Cosmic velocity fields and their interpretation

Observational biases in Lagrangian reconstructions of cosmic velocity fields

Lagrangian reconstruction of large-scale peculiar velocity fields can be strongly affected by observational biases. We develop a thorough analysis of these systematic effects by relying on specially selected mock catalogues. For the purpose of this paper, we use the Monge-Ampère-Kantorovitch (MAK) reconstruction method, although any other Lagrangian reconstruction method should be sensitive to ...

Gaussianity of Cosmic Velocity Fields and Linearity of the Velocity – Gravity Relation

We present a numerical study of the relation between the cosmic peculiar velocity field and the gravitational acceleration field. We show that on mildly non-linear scales (4–10 hMpc Gaussian smoothing), the distribution of the Cartesian coordinates of each of these fields is well approximated by a Gaussian. In particular, their kurtoses and negentropies are small compared to those of the veloci...

Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation

We discuss the influence of large scale cosmic magnetic fields on the propagation of hadronic cosmic rays above 10 eV based on large scale structure simulations. Our simulations suggest that rather substantial deflection up to several tens of degrees at 10 eV are possible for nucleon primaries. Further, spectra and composition of cosmic rays from individual sources can depend on magnetic fields...

Variance of the Higher - Order Cumulants of Cosmic Density and Velocity Fields

If primordial fluctuation is Gaussian distributed, higher-order cumulants of the cosmic fields reflect nonlinear mode coupling and provide useful information of gravitational instability picture of structure formation. We show that their expected deviation (sample variance) from the universal values is nonvanishing even in linear theory in the case where observed volume is finite. As a result, ...

Cosmic Magnetic Fields