Christoffel symbol and Einstein summation convention

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SUMMARY

The discussion centers on the definition and representation of Christoffel symbols, specifically the equation Γijkei=∂ej/∂xk. It is established that while the equation Γjjk=ej ⋅ ∂ej/∂xk is valid, it does not uniquely identify the Christoffel symbols due to the omission of terms where the indices differ (i ≠ j). The conversation highlights that there are n^3 connection coefficients in an n-dimensional space, emphasizing the complexity of the relationship between the indices and the basis vectors.

PREREQUISITES
  • Understanding of Christoffel symbols in differential geometry
  • Familiarity with the Einstein summation convention
  • Knowledge of basis vectors and their components
  • Basic concepts of connection coefficients in Riemannian geometry
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  • Study the properties of Christoffel symbols in Riemannian geometry
  • Learn about the Einstein summation convention and its applications
  • Explore the derivation of connection coefficients in n-dimensional spaces
  • Investigate torsion-free connections and their implications in geometry
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Students and researchers in mathematics and physics, particularly those studying differential geometry, general relativity, or tensor calculus.

Mathematicsresear
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Homework Statement


I know that by definition Γijkei=∂ej/∂xk implies that Γmjk=em ⋅ ∂ej/∂xk (e are basis vectors, xk is component of basis vector). Can I write it in the following form? Γjjk=ej ⋅ ∂ej/∂xk Why or why not?

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The Attempt at a Solution

 
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While what you wrote would be valid, it would not uniquely identify the Christoffel symbols (it completely ignores the symbols ##\Gamma^i_{jk}## for which ##i \neq j## and sums over those where ##j = i##. Your equation has one free index and therefore represents n equations in an n-dimensional space. However, there are ##n^3## connection coefficients (##n^2(n+1)/2## if you require your connection to be torsion free).

Mathematicsresear said:
xk is component of basis vector
No it is not, it is a coordinate.
 

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