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shinobi20

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- TL;DR Summary
- I am interested in knowing how to calculate the gravitational wave (GW) spectrum with inflation as a source, I have some background in inflation but I am not so familiar about calculating the GW spectrum.

I am interested in knowing how to calculate the gravitational wave (GW) spectrum with inflation as a source, I have some background in inflation but I am not so familiar about calculating the GW spectrum. I am reading a paper (https://arxiv.org/abs/0804.3249) about it, however, a big part of it is still over my head. I have some basic background in

Based on what I read, I must simultaneously calculate some differential equations (dynamical equations of density, Hubble parameter, etc) to produce a value for a certain parameter, in this case, ##H## (Hubble parameter) and then repeat the process for the perturbed value ##h_k##.

Another problem that came to mind is that how can I do the iteration in Mathematica, say, since ##H## will evolve through time, and ##h_k## has a differential equation containing ##H##, how do I calculate the data points of ##h_k## so as to plot the GW spectrum.

BTW, ##\Omega \propto h_k^2##.

Can anyone give me any advice on this? Also does anyone know of any tutorial (whether websites, papers, etc) that can give me more knowledge on this? Any help to point me in the proper direction would greatly help! Thanks!

*Mathematica*so I plan to use it to plot the spectrum.Based on what I read, I must simultaneously calculate some differential equations (dynamical equations of density, Hubble parameter, etc) to produce a value for a certain parameter, in this case, ##H## (Hubble parameter) and then repeat the process for the perturbed value ##h_k##.

Another problem that came to mind is that how can I do the iteration in Mathematica, say, since ##H## will evolve through time, and ##h_k## has a differential equation containing ##H##, how do I calculate the data points of ##h_k## so as to plot the GW spectrum.

BTW, ##\Omega \propto h_k^2##.

Can anyone give me any advice on this? Also does anyone know of any tutorial (whether websites, papers, etc) that can give me more knowledge on this? Any help to point me in the proper direction would greatly help! Thanks!