Transformation rules for vielbein and spin connection

In summary, the conversation discusses a homework assignment on deriving transformation rules for vielbein and spin connection. The conversation also mentions using certain equations and a covariant derivative, but the speaker admits to not fully understanding them and asks for advice and recommended textbooks.
  • #1
Steve Rogers
9
2
Homework Statement
Derive the following transformation rules for vielbein and spin connection:

$$\delta e_a^\mu=(\lambda^\nu\partial_\nu e_a^\mu-e_a^\nu\partial_\nu\lambda^\mu)+\lambda_a^b e_b^\mu$$

$$\delta\omega_a^{bc}=\lambda^\mu\partial_\mu\omega_a^{bc}+(-e_a^\mu\partial_\mu\lambda^{bc}+\omega_a^{d[b}\lambda_d^{c]}+\lambda_a^d\omega_d^{bc})$$
Relevant Equations
$$[M_{ab},X_c]=X_{[a}\eta_{b]c}$$

$$[M_{ab},M^{cd}]=-\delta_{[a}^{[c}M_{b]}^{d]}=-\delta_a^c M_b^d+\delta_b^c M_a^d+\delta_a^d M_b^c-\delta_b^d M_a^c$$
I am taking a course on General Relativity. Recently, I was given the following homework assignment, which reads

> Derive the following transformation rules for vielbein and spin connection:

$$\delta e_a^\mu=(\lambda^\nu\partial_\nu e_a^\mu-e_a^\nu\partial_\nu\lambda^\mu)+\lambda_a^b e_b^\mu$$

$$\delta\omega_a^{bc}=\lambda^\mu\partial_\mu\omega_a^{bc}+(-e_a^\mu\partial_\mu\lambda^{bc}+\omega_a^{d[b}\lambda_d^{c]}+\lambda_a^d\omega_d^{bc})$$

I was instructed to use:
$$[M_{ab},X_c]=X_{[a}\eta_{b]c}$$
and
$$[M_{ab},M^{cd}]=-\delta_{[a}^{[c}M_{b]}^{d]}=-\delta_a^c M_b^d+\delta_b^c M_a^d+\delta_a^d M_b^c-\delta_b^d M_a^c.$$
Also, the professor told us to consider the covariant derivative
$$\nabla_a=e_a^\mu\partial_\mu+\frac{1}{2}\omega_a^{bc}M_{cb}$$
To be honest, I have no idea what these symbols are (after examining my GR lecture note carefully). And most frustratingly, even if I have taken a one-year course on differential geometry (mathematical rigor), I still know nothing about the covariant derivative above. What on Earth do these symbols stand for? Is there any standard textbook that can help a GR beginner like me? I came here for some advice, please. Thank you very much.
 
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  • #3
Thank you. The chapter you mentioned does contain some information about vielbein, but to crack the problem, I need to find the variations of ##e_a^\mu## and ##\omega_a^{bc}##. This confuses me a lot because those ##\lambda##'s and partial derivatives in the formulas came out of nowhere.
 

FAQ: Transformation rules for vielbein and spin connection

What are vielbeins and spin connections?

Vielbeins and spin connections are mathematical objects used in the study of differential geometry, particularly in the field of general relativity. Vielbeins are a set of four linearly independent vectors that form a basis for the tangent space at each point in a curved space-time. Spin connections, on the other hand, are mathematical connections that describe how vielbeins change as they are transported between different points in the curved space-time.

What is the purpose of transformation rules for vielbeins and spin connections?

The transformation rules for vielbeins and spin connections are used to describe how these mathematical objects change under a change of coordinates. In other words, they allow us to relate the vielbeins and spin connections in one coordinate system to those in another coordinate system, which is necessary for making calculations and predictions in general relativity.

How do the transformation rules for vielbeins and spin connections differ from each other?

The transformation rules for vielbeins and spin connections differ in terms of the mathematical objects they are applied to. The transformation rules for vielbeins relate the components of the vielbein in one coordinate system to those in another coordinate system, while the transformation rules for spin connections relate the components of the spin connection in one coordinate system to those in another coordinate system.

Are there any specific equations or formulas for the transformation rules?

Yes, there are specific equations and formulas for the transformation rules for vielbeins and spin connections. These equations involve the use of the metric tensor, which describes the geometry of the space-time, and the Christoffel symbols, which are used to describe the curvature of the space-time. The exact form of the equations may vary depending on the specific coordinate system being used.

Why are transformation rules for vielbeins and spin connections important in general relativity?

The transformation rules for vielbeins and spin connections are important in general relativity because they allow us to describe the geometry and curvature of a space-time in different coordinate systems. This is essential for making predictions and calculations in general relativity, as different coordinate systems may be more suitable for different situations or may provide different insights into the behavior of the space-time.

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