Sept 15, 2008
Quotations from Evans' writings in
Subject: Further Misrepresentation by Bruhn Date: Sun, 14 Sep 2008 11:41:24 EDT
Bruhn has attempted further misrepresentation of Cartan geometry by attempting once more to assert that
D ^ R = 0 is valid for all connections, when it is valid only for the symmetric conenction.
Indeed!!! Evans is confirming here once more his total misunderstanding of
Cartan's differential geometry: As can be seen from the text books, e.g. the books
[1, p.93] and [2, p.489] by S.M. Carroll for general torsion we have
D Ù Ta :=
d Ù Ta +
ωab Ù Tb
=
Rab Ù qb ,
(1st Bianchi identity)
D Ù Rab :=
d Ù Rab +
ωac Ù Rcb
−
ωcb Ù Rac
= 0 .
(2nd Bianchi identity)
So as usual he attempts to misrepresent my rebuttal, which is a quotation of Carroll, page 81 of his online notes following Carroll’s eq. (3.88). In respect of the second Bianchi identity Carroll writes “Notice that for a general connection there would be additional terms involving the torsion tensor”. These torsion terms are given by the correct derivative identity of ECE theory:
D ^ (D ^ T) := D ^ (R ^ q)
As I wrote: This is a trivial (and therefore useless) implication of the 1st Bianchi
identity, and has nothing to do with the 2nd Bianchi identity.
In one of his latest misrepresentations, Bruhn asserts that the quotation at the foot of Carroll, page 91
refers to the Bianchi identity. It does NOT, it refers to the tetrad postulate. Earlier Bruhn had attempted
to misrepresent the tetrad postulate itself. Now he accepts it.
Carroll's remark in his Lecture Notes Chap.3, Eq.(3.141)
is preliminary to his calculations on the subsequent pages too
where the 2nd Bianchi identity Eq.(3.141) is derived for general torsion.
And Carroll writes there in addition:
Further confirmation can be found by
independent
calculation or in the text books by S.M. Carroll [2, p.488 ff.] or by
F.W. Hehl and Y.N. Obukhov [3, p.208, eq.(C.1.69)].
''The first of these is the generalization of
Rρ[σμν] = 0
while the second is the Bianchi identity
Ñ[λ|Rσ|μν] = 0.
(Sometimes both equations are called Bianchi identities.)''
Bruhn states that he is trying to force me into debate, so I will not debate,
merely correct. The more this goes on, the more the evidence piles up
against him, and the more he is ignored.
That's your problem, Myron, not mine.
Your corrections are welcome. However, since your ''corrections'' are always going
astray:
Some proposals: What about the
Poincaré Lemma
d Ù d Ù ω = 0 ?
Or your
3-D Îabc tensor in 4D tensor calculus?
Or what about your
dualization of the 1st Bianchi?
Or ... or ...
Before writing once - think TWICE!
Now he has been reduced to outright dishonesty and misquotation, thus bringing TU Darmstadt into disrepute. He is out of touch with reality if he seriously expects me to debate him now. It takes me a few minutes only to correct him, in order to further build evidence against him, in public.
Civil List Scientist
Wishful thinking!
[1] S.M. Carroll, Lecture Notes on General Relativity,
[2] S.M. Carroll, Spacetime and Geometry,
[3] F.W. Hehl and Y.N. Obukhov, Foundations of Classical Electrodynamics -
Charge, Flux, and Metric,
References
http://xxx.lanl.gov/PS_cache/gr-qc/pdf/9712/9712019v1.pdf
Addison Wesley 2004, ISBN 0-8053-8732-3
Birkhäuser 2003, ISBN 0-8176-4222-6
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