Inside the big bang were their other sub big bangs?

In summary, the scenario proposed by the authors involves a contracting universe that undergoes a bounce, which resolves the big-bang singularity. As the sound speed of cold dark matter is varied, the amplitude of the scalar perturbations depends on a combination of these factors. This scenario could give a definitive answer to the question of whether inflationary models are correct or not.
  • #1
tlain123
2
0
As the question says. Sorry if it seems like a dum question!
 
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  • #2
The question does not make sense. What is "inside" the big bang, and what is "not inside"?
What would a "sub big bang" be?

The most likely answer is "no", but phrased like this the question does not make sense.
 
  • #3
Probably no.
 
  • #4
tlain123 said:
As the question says. ...

There is no one unique consensus view as to how expansion got started, and what conditions preceded the start of expansion.

So the words "big bang" do not have an established meaning---if you apply them to right at the start of expansion.

Better you should say what YOU mean by a "big bang" before you ask the question.

I don't ordinarily use that term because it's so vague as to be meaningless, but if I did I would give a reference to some professional research paper that describes one version of the start of expansion which is being studied. Like for example I might give a link to this, just to be specific:
http://arxiv.org/abs/1412.2914
A ΛCDM bounce scenario
Yi-Fu Cai, Edward Wilson-Ewing
(Submitted on 9 Dec 2014)
We study a contracting universe composed of cold dark matter and radiation, and with a positive cosmological constant. As is well known from standard cosmological perturbation theory, under the assumption of initial quantum vacuum fluctuations the Fourier modes of the comoving curvature perturbation that exit the (sound) Hubble radius in such a contracting universe at a time of matter-domination will be nearly scale-invariant. Furthermore, the modes that exit the (sound) Hubble radius when the effective equation of state is slightly negative due to the cosmological constant will have a slight red tilt, in agreement with observations. We assume that loop quantum cosmology captures the correct high-curvature dynamics of the space-time, and this ensures that the big-bang singularity is resolved and is replaced by a bounce. We calculate the evolution of the perturbations through the bounce and find that they remain nearly scale-invariant. We also show that the amplitude of the scalar perturbations in this cosmology depends on a combination of the sound speed of cold dark matter, the Hubble rate in the contracting branch at the time of equality of the energy densities of cold dark matter and radiation, and the curvature scale that the loop quantum cosmology bounce occurs at. Importantly, as this scenario predicts a positive running of the scalar index, observations can potentially differentiate between it and inflationary models. Finally, for a small sound speed of cold dark matter, this scenario predicts a small tensor-to-scalar ratio.
14 pages, 8 figures.
 
  • #5
Okay, thankyou for your help. Apologies for the confusion of the question. I'm 15 and curious!
 

FAQ: Inside the big bang were their other sub big bangs?

What is the big bang theory?

The big bang theory is a scientific explanation for the origin and development of the universe. It proposes that the universe began as a singularity, a point of infinite density and temperature, and has been expanding and cooling ever since.

How did the big bang happen?

According to the big bang theory, the universe began with a rapid expansion from a singularity. This expansion is known as inflation and is thought to have occurred in a fraction of a second. After inflation, the universe continued to expand and cool, eventually forming the galaxies and structures we see today.

Were there other sub big bangs inside the big bang?

The concept of sub big bangs, or smaller events occurring within the big bang itself, is still a topic of debate among scientists. Some theories propose that there may have been other phases or events within the big bang, but there is currently no conclusive evidence for this.

How do we know about the big bang?

Scientists use a variety of evidence to support the big bang theory, including observations of the cosmic microwave background radiation, the abundance of light elements in the universe, and the redshift of galaxies. These pieces of evidence, along with mathematical models and simulations, all support the idea of the big bang.

What existed before the big bang?

The concept of "before" the big bang is still a topic of debate and there is no consensus among scientists. Some theories propose that the universe has always existed in some form, while others suggest that the concept of time itself may not apply before the big bang. Ultimately, our current understanding of the universe is limited by our ability to observe and study it, so the answer to this question may remain a mystery.

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