Separate universe simulations

A Separate Universe Approach to Quintessence Perturbations

There is some observational evidence that the dark energy may not be smooth on large scales. This makes it worth while to try and get as simple and as intuitive a picture of how dark energy perturbations behave so as to be able to better constrain possible models of dark energy and the generation of large scale perturbations. The separate Universe method provides an easy way to evaluate cosmolo...

Simulations in Early Universe Theory

We give an impression of the type of results that have been obtained with numerical lattice simulations of field theory in the early universe. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. LG? EW QCD NS EQ DEC BG? end of inflation now ? ? Figure 1: Transitions in the early universe. Going backwards in time there was the ...

Simulations of Structure Formation in the Universe

Cosmic structure has formed as a result of gravitational amplification of primordial density fluctuations together with the action of other physical processes (adiabatic gas dynamics, radiative cooling, photoionization and recombination, radiative transfer). These complex nonlinear processes, acting over a wide range of length scales (from kiloparsecs to tens of megaparsecs), make this a diffic...

Universe: Simulations of Structure and Galaxy Formation

Chemodynamical Simulations of Galaxies and the Universe

We simulate the formation and evolution of galaxies with a hydrodynamical model including star fromation, supernova feedback, and chemical enrichment. From the comparison with observed elemental abundances, we study the evolution of galaxies and the origin of heavy elements (Galactic Archaeology). A large fraction of hypernovae is required from the observed abundance ratios in the Milky Way Gal...