Relativistic Invariance Part Two

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SUMMARY

The d'Alembertian operator, denoted as |_|^2, is confirmed to be a Lorentz invariant operator. To demonstrate this, one should show that it is a scalar quantity, achieved by proving it as a contraction of a first-rank tensor with itself. Utilizing the Minkowski metric tensor to raise the index of one of the partial derivatives simplifies the proof. This approach is more effective than merely multiplying the Lorentz transformation matrix by the second partial derivatives.

PREREQUISITES
  • Understanding of the d'Alembertian operator in four-dimensional spacetime
  • Familiarity with Lorentz transformations and their properties
  • Knowledge of tensor calculus, particularly first-rank tensors
  • Proficiency in using the Minkowski metric tensor
NEXT STEPS
  • Study the properties of the d'Alembertian operator in quantum field theory
  • Learn about Lorentz invariance and its implications in physics
  • Explore tensor contraction techniques and their applications
  • Investigate the role of the Minkowski metric tensor in relativistic physics
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The discussion is beneficial for physicists, particularly those specializing in theoretical physics, quantum field theory, and anyone interested in the mathematical foundations of relativity.

Ed Quanta
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I am asked to prove that the d'Alembertian operator (the 4 dimensional Laplacian operator) |_|^2 is a lorentz invariant operator. Do I just multiply the Lorentz transformation matrix by the second partial derivatives with respect to four space?
 
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Originally posted by Ed Quanta
I am asked to prove that the d'Alembertian operator (the 4 dimensional Laplacian operator) |_|^2 is a lorentz invariant operator. Do I just multiply the Lorentz transformation matrix by the second partial derivatives with respect to four space?
I suppose you could do that. But I would just show that it is a scalar. Show that it is a contraction of a 1st rank tensor with itself. Use the Minkowski metric tensor to raise the index of one of the partial derivatives and it should be obvious.
 
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