Calculating Rii in Space with d-dimensions

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In summary, the conversation focused on a question about Riemannian tensor in a space with d-dimensions. The specific example given involved a linear element with a Gaussian tensor, K, and the question was about obtaining Rii. It was suggested that this was more of a mathematics homework problem rather than a question about relativity. The conversation also touched on the importance of understanding problems and subjects such as Riemannian geometry in general relativity. The conversation ended with a wish for good luck.
  • #1
Physicor
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Hello my friends

I have a question about riemannian tensor. how Get Rii in space with d-dimentions? for example in coordinate taht linear element is
ds^2=(dx^2+dy^2+dz^2)/[1+/(K/4)*(x^2+y^2+z^2)] where K is Gaussian tensor.

Thanks!:smile:
 
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  • #2
do you mean "curvature" for K?

In any case, as it stands, this isn't really a relativity question... it's more of a tensor or differential geometry question...but it really sounds like a mathematics homework problem. What is your starting point? Show some work first.
 
  • #3
Hi, Physicor,

I second what Rob said and add (if this is homework, I probably shouldn't) that you appear to have written down what might be the desired answer to a problem asking you to compute curvature of spatial hyperslices (orthogonal to the world lines of the matter) in an FRW model.
 
  • #4
But general Relativity depends this case. because when you talk about relativity, it is important that understanding some problems and subjects such as riemannian geometry & etc, specially for describtion of this answer that riemann proved it. there is a space with above line - element that K is gaussian curvature tensor (http://mathworld.wolfram.com/GaussianCurvature.html)

I can not understand this question " do you mean "curvature" for K? "

-------

thank u Chris Hillman. but my question didn't depend your answer.

____________

Good luck!
 

1. What is Rii in space?

Rii in space is a measure of the similarity between two variables in a d-dimensional space. It quantifies the strength of the relationship between two variables, with values ranging from 0 to 1, where 0 represents no relationship and 1 represents a perfect relationship.

2. What is the purpose of calculating Rii in space?

The purpose of calculating Rii in space is to understand the degree of relationship between two variables in a d-dimensional space. This can help in identifying patterns and making predictions in scientific research, such as in genetics, ecology, and social sciences.

3. How is Rii in space calculated?

Rii in space is calculated using a formula that takes into account the covariance and variances of the two variables in a d-dimensional space. The formula is: Rii = cov(Xi, Yi) / (var(Xi) * var(Yi)), where cov is the covariance and var is the variance.

4. What does a high or low Rii in space indicate?

A high Rii in space (close to 1) indicates a strong positive relationship between the two variables, meaning that as one variable increases, the other variable also tends to increase. On the other hand, a low Rii in space (close to 0) indicates a weak or no relationship between the two variables.

5. Can Rii in space be negative?

No, Rii in space cannot be negative as it measures the strength of the relationship between two variables, not the direction of the relationship. A positive Rii in space indicates a positive relationship, while a negative Rii in space indicates a negative relationship.

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