Some remarks on new numerical estimations of the Rees-Sciama effect

Abstract

In previous editions of Frontiers of Fundamental Physics Symposia, [1,2,3,4,5] we presented numerical computations of Cosmic Microwave Background (CMB) anisotropies at small angular scales (high 's). Our ray-tracing procedure was implemented in different N-body codes to calculate these anisotropies. A certain Particle-Mesh (PM) code and parallel Adaptative-ParticleParticle-Particle-Mesh (AP3M) Hydra codes have been used. This way we have been able to estimate weak lensing, Rees-Sciama (RS) and Sunyaev-Zel'dovich contributions to the CMB anisotropy. The use of a parallel AP3M code led to more accurate computations [6,7], but further research is necessary. Almost a decade ago, we computed the RS effect by using a PM N-body code [8]. Here, some preliminary estimations of the RS effect, obtained with a parallel AP3M Hydra code, are presented. These results improve on those obtained with PM codes and, moreover, they are the starting point for a more detailed study of the RS anisotropy component.