Graduate How are parameters in inflation models tuned to align with CMB constraints?

Click For Summary
Parameters in inflation models are tuned to align with Cosmic Microwave Background (CMB) constraints using various software packages that compute the power spectrum based on cosmological parameters. Markov Chain Monte Carlo methods are commonly employed to establish the probability distribution from a likelihood function derived from experimental data. Both Planck and WMAP provide tools to assess the likelihood that a specific power spectrum corresponds with their CMB observations. Many inflation models, particularly those with inflection points in inflaton potentials, require careful tuning of multiple parameters. This process is essential for ensuring consistency with CMB constraints in the study of primordial black hole formation.
Rafid Mahbub
Messages
2
Reaction score
0
I have been studying primordial black hole formation through inflation for a while and I was curious to know how the parameters in an inflation model are determined such that they are consistent with CMB constraints. In my literature reviews, there are quite a few models that exhibit an inflection point in the inflaton potentials, but with quite a few parameters that need to be tuned. Is some kind of Markov Chain Monte Carlo method used to do this?
 
Space news on Phys.org
Rafid Mahbub said:
I have been studying primordial black hole formation through inflation for a while and I was curious to know how the parameters in an inflation model are determined such that they are consistent with CMB constraints. In my literature reviews, there are quite a few models that exhibit an inflection point in the inflaton potentials, but with quite a few parameters that need to be tuned. Is some kind of Markov Chain Monte Carlo method used to do this?
Typically, yes. One of a variety of software packages are used to compute the power spectrum given the set of cosmological parameters (many are listed here under the "CMB Tools" sub-header, confusingly the same as the header).

Then, some form of Monte Carlo chain is used to determine the probability distribution given a likelihood function (which stems from one or more experiments). Both Planck and WMAP supply software which can be used to calculate the likelihood that a given power spectrum matches their CMB data.
 
I always thought it was odd that we know dark energy expands our universe, and that we know it has been increasing over time, yet no one ever expressed a "true" size of the universe (not "observable" universe, the ENTIRE universe) by just reversing the process of expansion based on our understanding of its rate through history, to the point where everything would've been in an extremely small region. The more I've looked into it recently, I've come to find that it is due to that "inflation"...

Similar threads

  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 62 ·
3
Replies
62
Views
11K
  • · Replies 15 ·
Replies
15
Views
5K
Replies
5
Views
4K
  • · Replies 19 ·
Replies
19
Views
5K
  • · Replies 28 ·
Replies
28
Views
5K
Replies
127
Views
27K
  • · Replies 126 ·
5
Replies
126
Views
34K
  • · Replies 25 ·
Replies
25
Views
6K