## Wednesday, February 25, 2015

### recollapsing FLRW-universes

can you construct a FLRW-universe with dark matter and dark energy (with constant equation of state $w$) that recollapses? what's a suitable condition?

#### 2 comments:

1. Sure. Lambda negative or lambda positive but $alpha$ less than 1. (See the paper by Lake on the flatness problem for a description of $alpha$.)

2. Additional constraint: q must be positive. If it is negative, the model is a bounce model which, if expanding now, will not recollapse. (For non-bounce models, it should be "collapse" and not "recollapse", similar to how it should be "combination" and not "recombination".