Questions tagged [physics]
Questions related to the application of Mathematica to problems in physics.
825
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Mathematica VectorPlot no longer displays the plot it used to, despite the code being exactly the same? [closed]
I'm trying to plot the electric field of source charges. I was working on this the other day, and the plots I had were working just as I had intended. After continuing work today, I realized that ...
3
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1
answer
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Solving 3D Nonlinear Integral Partial Differential Equation
I am trying to solve Equation number (1.2) numerically in MATHEMATICA. This equation is solved in the papers https://arxiv.org/pdf/2205.05193.pdf, https://arxiv.org/pdf/2202.13264.pdf, and https://...
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1
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How can I expand this code to track two particles instead of one?
I'm attempting to track the position of two particles by recording a .tiff file of their visual movement under a microscope. I use Mathematica to Binarize with a high enough threshold so that only ...
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2
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1
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Unable to solve the given equation
I am trying to solve the given system in terms of $r$, for which I use the following code:
...
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Finding values of constants for which 1st and 2nd order derivatives of a function vanish
I'm trying to find critical values of some constants $v_c$ and $T_c$, for which holds the equality below:
$$\bigg(\frac{\partial P}{\partial v}\bigg)\biggr\rvert_{v=v_c,\; T=T_c}=0,\quad \bigg(\frac{\...
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1
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Plot The Magnetization
I have a problem with plotting a function M(T).
The matrix is the following:
...
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Real-time interactive simulation
I would like to know how to use mathematica to make a real-time physics simulation that can be interacted with using a cursor.
As an example, consider a classical magnetic dipole in a background field,...
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Problems with plotting NIntegrate and speeding up NIntegrate
I'm trying to plot a function $E_{01}(p)=0.5^{2}(-8+6p)+\frac{1}{N}\displaystyle\sum_{\mathbf{k}}(\sqrt{A_{\mathbf{k}}^{2}-B_{\mathbf{k}}^{2}}-A_{\mathbf{k}})$
where $A_{\mathbf{k}}=0.5(8-6p(1-\frac{1}...
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Error message installing Ricci
I just started using Mathematica. With the goal of solving
a Loop integrals over a scalar gravity interaction. For the tensor calculus necessary i wanted to use, Ricci. https://sites.math.washington....
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3
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1
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How can one find the corresponding black body temperature, when trying to fit the integrated planck function (energy flux) to a value
Given a certain numerical value for the energy density flux $F$ of a star, e.g. the solar constant $s_\odot = 1362~\frac{W}{m^2}$, and a certain wavelength range corresponding to the irradiated energy ...
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Graph Convolution Network, molecule activity
I am trying to translate an example code for graph convolution network from Deep Learning for Physical Scientists: Accelerating Research with Machine Learning.
Edward O. Pyzer-Knapp et. al. They have ...
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2
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2D Projection of a 3D plot on the three walls using three different colours
I was plotting Lorenz Attractor in 3D. Now, I wanted to take three projections of it on three different planes(XY, YZ, ZX) with four different colours. I mean I want my 3D attractor in one colour and ...
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Feynman Rules in FeynCalc
I am trying to find the feynman rules with FeynCalc Package. K1 and K2 are the mésons $K^+$ and $K^-$
...
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1
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Package-X has been terminated. FeynCalc and FeynHelpers not working
I want to compute the finite parts of 1-loop integrals using FeynCalc. One of the most important package used for this is FeynHelpers (which in it uses Package-X).
But, since July 1, 2022, Package-X ...
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How to simulate hysteresis loop for a ferrimagnetic material
I am trying to modify a ferromagnetic hysteresis loop to ferrimagnetic hysteresis loop.
Below is the equation I used for ferromagnetic simulation :
Below is the code for above equation:
...
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1
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59
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How to Plot a graph with respect to time [closed]
I am new to wolfram Mathematica. Can someone please assist by showing me how I can plot “d” shown in The screenshot with respect to time, graphically?
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Feynman Two Loop Integrals
Is there any reference suitable for a beginner that you recommend for learning two loop integrals evaluation by hand ( and/or some package) that you know of?
