## Wednesday, February 17, 2016

### negative cosmological constant

could $\Lambda$ be negative? what consequences would that have for the evolution of FLRW-universes and would it be conceivable from a theoretical point of view?

#### 1 comment:

1. Sure.

A negative cosmological constant behaves opposite to matter in terms of curvature but similar to matter in terms of the expansion rate. So, a universe with a large (in absolute value) but negative cosmological constant would have negative spatial curvature and collapse relatively quickly.

From a theoretical point of view, why not? If one believes that the only source of the cosmological constant are vacuum-energy fluctuations, then perhaps a bit more difficult. I once heard a talk where the speaker said that from the ads/cft-correspondence point of view, it would make more sense if it were negative.