# Does anyone know which are Ricci and Riemann Tensors of FRW metric?

• physicsuniverse02
In summary, the conversation discusses the need to compare results of the Ricci and Riemann Tensors of the FRW metric, specifically in regards to the spatial coordinates. The speaker suggests looking up these results in references or using a computer package like Maxima. They also mention the possibility of posting the results for others to review. Some suggested resources for solving the Einstein equation are mentioned, including a journal article, a lecture notes document, a forum post, and a Wikipedia page.
physicsuniverse02
Homework Statement
Find Ricci and Riemann tensors of FRW metric
Relevant Equations
\begin{align*}g_{\mu\nu}=a(t)^2\begin{pmatrix} \frac{1}{1-kr^2} & 0 & 0 \\ 0 & r^2 & 0\\ 0 & 0 & r^2\sin^2{\theta} \end{pmatrix}\end{align*}
I just need to compare my results of the Ricci and Riemann Tensors of FRW metric, but only considering the spatial coordinates.

physicsuniverse02 said:
I just need to compare my results of the Ricci and Riemann Tensors of FRW metric, but only considering the spatial coordinates.
Then you should either look up those results in one of many references, or check your computation using a computer package designed for that purpose, like Maxima.

If you want someone here to take a look at your results and let you know if they make sense, you need to post them here. If you are expecting us to just tell you the answer here, you are expecting too much.

PhDeezNutz and vanhees71

## 1. What is the FRW metric?

The Friedmann-Robertson-Walker (FRW) metric is a mathematical model used to describe the expanding universe in the field of cosmology. It is a solution to Einstein's field equations in general relativity and is based on the assumption that the universe is homogeneous and isotropic on large scales.

## 2. What are the Ricci and Riemann tensors of the FRW metric?

The Ricci tensor and the Riemann tensor are two mathematical objects used in the study of general relativity. In the FRW metric, the Ricci tensor describes the curvature of spacetime, while the Riemann tensor describes the tidal forces experienced by objects in the universe.

## 3. How are the Ricci and Riemann tensors related in the FRW metric?

In the FRW metric, the Ricci tensor is directly proportional to the Riemann tensor. This means that changes in the Riemann tensor will result in corresponding changes in the Ricci tensor, and vice versa.

## 4. What is the significance of the Ricci and Riemann tensors in cosmology?

The Ricci and Riemann tensors play a crucial role in understanding the behavior of the universe on large scales. They are used to study the dynamics of the expanding universe and to make predictions about its future evolution.

## 5. Can the Ricci and Riemann tensors be used to determine the geometry of the universe?

Yes, the Ricci and Riemann tensors are important tools in determining the geometry of the universe. By studying their values and how they change over time, scientists can determine whether the universe is flat, open, or closed, and make predictions about its ultimate fate.

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