Undergrad Finding Riemann Components: Packages & Solutions

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The discussion centers on calculating Riemann tensor components in hypothetical spacetimes using Mathematica and Python. The user seeks recommendations for efficient packages due to time constraints and mentions OGRE as the best Mathematica package found. Another participant suggests using einsteinpy with Jupyter for general tensor analysis in Python. The user successfully installs OGRE and confirms it can compute the necessary components, expressing interest in exploring Python options later. The conversation highlights the utility of specific software packages for tensor calculations in general relativity.
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I'm working on a problem involving some hypothetical spacetimes (i.e. no tables/data-sheets available) and need to calculate a bunch of ##R_{\mu \nu \rho \sigma}## and ##R_{\mu \nu}## values, as well as ##R##. The metrics contain some arbitrary functions ##f(x^i)## of the spatial co-ordinates only. There's a little bit of urgency so I can't afford really to spend a great deal of time exploring which packages are best for this task; I hoped that somebody who feels confident with this could advise? Thanks!
 
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I just finally started to learn Python, and for computer algebra in GR (I guess it can easily be used for other general tensor-analysis work too) I like einsteinpy. Together with jupyter as the frontend it's very nice to work with:

https://einsteinpy.org/
 
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Dale said:
I use Mathematica for all things math-related. The best Mathematica package I have found is OGRE

https://arxiv.org/abs/2109.04193
Thank you, this looks promising. I noticed in the documentation that it seems to allow you to specify the co-ordinate dependencies of scalar fields, which is one thing I need.

Please allow me some time to install Mathematica and try to run the package!
 
I just wrote my own mathematica file to do it for me. Mainly to double check exam answers before putting the exam to the students. It is not that extensive computations after all.
 
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Dale said:
I use Mathematica for all things math-related. The best Mathematica package I have found is OGRE

https://arxiv.org/abs/2109.04193
It's now working, I can find all of the components.
When I have more time I might experiment with a Python package.

Will shout if problems arise! :oldwink:
 
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In an inertial frame of reference (IFR), there are two fixed points, A and B, which share an entangled state $$ \frac{1}{\sqrt{2}}(|0>_A|1>_B+|1>_A|0>_B) $$ At point A, a measurement is made. The state then collapses to $$ |a>_A|b>_B, \{a,b\}=\{0,1\} $$ We assume that A has the state ##|a>_A## and B has ##|b>_B## simultaneously, i.e., when their synchronized clocks both read time T However, in other inertial frames, due to the relativity of simultaneity, the moment when B has ##|b>_B##...

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