Skip to main content

All Questions

3 votes
1 answer
65 views

Covariant and controvariant bases derivative

How to show that $\overrightarrow{\textbf{e}}_\sigma\cdot\partial_\mu \overrightarrow{\textbf{e}}_\nu = \overrightarrow{\textbf{e}}_\sigma\cdot\partial^\mu \overrightarrow{\textbf{e}^\nu}$ where $\...
Gigino's user avatar
  • 133
4 votes
3 answers
2k views

Laplace operator and tensor calculus:

I'm studying Tensor calculus and I found this interesting problem: Show that: $$ \Delta F=\frac{1}{\sqrt{\vert g\vert}}\partial_i\left(\sqrt{\vert g\vert} g^{ik}\partial_kF\right)$$ Here's some ...
user avatar
1 vote
4 answers
2k views

Deriving the Covariant Derivative of the Metric Tensor

First off, I did look through some other questions: Covariant Derivative of Metric Tensor Why is the covariant derivative of the metric tensor zero? https://math.stackexchange.com/q/2174588/ But they ...
M. V.'s user avatar
  • 81
0 votes
2 answers
3k views

Covariant Derivative of Metric Tensor

I'm an amateur studying General Relativity. I'm reading some notes of lectures by Susskind. In them, it is written that "we know that [the covariant derivative of the metric tensor] is zero. ...
davidp's user avatar
  • 113
0 votes
1 answer
75 views

Why $\Gamma^\mu_{\beta\delta;\gamma} =\Gamma^\mu_{\beta\delta,\gamma}$?

Gravitation Page 276 Exercise 11.3 solution indicated that $$\nabla_\gamma \nabla _\delta e_\beta =e_{\mu}\Gamma^\mu_{\beta\delta,\gamma} +(e_\nu\Gamma^\nu_{\mu\gamma}) \Gamma^\mu_{\beta\delta}$$ ...
ShoutOutAndCalculate's user avatar
0 votes
1 answer
354 views

Is Ricci's theorem can be simply deduced using covariant derivatives of fundamental tensors? [duplicate]

Well Ricci's theorem is given by: $$\mathrm{D}g_{ij}=\mathrm{D}g^{ij}=0$$ I was wondering that if the theorem can be proved using covariant derivatives of $\delta_i^k$, $g_{ij}$ and $g^{ik}$. I ...
user avatar
1 vote
0 answers
208 views

Lie derivative of the non-coordinate metric being 0

I'm trying to answer a question about a the Lie derivative of a metric in a non-coordinate basis. Here, the $C^{a}_{bc}$ are from the Lie derivative of one basis vector with respect to another, or ...
baker_man's user avatar
  • 420
1 vote
2 answers
519 views

Which derivative to use in the change of metric tensor due to a gauge transformation?

I'm used to calculating the change in the metric due to a gauge transformation in the following way: The gauge transformation up to linear order is \begin{equation} x^\mu \rightarrow x' ^\mu =x^\mu ...
P. C. Spaniel's user avatar
1 vote
2 answers
559 views

Calculate the expression of divergence in spherical coordinates $r, \theta, \varphi$

Hi this is my first question in [Physics.SE] I saw a lot of posts and I liked them. I hope that my question will be answered too. While I'm solving a problem in vector calculus. I recognized that I ...
user avatar
0 votes
0 answers
239 views

Covariant derivative of a metric determinant

The covariant derivative of a metric is zero $g_{\alpha\beta;\sigma}=0$. Is the covariant derivative of a metric determinant zero following the assumption($g_{\alpha\beta;\sigma}=0$): $$ g_{;\sigma}=...
Constantin's user avatar
0 votes
2 answers
827 views

Covariant derivative of four-position

May someone confirm or deny that covariant derivative of four-position is just metric tensor? I mean: $\nabla_{\gamma}X_{\alpha} = g_{\gamma \alpha}$ When I try to rewrite it with base vectors it ...
pog's user avatar
  • 9
0 votes
1 answer
2k views

Derivative of a metric tensor

I would like to ask you a question - maybe simple - but bothering me. We have two four-position vectors product in curvilinear coordinates given by $(1) \quad X^{\alpha}g_{\alpha \beta}X^{\beta} = \...
pog's user avatar
  • 9
0 votes
1 answer
1k views

Proof that covariant derivative of contravariant components of metric vanish for metric compatabilit

In this excercise I want to show that $\nabla_\rho g_{\mu \nu}=0$ and $\nabla_\rho g^{\mu \nu}=0$ This should probably be very easy, but excuse me I'm completly new to GR. So to do this I used that ...
higgshunter's user avatar
1 vote
0 answers
65 views

Differentiating the four-velocity contracted with itself

Let us denote $u^\mu$ as the contravarient component of a four velocity at a point in some coordinate system for a pseudo-Riemannian manifold. I want to examine the following equation. $$\partial_\nu(...
Nugi's user avatar
  • 541
0 votes
1 answer
173 views

4-velocity lowering index question

The 4-velocity in contravariant form is given by $$V^\mu=\frac{dx^\mu}{d\tau}$$ for some general co-ordinates $x^\mu$ and proper time $\tau$. Is the 4-velocity in covariant form given by $$V_\nu=V^\...
John Eastmond's user avatar

15 30 50 per page
1
3 4
5
6 7
9