How inflation can give rise to irregularities

houhou.trad

I can understand how can inflation give rise to the isotropy of the CMB, but that it can give rise also to the irregularities in the CMB...!?
Please, can any one explain me this?
thanks.

Chalnoth

Well, the quantum fluctuations in the field that drives inflation get blown up by the rapid expansion to tremendous scales. These teeny tiny quantum fluctuations, then, become the seeds that grow to form the differences in temperature we see in the CMB.

Cosmo Novice

What a nice and succinct answer!

lpetrich

Inflation is exponential expansion, and this expansion makes nearby parts of the Universe gets dragged across one's event horizon. Quantum fluctuations are no exception. They get frozen into place when they get stretched beyond the event-horizon size. Beyond that size, there is no way to communicate across the fluctuation's size.

When it stops, then distant parts of the Universe can return across one's event horizon.

Inflation and the CMB - C.H. Lineweaver
An Exposition on Inflationary Cosmology - G.S. Watson

BillSaltLake

Exclusive of later effects like baryon acoustic oscillations, what are the estimated values of primordial fluctuations in the fractional value of ρ that lead to the observed CMB? For example, over a distance equivalent to 10 Glyr now, was the early variation something like an abiabatic 1 part in 10⁵? Any papers on this?

houhou.trad

thank you every body