Expansion-Collapse cycle in cosmological structures?

In summary, cosmological structures such as galaxies, clusters of galaxies, and gas bodies can be attracted to each other by gravity if they are close enough, but can also be pushed further apart by the expansion of the universe if they are far enough apart. In some cases, these structures can detach from the expansion and start being pulled towards each other by gravity. There is a possibility that these structures may follow a cycle of expansion and contraction, but it has not been observed yet.
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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?
 
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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?
 

FAQ: Expansion-Collapse cycle in cosmological structures?

What is the Expansion-Collapse cycle in cosmological structures?

The Expansion-Collapse cycle refers to the theoretical model in which large-scale structures in the universe, such as galaxies and clusters of galaxies, undergo phases of expansion and contraction. This concept challenges the traditional view of a continuously expanding universe by suggesting that gravitational forces may lead to periodic collapses and re-expansions of these structures.

What evidence supports the Expansion-Collapse cycle theory?

Currently, the Expansion-Collapse cycle remains largely theoretical, with limited direct observational evidence. Some indirect support comes from the study of cosmic microwave background (CMB) radiation, large-scale structure surveys, and simulations of dark matter and dark energy dynamics. However, more data and refined models are needed to substantiate this theory.

How does the Expansion-Collapse cycle relate to dark energy and dark matter?

Dark energy and dark matter play crucial roles in the dynamics of the universe's expansion and potential collapse. Dark energy is thought to drive the accelerated expansion of the universe, while dark matter contributes to the gravitational forces that could trigger a collapse. The interplay between these two components is central to understanding whether an Expansion-Collapse cycle is feasible.

What are the implications of the Expansion-Collapse cycle for the ultimate fate of the universe?

If the Expansion-Collapse cycle theory is correct, it implies that the universe may not expand forever but instead undergo periodic phases of collapse and re-expansion. This cyclic model contrasts with other theories such as the Big Freeze, Big Crunch, or Big Rip, each of which predicts a different ultimate fate for the universe based on the dominance of dark energy or gravitational forces.

How does the Expansion-Collapse cycle impact our understanding of cosmology?

The Expansion-Collapse cycle introduces a new perspective on the evolution of the universe, suggesting a more dynamic and cyclical process rather than a linear one. It challenges existing models and encourages scientists to explore alternative mechanisms of cosmic evolution, potentially leading to new discoveries about the fundamental forces and components of the universe.

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