Big Rip Cosmology and Many-Worlds Quantum Mechanics

[caspiansea3]

My question is based on two theoretical assumptions. 1) The universe continues with its expansion resulting in an eventual "Big Rip". 2)The many-worlds interpretation of quantum mechanics is correct. In this scenario will all the "branches of reality" in the many-worlds undergo the "Big Rip" or will some branches undergo a different outcome?

 

[phinds]

My question is based on two theoretical assumptions. 1) The universe continues with its expansion resulting in an eventual "Big Rip". 2)The many-worlds interpretation of quantum mechanics is correct. In this scenario will all the "branches of reality" in the many-worlds undergo the "Big Rip" or will some branches undergo a different outcome?

I don't believe in the "many worlds" so can't help you there but the "big rip" has long been considered unrealistic by most physicists. The expansion of the universe will continue to accelerate but there is no evidence that objects as gravitationally bound as galaxies will expand, they will just eventually go cold and dark.

 

[Drakkith]

The Many Worlds Interpretation is exactly that. An interpretation. The actual theory makes no distinction between the different interpretations. In any case, even if it were true, it's just talking about the probabilities involved in QM. So as far as I know every reality would undergo the same general evolution.

 

[bapowell]

The big rip is the expected fate of the universe if the energy density driving the accelerated expansion is increasing in time. Current observations have not confirmed that this is the case -- the accelerated expansion of recent times could well be the result of a cosmological constant. So the big rip is not a working assumption in the concordance cosmological model.

Energy that absurdly increases in density is called phantom energy: it is quantum mechanically unstable and so any description in terms of fundamental particles/fields is likely doomed to failure. There is some room for understanding phantom energy as an emergent or effective phenomenon, but there's little cause to worry about these things until we get a better observational handle on the nature of the accelerated expansion.