Expansion-Collapse cycle in cosmological structures?

Click For Summary
SUMMARY

The discussion centers on the cyclical behavior of cosmological structures, specifically whether galaxies and superclusters can alternate between expansion and contraction phases. Participants explore the concept that, under certain conditions, these structures may detach from the universe's expansion and become gravitationally attracted to one another. The possibility of a repeating cycle of expansion and contraction, akin to the Hubble flow, is questioned, with a request for observational evidence or references supporting this phenomenon.

PREREQUISITES
  • Understanding of gravitational forces in cosmology
  • Familiarity with the Hubble flow and its implications
  • Knowledge of cosmological structures such as galaxies and superclusters
  • Basic principles of cosmic expansion and contraction
NEXT STEPS
  • Research the Hubble flow and its role in cosmic expansion
  • Investigate gravitational interactions between cosmological structures
  • Examine observational studies related to the expansion-collapse cycle
  • Explore theories of dark energy and its effects on cosmic structures
USEFUL FOR

Astronomers, cosmologists, and astrophysicists interested in the dynamics of cosmic structures and the implications of gravitational interactions in the universe.

Suekdccia
Messages
352
Reaction score
30
TL;DR
Expansion-Collapse cycle in cosmological structures: Is it possible?
Concerning cosmological structures (like galaxies, clusters of galaxies, gas bodies, superclusters...etc) if the elements that make them are close enough they will be attracted towards each other by gravity. Contrarily, if they are sufficiently far apart they will get further away following the expansion of the universe.

However, sometimes, even if objects follow the expansion of the universe, under some conditions, they can "de-attach" from it and start being attracted to each other by gravity.

Is it possible that these cosmological structures may follow a cycle between expansion and contraction? I mean, is it possible that a structure expands with the Hubble flow, then it stops and starts shrinking, and then, somehow, after collapsing, starts following the Hubble flow repeating this cycle indefinitely? Has this been ever observed?
 
  • Skeptical
Likes   Reactions: PeroK
Space news on Phys.org
Suekdccia said:
sometimes, even if objects follow the expansion of the universe, under some conditions, they can "de-attach" from it and start being attracted to each other by gravity.
Do you have a reference for this?
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 0 ·
Replies
0
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 19 ·
Replies
19
Views
2K
  • · Replies 25 ·
Replies
25
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 23 ·
Replies
23
Views
2K