A new framework for numerical simulations of structure formation

Understand

The diversity of structures in the Universe (from the smallest galaxies to the largest superclusters) has formed under the pull of gravity from the tiny primordial perturbations that we see imprinted in the cosmic microwave background.

• A quantitative description of this process would require description of motion of zillions of dark matter particles.
• This impossible task is usually circumvented by coarse-graining the problem: one either considers a Newtonian dynamics of "particles" with macroscopically large masses or approximates the dark matter distribution with a continuous density field.
• There is no closed system of equations for the evolution of the matter density field alone and instead it should still be discretized at each timestep.