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

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5
votes
3answers
119 views

Finding the conditions for degenerate solutions to a cubic equation

I have a cubic equation (corresponding to the band structure of a physical system) given by w in the code below. ...
30
votes
3answers
688 views

A better “VisibleSpectrum” function?

Since ColorData["VisibleSpectrum"] is wrong, I would like to have a more accurate function to use. Can this information be extracted from Mathematica itself?
9
votes
1answer
698 views

NDSolve::ndcf: Repeated convergence test failure. How to solve?

I am trying to simulate a system of $n$ pendulums with some friction in Mathematica 9. This is the code I am using: ...
3
votes
1answer
69 views

Eigenvalues function not producing expected results?

I'm running into a strange issue when trying to compute eigenvalues of a 2x2 matrix for graphene. If I "manually diagonalise" by multiplying the two off-diagonal terms together and taking the square ...
0
votes
1answer
79 views

FullSimplify not giving me a physically useful answer for Mott scattering

I am using Mathematica to find the cross-section for Mott scattering over an extended target. I evaluated ...
25
votes
3answers
2k views

Is there something like DensityPlot3D to visualize atomic orbitals?

I'm visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something ...
20
votes
3answers
1k views

Convert spectral distribution to RGB color

Presume I have a spectrum as a function of wavelength (an example being the blackbody spectrum): I want to convert that to a single RGB color to display on-screen, i.e. the "color" of that object ...
18
votes
3answers
607 views

How to plot an emission spectrum?

If I have a list of data with various wavelengths in nanometers, how would I plot them on a graph so it looks like this: So far I have managed to plot a spectrum in ...
1
vote
1answer
159 views

Modeling a stellar atmosphere

I'm trying to model a stellar atmosphere using Mathematica. Basically I'm working in a physical and chemical model which combined should give me a profile of the chemical abundance in the atmosphere. ...
11
votes
2answers
269 views

Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra

I am trying to work on spin chains in Mathematica. That is, N spin-1/2 on a one-dimensional lattice with periodic boundary condition (N+1=1). I need therefore the SU2 spin algebra $S_z, S_+, S_-$ with ...
1
vote
1answer
59 views
11
votes
3answers
221 views

Mimic a procedural, recursive clustering algorithm for site percolation using functional programming

Sorry in advance for my logorrhea: I just want to make sure all of the information is here. Context and Question I am investigating site percolation on a square lattice. I have a working, ...
2
votes
2answers
162 views

Solving coupled first-order autonomous differential equations

I am trying to run a simulation of a circuit to observe chaotic behavior, and have obtained a set of differential equations from an analysis of the circuit. I thought perhaps I could produce a plot ...
8
votes
3answers
402 views

Biot-Savart Law/Magnetostatics Solution

I am working on solving the Biot-Savart Law equation for the magnetic field around a charged ring of uniform current density. The expression that Mathematica gives is rather nasty, as expected. Notice ...
0
votes
0answers
46 views

how to make one plot for each line of a table of 127 datas (127 plots) , or one plot with 127 curves onto it?

Good evening, I encounter a difficult problem. I have 127 lines of data, with for each line, 9 columns. I imported from a txt file : ...
0
votes
1answer
87 views

Animating a parametric plot

I am attempting to animate my parametric plot, but am having difficulties. I tried simply wrapping the plot code with an Animate[expression,{t,0,5}], but that ...
7
votes
2answers
310 views

Defining quantum-mechanical Bra and Ket operations

I have the following ket in the Fock basis: $\vert3, 0 ,1\rangle$, where each entry defines the number of photons in a particular mode and can take any one of the following numbers: 0, 1, 2, 3. As a ...
4
votes
0answers
94 views

Synchrotron Radiation and ListDensityPlot

I'm trying to reproduce this plots: For this task i'm following this blog entry: Synchrotron radiation As you can see there, the task is to make a DensityPlot of a vector field essentially. This ...
1
vote
0answers
93 views

How can I improve the solution of my PDE?

I want to improve the last code to find a better solution for umi. For now I'm using only MaxStepFraction. Also, when I put no ...
19
votes
2answers
2k views

Animation of double pendulum

Sadly, I am a completely newbie. I am studying Physics and in our theoretical physics class we got the task to solve the double pendulum using Mathematica. We just got the program, but no introduction ...
1
vote
1answer
81 views

Diff eqs can be solved?

I'm trying to solve a pair of coupled differential equations, but am having trouble making DSolve evaluate my equations. ...
1
vote
2answers
82 views

Plot ParametricNDSolve

I am trying to plot the probability of a molecule being in a certain state via the numerical solution of the Schrödinger's equation of molecule in an oscillating electric field (in a rotating system). ...
8
votes
3answers
951 views

How to manipulate gauge theory in Mathematica?

I want to know if there is a way of typing into Mathematica an expression like the following, $$\epsilon^{\mu \nu \lambda} f^{abc} A^a_\mu A^b_\nu A^c_\lambda + g\epsilon^{\mu \nu \lambda} A^a_\mu ...
2
votes
1answer
100 views

Fundamental question about capabilities of Mathematica to represent abstract mathematics [closed]

I have an fundamental question about what Mathematica can and cannot do. I have a book which presents a certain physical theory in an axiomatic manner. The axioms make heavy use of mathematics. Some ...
3
votes
1answer
468 views

Animated Wave Propagation using Fourier & InverseFourier

This is a continuation off of previous help on the first part of my project: fourier issue arising from input miscommunication Now I want to go one step further in the current code. Here's the code ...
0
votes
0answers
22 views

How to solve coupled first-order ODE with vectors?

m * v'[t] = q * (E + v x B) using the following: B = (0,0,B0), E=(Eperp,0,Ez). How would I find the general solution of ...
1
vote
0answers
40 views

