search

rtoy / maxima

A Clone of Maxima's repo
Other
0 stars 0 forks source link

Ctensor perdefined spacetimes have incorrect coframes #1178

Open rtoy opened 2 weeks ago

rtoy commented 2 weeks ago

Imported from SourceForge on 2024-07-04 01:48:44 Created by richardgobeli on 2022-05-24 23:43:14 Original: https://sourceforge.net/p/maxima/bugs/3980

When using frames the predefined coframes are defined as mixed tensors and the ctensor program assumes they are lowered tensors. To make the predefine coframes for exteriorschwarzschild, interiorschwarzschild, isotropicschwarzschild, and kerr_newman correct, the fri should equal lfg . fri. This will make the coframe a lowered tensor. The coframe for cartesian4d is correct, because it has +4 signature so lfg is all positive and the fri is not changed by lfg. These coframe tensors came from DOE ctensor program where the coframe was defined as mixed tensor.

rtoy commented 2 weeks ago

Imported from SourceForge on 2024-07-04 01:48:45 Created by vttoth on 2022-05-25 06:35:49 Original: https://sourceforge.net/p/maxima/bugs/3980/#1721