Lie derivative and vector field notion.

In summary, the conversation discusses an approach for finding the lie derivative of a vector field and the question of whether it can be considered as a change in tensor or a tensor field property. The approach involves transforming the coordinate system and using an arbitrary connection to specify the lie derivative. The final form does not include the notion of a definite vector field for T, and it is unclear if this is correct. The conversation ends with a request for expert comments on the correctness of the approach.
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Here is an approach for lie derivative. And i would like to know how wrong is it.
Assuming lie derivative of a vector field measures change of a vector field along a vector field, take a coordinate system, xi , and the vector field fi along which Ti is being changed. I go this way, i take the vector 'T' at point xi, transform the coordinate as- xi -> xi + efi= x'i, e nearly zero. Now Ti(x) is transformed to T'i(x').
Now I subtract T'(x') with T(x).
We would do the same thing to find directional derivative of a scalar function- S( x + ef)- S(x)= S(x')-S(x)
Now back to vector T. T'j(x')= Ti(x)dx'j/dxi.
Now take Ti(x') = Ti(x) + efk[tex]\nabla[/tex]kTi. Since T(x) is a vector field. But I don't ask for a definition of connection. We use arbitrary connection and try to see if T(x') is completely specified by T(x) by requiring specification of connection [tex]\nabla[/tex].
So T'j(x')= Ti(x') - e( fk[tex]\nabla[/tex]kTi(x) - Tk(x')dfi /dxk
To first approximation.
This finally gives, considering first order in e,
T'j(x')= Ti(x) - e( fk[tex]\nabla[/tex]kTi(x) - Tk(x')[tex]\nabla[/tex]kfi)
= Ti(x) + e(lie derivative required) + e2(terms..)
As is seen here, the final form does not include the notion of a definite vector field for T. Even connection [tex]\nabla[/tex] can be removed from lie derivative for vector. I need to know if it is correct, the assumption that lie derivative can be considered as change in tensor, not necessarily a tensor field. Or is a precisely defined tensor field property already used here?
 
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  • #2
I really need to know if its correct. Its simple maths though looks long. Could someone help? Experts' comments?
 

FAQ: Lie derivative and vector field notion.

What is a Lie derivative?

The Lie derivative is a mathematical operation used in differential geometry to measure the change of a geometric object along a given direction. It is a way of calculating the rate of change of a vector field as it is "dragged" along another vector field.

How is a Lie derivative denoted?

A Lie derivative is denoted by the symbol ∇, which is read as "nabla". It is also sometimes written as LXY, where X is the vector field along which Y is being dragged.

What is the relationship between a Lie derivative and a vector field?

A Lie derivative is a way of describing the change of a vector field as it is dragged along another vector field. In other words, it is a way of measuring the rate of change of a vector field along a specific direction.

How is a vector field defined?

A vector field is a mathematical concept used in differential geometry to represent a smooth, continuous assignment of a vector to each point in a given space. It can be thought of as a function that assigns a vector to each point in a given region.

What is the significance of the Lie derivative and vector field notion in physics?

The Lie derivative and vector field notion are fundamental concepts in physics, particularly in the study of spacetime and general relativity. They are used to describe the behavior of physical quantities, such as energy and momentum, as they change in the presence of other physical quantities.

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