bshoshany
commented
1 year ago Thanks so much for reporting this issue! The calculation appears to be stuck in the simplification phase. Since the Riemann tensor for this metric is extremely complicated, Mathematica is unable to finish simplifying the result. A frequently-requested feature for this package is to disable automatic simplification of results, for cases like this. I am currently working on the new release of OGRe, v2.0.0, which will include that feature, and will even allow you to define a custom simplification function (which can be, for example, Simplify, Refine, and so on). In addition, it will have many other new features and bug fixes. Meanwhile, as a temporary fix, if you open OGRe.m and replace all 3 instances of FullSimplify with Simplify, your notebook will run successfully.
First of all, thank you very much for all of your efforts in developing this easy-to-use and powerful tool.
I'm working with a specific metric, the one proposed by Hadad and Zakharov in the following article: https://www.sciencedirect.com/science/article/pii/S0393044014000266#s000020. I can get the various useful tensors (Riemann, Ricci, Weyl etc.) but when I tried to compute the Kretschmann scalar things get complicated.
I use the method presented in your article to contract the Riemann tensor by itself. The code seems to run as the progress bars advance, but at a final stage nothing appear. It's as if the code fall into an infinite loop. The strange thing is that there was no problem when trying to calculate this scalar for common metrics (Schwarschild, FLRW).
The notebook can be found here: https://github.com/benoit-gay/Hadad-Zakharov/
I don't know if this problem can be solved, but I'd like to take the liberty of throwing this bottle into the sea.
Thank you very much for your attention and your help.
B.