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Archived: 07 Aug 2014, 09:45
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Notation Nabla^a in section 19.5
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yunjiangster
Joined: 21 Jul 2008, 04:37
Posts: 6
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 Notation Nabla^a in section 19.5 In the expression of the energy-momentum tensor conservation equation, we see Nabla^a. I am wondering if the superscript here means anything different from the subscript version Nabla_a, since I couldn't find a reasonable way to interpret the superscript version as an index-raised version of the subscript version via the metric g_ab.
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| 15 Aug 2008, 02:11 |
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fallingup
Joined: 13 Mar 2008, 14:06
Posts: 42
Location: Ithaca NY
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Re: Notation Nabla^a in section 19.5 yunjiangster wrote: In the expression of the energy-momentum tensor conservation equation, we see Nabla^a. I am wondering if the superscript here means anything different from the subscript version Nabla_a, since I couldn't find a reasonable way to interpret the superscript version as an index-raised version of the subscript version via the metric g_ab. The index-raised version is exactly what it is, and you don't have to interpret anything. Just calculate it.  Laura
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| 16 Sep 2008, 23:15 |
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robin
Joined: 26 Mar 2010, 04:39
Posts: 109
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Re: Notation Nabla^a in section 19.5 As an additional point, notice that the metric commutes with the covariant derivative so it doesn't matter which way round you write this. For example:
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| 06 Jul 2010, 05:53 |
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