question about lorentz_g contract with sy_anti tensor
Hi all, I wonder is there a way or method to simplify the expression with a sy_anti tensor contracted with a lorent_g to 0? Please have a look at the following code, I expect ret is 0, and the output looks like “A~b~a.c~c”, it is actually 0 due to the sy_anti, but I wonder, is there a way or a method to simplify those expression directly to 0? Thanks very much! using namespace GiNaC; using namespace std; int main(int argc, char** argv) { symbol a("a"), b("b"), c("c"), d("d"), A("A"); symbol D("D"); varidx ia(a,D), ib(b,D), ic(c,D), id(d,D); auto ret = indexed(A, sy_anti(0,1,2,3), ia,ib,ic,id) * lorentz_g(ic.toggle_variance(), id.toggle_variance()); cout << simplify_indexed(ret) << endl; return 0; } Best regards! Feng
On Thu, 23 May 2019 00:57:21 +0000, Feng Feng <F.Feng@outlook.com> said:
FF> Hi all, I wonder is there a way or method to simplify the FF> expression with a sy_anti tensor contracted with a lorent_g to FF> 0? You will get 0 if you will use auto ret = indexed(A, sy_anti(0,1,2,3), ia,ib,ic,id) * lorentz_g(ic, id.toggle_variance()); Anti-symmetry is not applied to varidx with different variance. -- Vladimir V. Kisil http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://goo.gl/EaG2Vu Software: Geometry of cycles http://moebinv.sourceforge.net/ FF> Please have a look at the following code, I expect ret is 0, and FF> the output looks like “A~b~a.c~c”, it is actually FF> 0 due to the sy_anti, but I wonder, is there a way or a method FF> to simplify those expression directly to 0? FF> Thanks very much! FF> using namespace GiNaC; FF> using namespace std; FF> int main(int argc, char** argv) { FF> symbol a("a"), b("b"), c("c"), d("d"), A("A"); FF> symbol D("D"); FF> varidx ia(a,D), ib(b,D), ic(c,D), id(d,D); FF> auto ret = indexed(A, sy_anti(0,1,2,3), ia,ib,ic,id) * FF> lorentz_g(ic.toggle_variance(), id.toggle_variance()); FF> cout << simplify_indexed(ret) << endl; FF> return 0; FF> } FF> Best regards! FF> Feng
participants (2)
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Feng Feng
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Vladimir V. Kisil