Cosmological constant problem, interesting solution?

In summary, there are various opinions and theories being discussed regarding the cosmological constant problem. Some news outlets are reporting on a potential solution based on a recent paper that uses two scalar fields and arrives at a cutoff-scale close to the Planck scale. Others are exploring a different approach, using a quantum effective action and describing the Universe as a transition between fixed points of RG flow, which incorporates dark energy naturally. However, there are still debates and questions surrounding these theories and their compatibility with current observations in cosmology.
  • #1
windy miller
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Som news outlets are reporting a potential solution to the cosmological constant problem:
https://arxiv.org/pdf/1703.00543.pdf
opinions on this paper are much appreciated.
 
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Space news on Phys.org
  • #2
Here is a report from the university

It is interesting that their calculation (based on the observed cosmological constant) gives a cutoff-scale that is not too far away from the Planck scale. They just used two scalar fields, a more realistic field content would be interesting.
 
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  • #3
Here is a very interesting way of arriving at the cosmological constant.

http://nautil.us/issue/53/monsters/the-universe-began-with-a-big-melt-not-a-big-bang

A more detailed paper: https://arxiv.org/abs/1703.06144

regards
sunu
 
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  • #4
What do you think of Christof Wetterichs way? He uses a quantum effective action to describe the Universe (as a transition between fixed points of RG flow) where the Planck mass is described as a scalar field ("variable gravity"). This model (where masses decrease in time and the Universe shrinks) incorporates very naturally dark energy. See e.g. https://arxiv.org/pdf/1705.00552.pdf (one in a series of many papers on this model). As far as I understand it, in his model inflation and DE are just two manifestations of the same. He also claims that his model is compatible with all current observations in cosmology, but I'm not really convinced yet.
 

1. What is the Cosmological Constant Problem?

The Cosmological Constant Problem is a fundamental issue in cosmology that relates to the discrepancy between the predicted value of the cosmological constant in the equations of general relativity and the observed value of the cosmological constant in the universe.

2. What is the interesting solution to the Cosmological Constant Problem?

The interesting solution to the Cosmological Constant Problem is the concept of "cosmic inflation," which proposes that the early universe underwent a period of rapid expansion, causing the cosmological constant to approach zero. This solution helps to reconcile the predicted and observed values of the cosmological constant.

3. How does the interesting solution to the Cosmological Constant Problem explain the observed flatness of the universe?

The interesting solution posits that during the period of cosmic inflation, the universe expanded so rapidly that it became incredibly flat. This explains the observed flatness of the universe and supports the idea of cosmic inflation as a solution to the Cosmological Constant Problem.

4. Are there any other proposed solutions to the Cosmological Constant Problem?

Yes, there are other proposed solutions to the Cosmological Constant Problem, such as the anthropic principle, which suggests that our universe is one of many universes with different values for the cosmological constant, and we happen to live in the one with a small but nonzero value.

5. How does the Cosmological Constant Problem impact our understanding of the universe?

The Cosmological Constant Problem challenges our current understanding of the universe and highlights the need for a more comprehensive theory of gravity that can accurately predict the value of the cosmological constant. It also raises questions about the nature of dark energy, which is thought to be responsible for the observed acceleration of the universe's expansion.

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