Thank you very much.
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2
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1
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Solving 2D Coupled Nonlinear SO Coupled Equation
I am trying to solve coupled nonlinear SO coupled equations in 2D from the following two papers https://arxiv.org/pdf/2105.08849.pdf and https://arxiv.org/pdf/2109.00491.pdf. They have given an input ...
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Constructing NxN tridiagonal block diagonal matrix with N is a variable [closed]
Hi please can someone help me writing a program of generating a tridiagonal block matrix with dimension of NxN where N is a variable can be 50, 100, 200, 300...etc , Well I don't know how I'm a ...
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1
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Lyapunov exponents at a fixed point
I am trying to find the Lyapunov exponents at a fixed point as given in the paper here(page 14). The code that I have used till now is given below:
...
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1
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Calculating power series of quantum operators on kets
I am using the "Quantum" add-on package to perform some quantum mechanical calculations using SU(1,1) generators. The code that I've developed reads
...
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1
answer
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Solving logarithmic 2D Nonlinear GPE Equation
I am trying to solve the logarithmic 2D Nonlinear GPE Equation from this paper https://arxiv.org/pdf/1801.10274.pdf. But failed to get the ground state solution and vortices. I tried to solve in ...
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1
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Monte Carlo Simulation of Charged Particles in Non-Uniform Electric Field
I have a code (provided below) which simulates the motion of an ensemble of charged particles which are subjected to a complex static electric field which passes through some aperture in a metallic ...
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1
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Sticky Collisions (perfectly inelastic)
There is an awesome simulation https://mathematica.stackexchange.com/a/124926/87086 which shows N particles bouncing in a box (with elastic collisions), made by @Feyre https://mathematica....
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Fitting a sum of three lorentzian based on a dataset
as you can see below, I have developed a code that allows me to fit the present dataset via a Lorentzian. Now what I should do is to develop a sum of three Lorentzians based on this model so that this ...
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1
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Fourth order, nonlinear PDE depicting dynamics of liquid lenses
PROBLEM STATEMENT
Recently, I was trying to verify the solution of a set of thin film spreading equations given by this paper.
Where
$$p1=-(h_{1xx}+\sigma h_{2xx})$$
$$p2=-\sigma h_{2xx}-\Pi[h2-h1]$$
...
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3
votes
1
answer
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Using WhenEvent to stop N objects at a boundary
I am attempting to implement an event into my simulation which makes any moving particle in an electric field completely stop at the instant they pass some specified threshold.
I was trying to utilize ...
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1
answer
152
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Properly Updating Particle Motion in 3D Electric Field Simulation
I have a code (very bottom of post) which plots a static electric field as it passed through some metal sheet with an aperture in it.
I seek to observe the motion of some N charged particles (point ...
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1
answer
54
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3D Parametric Plotting for N Charged Particles in a Nonuniform Electric Field
I have a code (very bottom of post) which plots a static electric field as it passed through some metal sheet with an aperture in it.
I seek to observe the motion of some N charged particles (point ...
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0
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NDSolve does not go past initialisation stage when attempting to solve for Fluid System
BACKGROUND INFO
Following my attempt to solve a fluid system here (I am very much indebted to xzczd for his gracious help), I realised that a few of my equations are physically incorrect since they ...
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Simulating the Response of Charged Particles to Apertures with Inhomogeneous Electric Fields Passing through them
I have produced a simulation which allows me to observe a static electric field produced by a charged plate as it passes through some complex apertures in a different, oppositely charged metal plate.
...
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1
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Error in Attempting Moving Boundary Fluid System
Recently I was attempting to solve a moving boundary fluid system on mathematica, which I have managed to convert into a coupled PDE-ODE system based on this helpful reference over here.
The equations ...
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Implementing a 10-dimensional metric using diffgeo
I am trying to implement a 10-dimensional metric, namely a solution of type IIB supergravity equations of motion, using diffgeo by Matthew Headrick.
Physics
The metric is
$$ds_{10}^2=\sqrt{\frac{...
