Cosmic Slow Down: Is Dark Energy Variable?

[skydivephil]

A paper appeared on the arxiv today claiming that the acceleration of the universe is slowing down:

http://uk.arxiv.org/abs/1306.0779

they reference a few other papers also claiming to see the same thing.

How robust do we think these reuslts are? If so what does it mean for dark energy being something variable rather than a cosmological constant?

 

[marcus]

I'm taking a wait-and-see attitude on that one. Just as a BTW side observation you might want to look up the authors e.g.
http://inspirehep.net/author/V.H.Cardenas.1/
He's the one whose name I recognize (21 papers, avg. no. cites = 4.0 excl. self-cite)
The other two have no prior papers listed on Inspire.
========================

The paper they CITE is by Starobinsky et al. Starobinsky is well-known and that paper has over 100 cites.
http://inspirehep.net/record/816682?ln=en
http://arxiv.org/abs/arXiv:0903.5141

I thought it might be worth looking at the list of cites of the Staro. paper to see which recent papers have RESPONDED to it. I took a quick look and didn't see anything interesting. There was a 2011 paper by Starobinsky himself et al, but it was somewhat more reserved and tentative, or so I thought.

My impression FWIW is that nothing much has come of this so far.

 

[skydivephil]

Thanks Marcus, I guess that new paper is only out today so we shall see if anyone takes it seriously.
If it were to be confirmed what would it imply for the cosmological constant - not so constant after all? or could we explain the slow down via other effects?

 

[Mordred]

Looking over the paper it seems to indicate a variable constant however they used a limitted data set, some of the reference sets were fairly old. So based exclusively on this article I wouldn't think it will go far but that is just my take on it.

 

[sardar]

I am always cautious when interpreting new research and findings, especially in the field of cosmology where there are still many unknowns. While the paper referenced on arxiv does present some interesting data and analysis on the slowing down of the universe's acceleration, it is important to note that this is just one study and more research is needed to confirm these results.

The concept of dark energy being variable rather than a cosmological constant is a fascinating one and has been explored by many researchers in the past. However, it is still a highly debated and controversial topic in the scientific community. The idea of a variable dark energy challenges our current understanding of the universe and its evolution, and therefore requires strong evidence and multiple studies to support it.

In terms of the robustness of these results, it is important to consider the methods and data used in the study. Are there any potential biases or errors that could affect the conclusions? Can the results be replicated by other studies using different methods and data? These are important questions that need to be addressed before we can confidently accept the idea of a variable dark energy.

If these results are indeed robust, it could have significant implications for our understanding of the universe and its expansion. It could mean that our current model of a cosmological constant needs to be revised, or that there are other unknown factors at play that affect the acceleration of the universe. Further research and analysis will be crucial in determining the validity of these findings and their implications for our understanding of dark energy.

In conclusion, while the idea of a variable dark energy is intriguing, it is important to approach these new results with caution and continue to gather more evidence and data to support or refute them. Science is a continuous process of questioning and testing, and only through rigorous research and analysis can we advance our understanding of the universe and its mysteries.