GR & The Cosmological Constant

[General_Relativity21]

When we approach a calculation in relativity, do we have to change the cosmological constant in order to work with bigger dimensions? Because i know we are limited to seeing 1, 2 and 3 dimensions, i was just curious if you wanted to figure out an answer using an equation based on a bigger dimension in relativity, i was guessing that the cos constant had to change also?

 

[Nereid]

Welcome to Physics Forums General_Relativity21!

This is an interesting question, and seems to relate strongly to GR, so I am moving the thread to the S&GR section, where I think you will quickly get a good answer.

 

[Crosson]

The setting of GR is four-dimensional spacetime. It is possible to work with fewer then four dimensions, but not more then four (in General Relativity).

The cosmological constant does not depend on the number of dimensions in which you are calculating.

 

[pervect]

Agreed, the cosmological constant has nothing to do with the number of dimensions in space-time. We work with 3 spatial dimensions and one time dimension in GR because that's what we see. Because space and time can "intermix" depending on the observer, we say that in GR we work with a 4-dimensional "space-time continuum".

 

[hellfire]

As far as I know you can define the Einstein-Hilbert action (which leads to general relativity) in more than 4 dimensions. I don’t know whether the cosmological constant remains unchanged or not, but it is for sure that possible interpretations of its nature change in such a case. May be this is a question for the string forum.