Is there any 2D surface whose metric tensor is eta?

In summary, a 2D surface with a metric tensor of -1 and 1 exists, such as two-dimensional flat spacetime or the worldsheet of a string. However, it is not possible to have this metric on a surface induced by its embedding in a higher-dimensional Euclidean space, as the metric tensor induced by an embedding in a Riemannian space will always be positive definite.
  • #1
arpon
235
16
Does there exist any 2D surface whose metric tensor is,
##\eta_{\mu\nu}=
\begin{pmatrix}
-1 & 0 \\
0 & 1
\end{pmatrix}##
 
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  • #2
Yes. Two-dimensional flat spacetime. Or the worldsheet of a string. What are you looking for in particular?
 
  • #3
haushofer said:
Yes. Two-dimensional flat spacetime. Or the worldsheet of a string. What are you looking for in particular?
I am looking for a surface in 'space'.
 
  • #4
Your question is unclear. If you are asking if you can get that metric on a two-dimensional surface induced by its embedding in a higher-dimensional Euclidean space, then no. The metric tensor induced by an embedding in a Riemannian space is going to be positive definite.
 
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  • #5
arpon said:
I am looking for a surface in 'space'.
You mean ordinary space? But you have a Lorentzian signature. Seems to me like looking for complex Majorana spinors.
 

Related to Is there any 2D surface whose metric tensor is eta?

1. What is a metric tensor?

A metric tensor is a mathematical object that describes the geometry and distance relationships on a curved surface or manifold. It is used in the field of differential geometry to measure lengths and angles on a surface.

2. What does eta represent in the metric tensor?

Eta (η) represents the components of the metric tensor in a specific coordinate system. It is a set of numbers that describe how distances and angles are measured on a 2D surface.

3. Can you give an example of a 2D surface with a metric tensor of eta?

Yes, a flat plane or Euclidean space is an example of a 2D surface with a metric tensor of eta. In this case, eta is equal to the Kronecker delta, which represents the Euclidean distance between two points on the plane.

4. Are there any other surfaces besides a flat plane that can have a metric tensor of eta?

Yes, other examples include a sphere, a cylinder, and a cone. However, the values of eta will be different for each of these surfaces as they have different curvature and distance relationships.

5. How is the metric tensor of a 2D surface determined?

The metric tensor for a 2D surface can be determined by calculating the inner product of tangent vectors at each point on the surface. This inner product gives the components of the metric tensor in a specific coordinate system.

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