Vacuum Energy Measurements Q

[EdEarl]

 

Wikipedia

Vacuum energy is an underlying background energy that exists in space throughout the entire Universe.

Clearly the vacuum energy has not been measured everywhere. Can I assume the vacuum energy is more or less constant everywhere, or is it possible some places have a different vacuum energy than other places?

[swansont]

You can reduce the vacuum energy in small gaps between conductive surfaces. That gives rise to the Casimir force. But otherwise, being the same everywhere seems to be a reasonable assumption. Pointless, in a way, since you can't tap into it.

[EdEarl]

I know you can't tap into it. I was reading about the vacuum catastrophe, and wondered if vacuum energy is different in space, distant from a gravity well, around a black hole, etc.

[Mordred]

It depends on the system. For example a vacuum has a pressure gradient near sources of mass.

 

However on sufficiently large enough scales it uniform in distribution.

 

Ie there is no pressure gradient on cosmological scales.