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1
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112
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How to create a matrix with multiple variables defining the elements?
I am a learner start using Mathematica to study quantum mechanics. In many cases, I am try to construct matrix with functions like this:
For example, let f be a function taking 4 variables x1,x2,x3,x4,...
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1
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Droplet of water-alcohol mixture spreading due to evaporation-caused surface tension gradient
I am trying to solve a coupled system of PDEs for 2 functions h[t,r] and c[t,r], with initial conditions of ...
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FEM: modelling 2D flow under periodic forcing
Despite many examples of periodic boundary conditions being presented, it remains difficult to obtain a periodic solution. Let us consider a simple example of a flow in a two-dimensional channel under ...
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0
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FunctionInterpolation with some datapoints to start with [closed]
Motivation:
I am using FunctionInterpolation[COMSOL[x]] in combination with COMSOL to search for the interpolation of my COMSOL model.
COMSOL needs a lot of time to ...
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3
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1
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Error in Metropolis-Hastings with three states?
I wanted to create a simple example of the Metropolis-Hastings algorithm as a sanity check but the check failed and the results do not line up. I have a vector of energies $\vec E=(E_1,E_2,E_3)$ and ...
3
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1
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Convergence plot of Lyapunov exponents
I am trying to reproduce the convergence plot of the four Lyapunov exponents for a string from this paper (page 12, figure 7).
The code that I have used till now to find the equations is given below:
<...
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2
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1
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1
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Finding Hamiltonian from a perturbative Action
I am given a perturbative action $$\frac{S}{\mathcal{T}}=\int dt\sum _{n=0,1} (\dot{c_n}{}^2-c_n^2 \omega _n^2)+7.11 c_0^3+35.3 c_0 c_1^2+4.66 c_0 \dot{c_0}{}^2+1.32 c_0 \dot{c_1}{}^2-7.57 \dot{c_0} ...
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3
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Neglecting higher order terms in a Lagrangian
I have a lagrangian which is modified by variable change. I want to neglect all the 4th order and higher terms in the new lagrangian. The code being used is given below:
...
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Variation with respect to inverse metric in a Lagrangian density
I am trying to vary the following Lagrangian density
with respect to the inverse metric appearing in the equation, but I am having trouble with how to write the right code in Mathematica.
I have ...
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1
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create an animation of a string
I'm trying to create an animation of motion of a physical string, it should demonstrate a "jumping rope", but I don't know what function to use, I've tried parametric plot and vector plot. I ...
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Methods of Numerically Finding Function Minimizing Functional
Say we have some functional like the following: $H = (\partial_yf(y))^2 -w(y) f(y)^2 +f(y)^4/2$. This is the functional for the Gross Pitaevskii equation. Lets say $w(y)$, the trapping potential in ...
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Error Integrate::ilim: Invalid integration variable or limit(s) in {0.1,0,1}. please help
I am making the code you can see below. I believe the error is that when I plug in values for x it also feeds back to the "dx" in the integration, how can I go around that?
...
5
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1
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291
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Poincaré Section from action
I am given a perturbative action $$\frac{S}{\mathcal{T}}=\int dt\sum _{n=0,1} (\dot{c_n}{}^2-c_n^2 \omega _n^2)+7.11 c_0^3+35.3 c_0 c_1^2+4.66 c_0 \dot{c_0}{}^2+1.32 c_0 \dot{c_1}{}^2-7.57 \dot{c_0} ...
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Gaussian 16 fchk and log file import in mathematica
I am working with Gaussian log files and fchk files imported into Mathematica and I noticed a few things.
The ExampleData in documentation for these files use Gaussian 03 output files, while the ...
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2
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233
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Stretching a mesh
Imagine I want to stretch a mesh with a 'rubberband-type' effect. That is, upon and elastic stretch from both side edges, the mesh centres simply scale as follows
where the points are seeds for ...
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Why do expressions with physical units not get simplified?
I am trying to calculate precise values for certain expressions, see the image below.
The output testZPF of the function $\Delta$Fn should be a single output. I am ...
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