From 49f6c042f4b705148f7d3e3eb6ccbf840ca1ebd8 Mon Sep 17 00:00:00 2001 From: "Vladimir V. Kisil" Date: Thu, 24 Dec 2015 13:18:59 +0000 Subject: [PATCH 1/2] Clarification on symmetries of metric of clifford object. The metric of a clifford object may be non-symmetric. Even if a metric is defined by a symmetric tensor, clifford object may not be aware of the symmetry and it needs to be explicitly declared. Signed-off-by: Vladimir V. Kisil --- doc/tutorial/ginac.texi | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/doc/tutorial/ginac.texi b/doc/tutorial/ginac.texi index 2677237..d58bc96 100644 --- a/doc/tutorial/ginac.texi +++ b/doc/tutorial/ginac.texi @@ -3337,6 +3337,15 @@ Note that the call @code{clifford_unit(mu, minkmetric())} creates something very close to @code{dirac_gamma(mu)}, although @code{dirac_gamma} have more efficient simplification mechanism. @cindex @code{get_metric()} + Also, the object created by @code{clifford_unit(mu, minkmetric())} is +not aware about the symmetry of its metric, see the start of the pevious +paragraph. A more accurate analog of 'dirac_gamma(mu)' shall be +specifies as follows: + +@example + clifford_unit(mu, indexed(minkmetric(),sy_symm(),varidx(symbol("i"),4),varidx(symbol("j"),4))); +@end example + The method @code{clifford::get_metric()} returns a metric defining this Clifford number. -- 2.6.4