CMB ANISOTROPY AND POLARIZATION MEASUREMENTS WITH RATAN-600

1999 ◽  
Vol 08 (05) ◽  
pp. 581-605 ◽  
Author(s):  
P. NASELSKY ◽  
I. NOVIKOV ◽  
YU. PARIJSKIJ ◽  
P. TCIBULEV
Keyword(s):  
Dark Matter ◽  
Cosmological Model ◽  
Cosmic Microwave Background ◽  
Radio Telescope ◽  
Cold Dark Matter ◽  
Special Astrophysical Observatory ◽  
Microwave Background ◽  
Antenna Beam ◽  
Polarization Measurements

Some aspects of the Cosmological Gene project and the possibilities of the measurements of the Cosmic Microwave Background (CMB) anisotropy and polarization using the radio-telescope RATAN-600 (Special Astrophysical Observatory) are discussed. We study different strategies of the measurements and present main parameters of the antenna beam for these strategies at the frequency diapason ν=1–30 GHz. We simulate Cosmological Gene observations using a standard Cold Dark Matter cosmological model. We quantify the distortions of the primordial CMB-signal in the RATAN-600 scans by the atmosphere emission, foreground and noise in RATAN-600 scans. We emphasize that RATAN-600 is the unique instrument which allows the investigation of anisotropy and polarization of the CMB and investigate foreground and noise up to the multipole numbers l ∝ 105.

scholarly journals Cosmic Microwave Background as a Thermal Gas of SU(2) Photons: Implications for the High-z Cosmological Model and the Value of H0

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Steffen Hahn ◽  
Ralf Hofmann
Keyword(s):  
Dark Matter ◽  
Cosmological Model ◽  
Cosmic Microwave Background ◽  
Cold Dark Matter ◽  
Formal Solution ◽  
Planck Scale ◽  
Low Frequency ◽  
Hubble Constant ◽  
Microwave Background ◽  
Photon Gas

Presently, we are facing a 3σ tension in the most basic cosmological parameter, the Hubble constant H0. This tension arises when fitting the Lambda-cold-dark-matter model (ΛCDM) to the high-precision temperature-temperature (TT) power spectrum of the Cosmic Microwave Background (CMB) and to local cosmological observations. We propose a resolution of this problem by postulating that the thermal photon gas of the CMB obeys an SU(2) rather than U(1) gauge principle, suggesting a high-z cosmological model which is void of dark-matter. Observationally, we rely on precise low-frequency intensity measurements in the CMB spectrum and on a recent model independent (low-z) extraction of the relation between the comoving sound horizon rs at the end of the baryon drag epoch and H0 (rsH0=const). We point out that the commonly employed condition for baryon-velocity freeze-out is imprecise, judged by a careful inspection of the formal solution to the associated Euler equation. As a consequence, the above-mentioned 3σ tension actually transforms into a 5σ discrepancy. To make contact with successful low-z  ΛCDM cosmology we propose an interpolation based on percolated/depercolated vortices of a Planck-scale axion condensate. For a first consistency test of such an all-z model we compute the angular scale of the sound horizon at photon decoupling.

Limits on cold dark matter cosmologies from new anisotropy bounds on the cosmic microwave background

1991 ◽  
Vol 372 ◽  
pp. L1 ◽  
Author(s):  
Nicola Vittorio ◽  
Peter Meinhold ◽  
Philip Lubin ◽  
Pio Francesco Muciaccia ◽  
Joseph Silk
Keyword(s):  
Dark Matter ◽  
Cosmic Microwave Background ◽  
Cold Dark Matter ◽  
Microwave Background

scholarly journals CMB anisotropy science: a review

2012 ◽  
Vol 8 (S288) ◽  
pp. 42-52 ◽  
Author(s):  
Anthony Challinor
Keyword(s):  
Dark Matter ◽  
Cosmological Model ◽  
Cosmic Microwave Background ◽  
Gravitational Waves ◽  
Early Universe ◽  
Critical Role ◽  
Microwave Background ◽  
Fundamental Physics ◽  
Standard Cosmological Model

AbstractThe cosmic microwave background (CMB) provides us with our most direct observational window to the early universe. Observations of the temperature and polarization anisotropies in the CMB have played a critical role in defining the now-standard cosmological model. In this contribution we review some of the basics of CMB science, highlighting the role of observations made with ground-based and balloon-borne Antarctic telescopes. Most of the ingredients of the standard cosmological model are poorly understood in terms of fundamental physics. We discuss how current and future CMB observations can address some of these issues, focusing on two directly relevant for Antarctic programmes: searching for gravitational waves from inflation via B-mode polarization, and mapping dark matter through CMB lensing.

Sign in / Sign up

Export Citation Format

Share Document