# Questions tagged [physics]

Questions related to the application of Mathematica to problems in physics.

432 questions
32 views

### Error caused by ThreeJSymbol

I do not understand what causes non-physical answer in my code although I have read about the error. I am also getting the following error, how could I fix the example error: "CompiledFunction::cfte:...
173 views

### How to represent $2n \times 2n$ Dirac matrices in terms of Pauli matrices in block matrix format?

I am interested in building matrices out of smaller matrices, do calculations, and express the results in a block matrix form, in terms of the smaller matrices. For example, say I define the ...
52 views

### Create an array of independent variables of variable size, all dependent upon the same dependent variable

I have an array of variables that I've constructed, that all depend on time s ...
46 views

### How can I calculate all of the points of my functional at once and export the results to a file?

I have the following functional, it depends of n, m and U, so I want to automatize the calculations for all the regimes and be able to export it in a way I can copy and the past the values easily. <...
48 views

### Add more than one condition to my equation

I have the following code to solve for a bunch of n, m e U, but I need different conditions for n=0 and m=n, already explicit in my code, but I don't know how to make it work. I know I have to make it ...
311 views

### Why do my attempts to fit Planck's law fail?

I have some data and want to fit it to Planck's law for black body radiation. The problem is that Mathematica does not give me the correct coefficients. When I evaluate ...
111 views

### Raising, lowering and number operators for Dirac notation

Starting from this very interesting post Defining quantum-mechanical Bra and Ket operations, i would like to implement raising, lowering and number operators, taking into account that they might be ...
217 views

### I want to visualize this 3D like DensityPlot3D (About Diffraction of light)

Here is a code modeling the diffraction of light. I made this because I want simulate the diffraction of light and visualize the light's density. It's Fresnel diffraction, and I want to see the ...
363 views

### Ball bouncing against a wall

A ball is thrown towards a vertical wall. The ball is initially located a distance xf from the wall, a height y0 above the ground, and is released with initial velocity v0 at an angle theta to the ...
838 views

### Two bouncing balls in 1 dimension, issues with two different methods?

I'm trying to simulate 2 balls with the same mass and diameter bouncing one on top of another under gravity, see the illustration below (not ideal, but this is the best result I've got so far, the ...
113 views

### A simple implementation of higher-spin calculus (explanation given)?

I'm a physicist studying higher-spin theory. In my research, we work with fully symmetric tensors using a notation which is implicit both in the dimension of space and the order of the tensor, i.e. an ...
126 views

### Showing trajectory of a dynamics on the unit ball

I have a unit ball and a vector with r0x, r0y and r0z ,the x,y,z components at initial time which evolves to r2x, r2y and r2z as function of time. I want to show the trajectory as in the attached ...