1. BiGyElLoWhAt

    Tensors in GR

    Hi all, I'm fairly new to GR, and I'm also somewhat new to tensors as well. I'm looking for some detailed explaination of a tensor, as I want to begin studying GR mathematically. I watched a video that was posted on PF not too long ago that was pretty good. I'm having trouble remembering who it...
  2. T

    Tensor moment of inertia -- why is there a "-" sign?

    why there is a negative sign in the tensor moment of inertia??
  3. U

    Faraday Tensor Matrix Element

    The Faraday Tensor is given by: Consider the following outer product with the 4-potential: The Faraday Tensor is related to the 4-potential: F^{mn} = \Box^{m} A^n - \Box^n A^m For example, ## F^{01} = -\frac{1}{c} \frac{\partial A^x}{\partial t} - \frac{1}{c}\frac{\partial...
  4. 3

    MIT OCW Tensors

    Hello, I am working through the MIT OCW courses 8.01 and 8.012. At my university we already learned about tensors in the first mechanics course but I don't really understand them completely. Therefore I am searching for some MIT OCW course that covers tensors. I'd be glad at any help...
  5. P

    Tensor of inertia, half disk

    1. Homework Statement Half disk, radius R, mass m. I need the inertia tensor about the center of mass and then find the Principal moments of inertia about another coordinate system. Struggling with the product of inertia...
  6. sweetdreams12

    Tensor coordinate system help

    1. Homework Statement A tensor and vector have components Tαβγ, and vα respectively in a coordinate system xμ. There is another coordinate system x'μ. Show that Tαβγvβ = Tαβγvβ 2. Homework Equations umm not sure... ∇αvβ = ∂vβ/∂xα - Γγαβvγ 3. The Attempt at a Solution Tαβγvβ =...
  7. C

    Why can we not do algebraic methods like transposing with tensors

    Hello everyone! Even though I have done substantial tensor calculus, I still don't get one thing. Probably I am being naive or even stupid here, but consider $$R_{\mu\nu} = 0$$. If I expand the Ricci tensor, I get $$g^{\sigma\rho} R_{\sigma\mu\rho\nu} = 0$$. Which, in normal algebra, should...
  8. mef51

    [General Relativity] Prove that a tensor is a co-tensor

    Hello! I'd appreciate any help or pokes in the right direction. 1. Homework Statement Show that a co-tensor of rank 2, ##T_{\mu\nu}##, is obtained from the tensor of rank 2 ##T^{\mu\nu}## by using a metric to lower the indices: $$T_{\mu\nu} = g_{\mu\alpha}g_{\nu\beta}T^{\alpha\beta}$$ 2...