If we imagine that after the Big Bang there was a "negative acceleration" for the action of the gravitational forces, similar to a bungee cord; at the absence of such forces the rope breaks and the acceleration of the body, that the elastic rope had restrained, becomes (for a "moment") positive to return immediately after negative. Our universe could not be in this peculiarity? In a positive acceleration between two long periods of negative acceleration?
I want to apologize a lot for posting this idea in your discussions. I am a newcomer in ResearchGATE and I do not know anything about physics, except what I read in popular magazines for my fun on the weekends. I did not realize the goals of the groups. I wanted to take advantage of my membership in the community (for my little experience in other fields) for questions and capricious born in the rest of Sunday. My apologies again
Dear Professor Maurizio Pea,
Our Universe is in expansion and this expansion can be separated in three main periods:
1- At the begining of the Universe (around 10^{-35}s), expansion undergoes a short period of acceleratetion. This is the inflation theory that has been first imagined in 1980 by Professor Alan Guth. It allows to solve several cosmological problem (like Universe flatness, causality and monopoles).
2 - Then Universe expansion decelerates until around 7 billions years ago.
3 - Seven billions years ago, expansion accelerates again because of dark energy.
It is possible that the present period of expansion acceleration be transcient, i.e. that the acceleration stop in the future and the expansion be decelerated again. However, the present standard cosmological model based on a dark energy described by a cosmological constant predicts that the acceleration will be forever.
Yours sincerely,
Stéphane
Dear Dr Stephane thank you very much for your kind and patient attention, best regards, Maurizio
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