What is the definition of adiabatic CMb spectrum in simple inflationary models?

[skydivephil]

Can someone give a clear definition of what we mean when we say the CMb spectrum is adiabatic and what it means for simple infaltionary models?

 

[Mihael@@/&]

http://en.wikipedia.org/wiki/List_of_adiabatic_concepts

 

[skydivephil]

Thanks for that but I don't see cosmology or CMb research listed as one of those concepts.

 

[LithiumHelios]

It is usually used in the context of the density perturbations. In particular the density perturbations will be the same for all constituent components of the Universe:

$$\frac{\delta \rho_a}{(\rho_a + \bar{\rho})}$$ will be the same for all components (enumerated by 'a') where $$\bar{\rho}$$ is our mean background value. Have a quick glance at the http://en.wikipedia.org/wiki/Primordial_fluctuations" page.

 

[skydivephil]

Thanks

 

[LithiumHelios]

The alternatives to adiabatic are usually along the lines of 'isocurvature' fluctuations etc. Just in case you were interested here are a few interesting links:

http://arxiv.org/abs/astro-ph/9610219"

http://arxiv.org/abs/0907.0261"

http://arxiv.org/abs/0803.0547" (This has a clearer discussion than the 7yr or 3yr papers in my opinion. ; It's also well referenced so you can seek out other papers of interest etc.)

http://arxiv.org/abs/0812.3500"