Recent content by Nikos

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    Variational methods on Lagrangians (D'Inverno Chapter 11) - continued

    Hi TerryW! Thank you for your response! I'll try it and I'll post here soon my conclusions! Thank you again!
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    Variational methods on Lagrangians (D'Inverno Chapter 11) - continued

    Hello again! I have some problem with the variation of the legrangian that contains Kretschmann scalar. I=\int{{{(-g)}^{1/2}}{{R}^{abcd}}{{R}_{abcd}}d\Omega } I start as usually, but with a trick making use of curvature tensor symmetries...
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    Variational methods on Lagrangians (D'Inverno Chapter 11) - continued

    TerryW thank you so much for your answer! As you've spotted: {{\mathfrak{g}}_{ab}} is not defined by d'inverno as the inverse of {{\mathfrak{g}}^{ab}}={{(-g)}^{1/2}}{{g}^{ab}}, but as {{\mathfrak{g}}_{ab}}={{(-g)}^{1/2}}{{g}_{ab}}. Thank you again!
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    Variational methods on Lagrangians (D'Inverno Chapter 11) - continued

    [SIZE="3"]I use the notation {{\bar{g}}_{ab}}={{(-g)}^{1/2}}{{g}_{ab}} and {{\bar{g}}^{ab}}={{(-g)}^{-1/2}}{{g}^{ab}} So, {{\bar{g}}^{ab}}{{\bar{g}}_{bc}}=\delta _{c}^{a}\Rightarrow \delta {{\bar{g}}^{ab}}{{\bar{g}}_{bc}}+{{\bar{g}}^{ab}} \delta{{\bar{g}}_{bc}}=0 \delta...
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    Books for Quantum field theory?

    Hi,there! I want to study Quantum Field Theory but I don't know what book to use! I have a rather good background in quantum mechanics and electrodynamics, and I probably can gain access on the following books: Brown L.S. : "Quantum Field Theory" Peskin and Schroeder : "Introduction to Quantum...
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    How Do Killing Vectors Affect Geodesic Deviation?

    Can someone give some further help about the http://www.photodump.com/direct/Bbking22/hyperrelation.jpg , and tell me if that is the right way for the http://www.photodump.com/direct/Bbking22/departurefromgeodesity.jpg
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    How Do Killing Vectors Affect Geodesic Deviation?

    Thank you guys for your time . George thank you very much for the help and the nice derivation of the relation! Here is my answear for the previous relation http://www.photodump.com/direct/Bbking22/hyperrelation.jpg . I would like you to check it out and tell me if you agree.
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    How Do Killing Vectors Affect Geodesic Deviation?

    Here is a piece http://www.photodump.com/direct/Bbking22/departurefromgeodesity.jpg from "The large scale structure of spacetime" and there is noway for me to reproduce the relation for departure from geodesity and the previous relation :cry: . Is there any idea about the right process for the...
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    Charged Scalar Field Lagrangian Problem: Hawking, Ellis

    Hi,there! Here is the lagrangian for a charged scalar field http://www.photodump.com/direct/Bbking22/P-meson-Lagrangian.jpg as it can be found in “the large scale structure of space-time” Hawking, Ellis on page 68. It seem’s that I have problem varying Aa on the lagrangian because I get...
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