I Can someone explain Quasi-steady-state cosmology to me?

[TheHeraclitus]

TL;DR Summary

Why is it called "Quasi steady-state" and not just Steady state?
How does it account for expansion of the universe?

I know it says Universe is eternal, how does that work with gravity? If all the stars and galaxies had infinite time to attract each other why are they still apart? I guess this is a naïve question because no one talks about it but I can't figure it out.

Thank you for answers!

 

[PeterDonis]

Can you give a reference for where you are getting your information about the quasi steady state model?

 

[Bandersnatch]

Basically, in steady-state there is exponential expansion driven by a repulsive field, and continuous creation of matter to keep the density of the universe constant.
In QSS there are pulsations between minimum and maximum radii (but not full contractions towards a singularity or near-singularity, and not necessarily simultaneously throughout the entire universe) with matter being created predominantly during the minima from the repulsive field.

In both cases the state of the universe today is representative of how it was for all time (i.e. the perfect cosmological principle - not only every place looks the same, but also every time). Although in the QSS case this condition is comparatively relaxed, with expansion->contraction->creation->expansion oscillations.

Good non-technical overview with lots of historical background:
https://arxiv.org/abs/1201.3449