CMB Angular Distribution: Understanding Gaussian Random Fields

AI Thread Summary
The discussion centers on the Cosmic Microwave Background (CMB) and its angular distribution being modeled as a Gaussian random field (GRF). Participants seek clarification on the origins of this classification and the geometric implications of GRFs. They reference key CMB data from COBE, WMAP, and PLANCK, emphasizing the importance of the CMB power spectrum in analysis. The conversation also highlights the need for a deeper understanding of GRFs, with participants sharing various resources for further study. Ultimately, the discussion aims to unravel the mechanisms that allow the CMB to be approximated as a Gaussian random field.
Madster
Messages
22
Reaction score
0
Dear all,

I don't understand why the Cosmic Microwave Background's angular distribution is considered to to a Gaussian random field initially.
The rest of the analysis is roughly clear to me, COBE/WMAP/PLANCK measure the CMB Photons and show the temperature fluctuations w.r.t. the mean temperature. On this data a spherical analysis is applied... But where does the GRF come from? What is b.t.w. a geometrical meaning of a GRF?

Thank you very much
 
Space news on Phys.org
Mordred said:
This article may help you hope your math is good lol

http://www.astro.rug.nl/~weygaert/tim1publication/lss2007/computerIII.pdf

the main usage in the CMB is in measurements of the CMB power spectrum.

thanks, my math is sufficient enough to get the script. So still what mechanism makes the CMB a gaussian random field, or to be more precise, let's us initially approximate the description with a GRF and look for fluctuations?
 
Last edited by a moderator:

Thread 'Matter density right after the decoupling'

https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
View full post »

Thread 'Rutgers finds a transparent Einstein Cross - apparently a dark matter "halo".'

The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
View full post »

Thread 'Big Bang and Infinite Universe'

Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...
View full post »

Similar threads

I Cosmic Flatness Deduced from CMB
Replies
4
Views
2K
I The CMB drag on an object moving through space
Replies
6
Views
2K
I Some questions about Cosmic Microwave Background radiation
Replies
13
Views
6K
B Is the Hawking-Hartle Euclidean approach confirmed by CMBR data?
Replies
13
Views
3K
What Is the Next Step in Inflation Theory?
Replies
11
Views
3K
A Thermal Field Theory: Calculating Angular Distribution of CMB
Replies
3
Views
1K
Penrose Gurzadyan fire back: new paper today
Replies
19
Views
7K
I Why Can We Still Observe the Cosmic Microwave Background?
Replies
7
Views
2K
How did the CMB Lorentz frame get chosen?
Replies
5
Views
3K
I Is There a Preferred Axis in Cosmology and What Could Be Its Origin?
Replies
8
Views
2K

Hot Threads

Recent Insights

Back
Top