal Newtonian gauge given the positions computed in the simulation. We also give formulas to convert from the output coordinates of N-body simulations to the observable coordinates of the particles.

OSTI ID:
21502715
Journal Information:
Physical Review. D, Particles Fields, Vol. 83, Issue 12; Other Information: DOI: 10.1103/PhysRevD.83.123505; (c) 2011 American Institute of Physics; ISSN 0556-2821
Country of Publication:
United States
Language:
English