1210.6650
Dark energy simulations
Baldi
Discuss range of scenarios for the cosmic acceleration that have been successfully investigated by means of dedicated N-body simulations, with broad summary of the main results. Focus on few selected studies that have lead to significant advancements; provide a comprehensive list of references for a larger number of related works. Mainly focus on outcomes of various simulations studies.
1210.6651
Retarded Green's function of a Vainshtein system and Galileon waves
Chu, Trodden
Galileon: in extra-dimensional modified gravity models (e.g., DGP theory), the scalar field (that can be interpreted as describing the bending of the brane in the extra dimension) in the decoupling limit (a constant strength of self-interaction of the scalar field, while gravitational interaction strength is taken to infinity) obeys the galilean symmetry---hence they are called Galileons. It is a new 4-d scalar field theory that has nice properties: only 5 terms in the scalar field; equations of motion are only second order in time; a range of energy scales over which the Galileon terms are important---quantum mechanical effects irrelevant; Galileon terms are unrenormalized (no quantum corrections from other Galileon terms).
1210.6652
A new approach to simulating collisionless dark matter fluids
Hahn, Abel, Kaehler
Tetrahedral tesselation of 6-d phase space, using piecewise linear approximation of phase space distribution function, rather than particle discretisation. Modify by using pseudo-particles that approximate the masses of tetrahedral cells up to quadrupolar order as the location for cloud-in-cell (CIC) deposit instead of the particles locations themselves (i.e., standard CIC deposit). Give improved stability and more accurate dynamics of collisionless DM fluid at high force and low mass resolution.
1210.6694
The DEEP2 galaxy redshift survey: clustering dependence on galaxy stellar mass and star formation rate at z~1
Mostek, Coil, Cooper, Davis, Newman, Weiner
Strong positive correlation between M* and clustering amplitude (at z~1) on 1-10 Mpc/h scales for blue, SF galaxies with 9.5< log(M*/Msun) < 11 and no dependence for red, quiescent galaxies with 10.5 < log(M*/Msun) < 11.5. Cluster amplitude increases strongly with increasing SFR and decreasing sSFR. For red galaxies, there is no significant correlation between clustering amplitude either SFR or sSFR. Blue galaxies with high SFR or low sSFR are as clustered on large scales as red galaxies. Find that the clustering trend observed with SFR can be explained mostly, but not entirely, by the correlation between stellar mass and clustering amplitude for blue galaxies. These results not consistent with the high sSFR population being dominated by major mergers. Measure clustering amplitude on small scales (<0.3 Mpc/h) and find an enhanced clustering signal relative to the best-fit large-scale power law for red galaxies with high stellar mass, blue galaxies with high SFR, and both red and blue galaxies with high sSFR. The increased small-scale clustering for galaxies with high sSFRs is likely linked to triggered SF in interacting galaxies. These measurements provide strong constraints on galaxy evolution and halo occupation distribution models at z~1.
1210.6706
Quantifying properties of ICM inhomogeneities
Zhuravleva et al
Distribution of gas properties in a given radial shell can be well described by a log-normal PSF and tail: former corresponding to a nearly hydrostatic bulk component (~99% of the volume), while the tail corresponds to high density inhomogeneities; separation of diffuse and clumpy components of ICM. Inhomogeneity exists even in relaxed clusters.
No comments:
Post a Comment