Tracking solutions over a Brillouin zone

Thanks to @bbgodfrey I have a function that finds the two solutions to a set of equations bounded by a hexagonal region (corresponding to the Brillouin zone). It takes the angle ...
0
votes
0answers
71 views

Difficulty solving an equation involving a couple of different powers

I have this semi-complicated equation to which I want to find an analytical solution for $\epsilon$. The equation is a s following: $$a^2 (2 b k \epsilon \sqrt{1 - \epsilon^2/b^2} - 2 c k ...
7
votes
2answers
254 views

Integrating a function over a surface integral

From a first principles bandstructure calculation I get an energy scalar field in three dimensions $E(x,y,z)$. It's now easy to plot a constant energy (contour)-surface for dedicated values ...
0
votes
0answers
33 views

How to implement time dependence in the DoFun package?

DoFun is a very usefull mathematica package that helps to write Dyson-Schwinger and FRG flow equations when these are to complex to write down by hand. You can download it here and read it's manual ...
0
votes
1answer
85 views

Eigen energies of 2D time independent Schrödinger equation

Firstly, I am aware that a similar question of this type was asked, but it was not helpful as it was only one dimensional (so please don't mark my question as a duplicate) The trouble I am having is ...
0
votes
0answers
41 views

Controlling scaling of multiple vector fields in VectorPlot3D

I'm trying to plot the electric and magnetic fields of a relativistically moving electric charge using VectorPlot3D, and apply "Manipulate" to change the velocity. The code I'm using is as follows: ...
0
votes
1answer
66 views

Problem simulating a wave on a string by solving the wave equation as a difference equation.

This is a question I posted earlier however the purpose of what I'm doing is going to be expounded much more clearly. ...
1
vote
1answer
43 views

Implicit region is not “valid” in ParamatricNDSolveValue function?

I am trying to solve a geometric problem with relation to my Schrodinger equation and its boundaries. Here is my code: ...
0
votes
0answers
133 views

Plotting: Magnetic field lines

I have data which I am trying to plot as 3D field lines. I need to plot points at coordinates i, j and ...
1
vote
0answers
34 views

How to evaluate Poisson Bracket? [closed]

I'am new in Mathematica so please don't yell at me. I want to define Poisson Bracket in Mathematica 9 and evaluate it for two functions,but it didn't worked. Could you help me please? ...
0
votes
1answer
88 views

How to plot and visualize a single linear vector in 3D? [closed]

I have a vector (in physic) designated as F1=250cos(60)i+250cos(60)j+250cos(45)k, and i would like to see it in a 3D graphic with the axis centered at the origin, after what i would include other ...
1
vote
1answer
81 views

Particle motion with discrete values for the potential

Sorry if the question seems trivial, but I am new to physical simulations in Mathematica. I have a numerical estimation of an electric potential $V(x)$ in 3D, to be more precise I have a matrix ...
0
votes
0answers
92 views

How to filter my signal?

As you can see, my signal is superimposed by an other sinus which has a slightly longer frequency. I would like to filter this out. I think I can do the filtering process, but there is one step that I ...
1
vote
1answer
201 views

NSolve fails to solve a nonlinear equation

Mathematica can not solve this: g = 9.82; ω = 0.5; h = 5; y0 = 1; v = 0; τ = 0; NSolve[h + v t - (g t^2)/2 == y0 Sin[ω t], t]; The error code is: ...
36
votes
6answers
2k views

ColorData[“VisibleSpectrum”] is wrong?

I am trying to visualize the visible spectrum using the built-in ColorData["VisibleSpectrum"] function which "colors based on light wavelength in nanometers". But I ...
0
votes
0answers
42 views

Failure to evaluate functions of derivatives of Theta functions

I define a variant of the EllipticTheta function (multiplied by a constant factor) : ...
1
vote
1answer
45 views

Variables within functions within DSolve

Hi I am just beginning to learn Mathematica and this is my first time I have been exposed to any type of coding. I am encountering a problem in a basic physics problem. For example we are always ...
3
votes
0answers
145 views

Numerical integration: complicated 2D integral seems to be poorly estimated

In the course of some physics research I've been working on, a very annoying integral has appeared that I'm having difficulty evaluating numerically. Any help you could offer would be greatly ...
0
votes
0answers
30 views

Can't Load .rst file

I've been working with the FeynRules 2.1 package in Mathematica 10. If I download the MC4BSM_2012 FeynRules files and run the Mathematica Notebook I've got no problem in Ubuntu (A lot of warnings ...
0
votes
1answer
75 views

How can I use manipulate on multiple lists within a function?

So I have my N-Body Problem set up like so, and I can plot it in ListPointPlot3D, but I cannot figure out how to stick this into a manipulate function. ...
4
votes
2answers
217 views

Embedded Graphics: General Relativity

Is there a way to make the following graph with two dimples? Like the central indent and another indent to the side to simulate a central mass like the sun and another smaller mass like the Earth in ...
2
votes
0answers
136 views

How to control pedestrians to enter the simulation region with random functions?

I am working on simulating crowds of a cross-typed region, given that pedestrians entering from 4 gates of north, east, west and south, ...
2
votes
0answers
97 views

Position from 3 dimensional acceleration data? [closed]

Per a previous post on Mathematica StackExchange here I'm trying to utilize 3-axis accelerometer data to determine approximate 3D position. I wanted to start with a simple case. To this end I've ...
5
votes
2answers
178 views

Multidimensional integral to compute the end-to-end distribution of a FENE ideal chain

How do I evaluate the mean end-to-end squared distance of a FENE ideal chain at fixed inverse temperature $\beta$ in the canonical ensemble? This quantity is defined as the mean value ...