B Is an infinite universe compatible with cyclic models?

AI Thread Summary
Cyclic models, such as the Big Bounce, propose alternating periods of expansion and contraction, leading to a series of Big Bangs. An infinite universe raises challenges, as it would necessitate an infinite amount of matter to contract into a singularity, which appears implausible. The Big Bounce suggests that quantum phenomena trigger the bounce while maintaining finite density. This mechanism could theoretically occur throughout an infinite universe, similar to how a Big Bang might arise. The compatibility of infinite universes with cyclic models remains a complex topic in cosmology.
TheHeraclitus
Messages
14
Reaction score
1
TL;DR Summary
If space is flat and infinite are cyclic models possible? The answer seems intuitively no but I wonder if it's correct.
Cyclic models for reference.
I will take simple Big Bounce as an example of what I have in mind.
In Big Bounce there periods of expansion and periods of contraction which result in a never-ending series of Big Bangs. However if Universe is infinite in extent this would require infinite amount of matter would have to contract into one point but that seems impossible.
 
Space news on Phys.org
The big bounce implies that quantum things cause the bounce while the universe still has finite density. That could happen everywhere in a spacially infinite universe - in the same way that a big bang can.
 
  • Like
Likes TheHeraclitus
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...

Similar threads

Back
Top