I Cosmological constant problem, interesting solution?

AI Thread Summary
Recent discussions highlight a potential solution to the cosmological constant problem, referencing a paper that suggests a cutoff-scale near the Planck scale using two scalar fields. The conversation includes a mention of an alternative perspective by Christof Wetterich, who proposes a model where the Planck mass acts as a scalar field, leading to a unified description of dark energy and inflation. This model claims compatibility with current cosmological observations, although skepticism remains regarding its validity. The exploration of different field contents and their implications for understanding the universe is emphasized. Overall, the discourse reflects ongoing interest in innovative approaches to resolving fundamental cosmological issues.
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
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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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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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.
 
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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##.
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