2.9.3 Can you answer these questions?

2.9.3.1 Equation of Motion: Perturb Scalar Field and flat FLRW Metric (xAct)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233105

Is there a way to get the equations of motion (eom) of a scalar field from a Lagrangian in a perturbed FLRW metric? I want to perturb the field as well as the metric to 1st order. What I did so far:

asked by kalle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68748 1 vote

2.9.3.2 Is there any way to change the box-formatting behavior thoroughly?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233100

Background The box-formmating behavior is affected by the downvalues of the symbol MakeBoxes. But the formatting behavior is not exactly ...

asked by asd1dsa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72876 2 votes

2.9.3.3 How to get colors at points in Graphics3D?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233287

To get the color at a 2D point in Graphics you can Rasterize it and look up the pixel value, but not for ...

asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 2 votes