## Einstein metric and Space-time metric

Hi there,

I have a few queries and they are as follows:

(i) What is the difference between the Einstein metric and the Space-time metric?

(ii) What does the curvature of the metric really mean? Does one calculate the Riemann curvature tensor, but what does that really tell you if it ends up 'a constant divided by r squared'?

(iii) In the context of string theory, why is it that the space-time metric ceases to be well defined once the curvature of the string metric is of order the string scale?
 PhysOrg.com science news on PhysOrg.com >> Leading 3-D printer firms to merge in $403M deal (Update)>> LA to give every student an iPad;$30M order>> CIA faulted for choosing Amazon over IBM on cloud contract
 Blog Entries: 4 Recognitions: Gold Member 1. the Einstein metric is an example of a space-time metric. It is cosmological solution of the field equations. 2. The Riemann tensor in 4-D has 44 components. Do you mean the Riemann scalar ? If the scalar is as you describe it, it means that the curvature scalar decreases as 1/r2 3. Because the strings would bend. I suspect the strings need a locally flat space-time. The size of a locally flat patch decreases with the curvature.

 Similar discussions for: Einstein metric and Space-time metric Thread Forum Replies General Physics 0 General Physics 1 Quantum Physics 2