A perfect fluid?
Modern cosmology is obliged to reconsider its historical opinion on the huge empty regions that we label with a generic name: "Vacuum".
This is due to the fact that the actual astronomical observations lead to a surprising conclusion: these regions "carry" approximately 69% of the energy contained in our universe.
And this is the source for one of the most important crisis in fundamental physics since we have absolutely no idea on the effective nature of these regions.
Recent scientific articles envisage that the empty regions of our universe are behaving like perfect fluid. We not yet have enougth arguments to promote a definitive conclusion.
A long time ago, I have explored what appears to be a complementary hypothesis; precisely: "What happens in our mathematics if we consider that the material part of our universe is behaving like an elastic string (i.e.: a string with a coefficient of elasticity) either in expansion or in retraction?
Unexpectidly, the equation of state (EoS) for a perfect fluid can be recovered!
The simplest configuration can then be extended to more complicated ones.
You can read the document "Vacuum and Strings"
Please visit: https://www.researchgate.net/profile/Thierry_Periat
If you don't have access here, discover the first steps of my approach on the following page:
The early hours (a simplified version is available there).
Thierry PERIAT, 09 July 2018