scholarly journals RÉNYI FUNCTION FOR MULTIFRACTAL RANDOM FIELDS

Fractals ◽  
2013 ◽  
Vol 21 (02) ◽  
pp. 1350009 ◽  
Author(s):  
NIKOLAI N. LEONENKO ◽  
NARN-RUEIH SHIEH
Keyword(s):  
Cosmic Microwave Background ◽  
Spherical Harmonics ◽  
Random Fields ◽  
Background Radiation ◽  
Microwave Background ◽  
Basic Scheme ◽  
Infinite Products ◽  
Microwave Background Radiation ◽  
Log Normal ◽  
Isotropic Random

This paper presents the basic scheme and the log-normal, log-gamma and log-negative-inverted-gamma scenarios to establish the Rényi function for infinite products of homogeneous isotropic random fields on Rn; in particular for random fields on the sphere in R3. The motivation of this paper is the test of (non-)Gaussianity on the Cosmic Microwave Background Radiation (CMBR) in Cosmology. In the presentation, we need to employ spherical harmonics for some concrete computations.

scholarly journals Revisiting cosmic microwave background radiation using blackbody radiation inversion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Koustav Konar ◽  
Kingshuk Bose ◽  
R. K. Paul
Keyword(s):  
Temperature Distribution ◽  
Cosmic Microwave Background ◽  
Background Radiation ◽  
Big Bang ◽  
Blackbody Radiation ◽  
Microwave Background ◽  
Background Spectrum ◽  
Microwave Background Radiation ◽  
Mathematical Process

AbstractBlackbody radiation inversion is a mathematical process for the determination of probability distribution of temperature from measured radiated power spectrum. In this paper a simple and stable blackbody radiation inversion is achieved by using an analytical function with three determinable parameters for temperature distribution. This inversion technique is used to invert the blackbody radiation field of the cosmic microwave background, the remnant radiation of the hot big bang, to infer the temperature distribution of the generating medium. The salient features of this distribution are investigated and analysis of this distribution predicts the presence of distortion in the cosmic microwave background spectrum.

Statistics of Cosmic Microwave Background Radiation with the Cosmic String Model

1997 ◽  
Vol 06 (05) ◽  
pp. 535-544
Author(s):  
Petri Mähönen ◽  
Tetsuya Hara ◽  
Toivo Voll ◽  
Shigeru Miyoshi
Keyword(s):  
Cosmic Microwave Background ◽  
Cosmic String ◽  
Large Scale ◽  
Background Radiation ◽  
Unit Length ◽  
Angular Size ◽  
Cosmic Microwave Background Radiation ◽  
Density Parameter ◽  
Microwave Background ◽  
Microwave Background Radiation

We have studied the cosmic microwave background radiation by simulating the cosmic string network induced anisotropies on the sky. The large-angular size simulations are based on the Kaiser–Stebbins effect calculated from full cosmic-string network simulation. The small-angular size simulations are done by Monte-Carlo simulation of perturbations from a time-discretized toy model. We use these results to find the normalization of μ, the string mass per unit length, and compare this result with one needed for large-scale structure formation. We show that the cosmic string scenario is in good agreement with COBE, SK94, and MSAM94 microwave background radiation experiments with reasonable string network parameters. The predicted rms-temperature fluctuations for SK94 and MSAM94 experiments are Δ T/T=1.57×10-5 and Δ T/T=1.62×10-5, respectively, when the string mass density parameter is chosen to be Gμ=1.4×10-6. The possibility of detecting non-Gaussian signals using the present day experiments is also discussed.

scholarly journals Cosmological Applications of Hα Surveys

1998 ◽  
Vol 15 (1) ◽  
pp. 111-117 ◽  
Author(s):  
David Valls–Gabaud
Keyword(s):  
Cosmic Microwave Background ◽  
Background Radiation ◽  
Massive Stars ◽  
High Redshift ◽  
Formation Rate ◽  
Cosmic Microwave Background Radiation ◽  
Microwave Background ◽  
Microwave Background Radiation

AbstractWe briefly review three main applications of Hα surveys in cosmology, namely: (1) the diffuse Hα emission as a tracer of the free–free foreground that contaminates the fluctuations in the cosmic microwave background radiation; (2) the Hα emission from galaxies as a measure of the formation rate of massive stars, both at low and high redshift; and (3) the diffuse Hα emission from ionised clouds as a constraint on the local ionising background radiation.

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