on behalf of the Archeops Collaboration includes scientists from Caltech (USA), Cardiff Univ., CESR (Toulouse), CSNSM (Orsay), CRTBT (Grenoble), IAS (Orsay), IAP (Paris), IROE (Firenze, Italy), ISN (Grenoble), JPL (USA), LAL (Orsay), LAOG (Grenoble), Landau Institute (Russia), La Sapienza Univ. (Roma, Italy), LAOMP (Toulouse), Maynooth Univ. (Ireland), Minnesota Univ. (USA), PCC (Paris), SPP (S...

We present templates for the Sunyaev-Zel’dovich (SZ) angular power spectrum based on four models for the nonlinear gas distribution. The frequency-dependent SZ temperature fluctuations, with thermal (TSZ) and kinetic (KSZ) contributions, are calculated by tracing through a dark matter simulation, processed to include gas in dark matter halos and in the filamentary intergalactic medium. Differen...

Dark energy models due to a slowly evolving scalar (quintessence) field φ are studied for various potentials V (φ) in a universe with negative curvature. The potentials differ in whether they possess a minimum at φ = 0 or are monotonically declining, i. e. have a minimum at infinity. The angular power spectrum Cl of the cosmic microwave background (CMB) as well as the magnitude-redshift relatio...

We analyze the photometric redshift catalog of the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) to estimate the Fisher information in the galaxy angular power spectrum with the help of the Rimes-Hamilton technique. It is found that the amount of Fisher information contained in the galaxy angular power spectrum is saturated at lensing multipole scale 300 ≤ l ≤ 2000 in the redshift range 0....

High-energy photons from pair annihilation of dark matter particles contribute to the cosmic gamma-ray background (CGB) observed in a wide energy range. The precise shape of the energy spectrum of CGB depends on the nature of dark matter particles. In order to discriminate between the signals from dark matter annihilation and other astrophysical sources, however, the information from the energy...

Observational evidence for the presence of a preferred scale around 100 Mpc in the distribution of high-density regions in the Universe is summarised. Toy models with various degrees of regularity are analysed to understand better the observational data. Predictions of models which produce a feature on the initial power spectrum of matter are analysed and compared with new observational data on...

We present a measurement of the angular power spectrum of the cosmic microwave background (CMB) radiation observed at 148 GHz. The measurement uses maps with 1.′4 angular resolution made with data from the Atacama Cosmology Telescope (ACT). The observations cover 228 deg2 of the southern sky, in a 4. ◦2 wide strip centered on declination 53◦ south. The CMB at arcminute angular scales is particu...