Questions tagged [computational-physics]
The bridge between theoretical and experimental physics which utilizes numerical analysis, specifically through the use of software, to solve problems in physics. This tag is NOT intended for use in solving problems on paper. Please note that details of writing and/or debugging code is OFF-TOPIC and should be asked at either Computational Science, Code Review or Stack Overflow.
1,903 questions
0votes
0answers
20views
How to numerically calculate laser beam quality (like β-factor, M2-factor...) fast and accurate? [closed]
ray tracing does not account for diffraction. angular spectrum propagation is too computationally expensive. Is there an algorithm that considers both diffraction and aberrations without being too ...
- 1
-1votes
0answers
45views
Why does the Hamiltonian of RK4 and leapfrog method differ so much in 3-body problem? Chaotic orbit peaks? Periodic orbit? [closed]
I have been trying to simulate the 3-body problem in python with different numerical methods (for different dt size and chaotic vs. periodic configurations) and then plotting it too compare them but ...
5votes
0answers
43views
Diagonalizing a permutation-invariant operator
Consider a system of $L$ qubits and an operator, $\mathcal{O}$, acting on the system. Every matrix element of this operator is nonzero in the computational basis, so there aren't any obvious conserved ...
- 911
13votes
1answer
336views
Physical Description of a Coin. Equations and constraints
I've been trying to describe the behaviour of a coin that can roll, spin and fall with Lagrangian Mechanics. The coin can roll without slipping with it's only "knowledge" of the floor being ...
- 1,821
2votes
1answer
81views
Help with approaching a hyperbolic PDE (QED)
This is my first question here, so I'd like to apologize in advance if there's too little, or too much information and for my general lack of "etiquette". I am in need of help with choosing ...
- 21
0votes
2answers
96views
Does gravitational time dilation imply that information is processed slower in stronger gravitational fields?
According to general relativity, time runs slower in stronger gravitational fields. From the perspective of a distant observer, a clock on the surface of a neutron star ticks more slowly than one in ...
- 314
2votes
0answers
67views
Renormalization by FeynCalc [closed]
It takes me so many time renormalizing Yukawa theory $$\mathcal{L}_{\text{Yukawa}} = \frac{1}{2}(\partial_\mu \phi)^2 - \frac{1}{2}m_\phi^2 \phi^2 + \bar{\psi}(i \not{\partial} - m_\psi)\psi + g \bar{\...
- 378
1vote
0answers
32views
When subsonic Fanno flow reaches Mach 1 - what then?
tdlr: in subsonic Fanno flow, At some point I reach Ma=1 at the exit. What happens when I then (magically) increase the length of the pipe? Will the very end stay at Ma=1 and the Mach number at the ...
- 598
1vote
1answer
100views
Assistance on numeric solution to the Grad-Shafranov equation using finite solution
I am currently trying to find a numerical solution to the Grad-Shafranov equation. I am currently using a sort of "toy problem", in which I set the flux surface to be square shaped and zero. ...
2votes
1answer
77views
M-R curves using Polytropic equation of state unexpected behavior [closed]
I'm trying to solve Tolman-Oppenheimer-Volkoff (TOV) equations in the original form $\{p^\prime,m^\prime\}$, using Mathematica, but I'm having some trouble getting the M-R plots since they seem to ...
0votes
0answers
35views
How to Calculate Ground State Scaling Dimension of a Finite Critical System Which is Conformally Invariant?
Suppose I have a 1D finite chain of a critical system (e.g., the quantum Potts model or Ising model). By introducing a conformally invariant boundary condition to the system, specific primary fields ...
0votes
0answers
47views
What does a typical spectral density function $J(\omega)$ look like for a solar photon bath, and internal vibrational phonon bath?
I am currently creating a simulation to simulate different systems of light absorbing molecules that are coupling to a photon bath (sun) and a phonon bath (internal vibrations). I have picked a ...
- 21
3votes
1answer
250views
Hydrogen atom equation with different boundary conditions
Recently, in a course on computational physics, I've been asked to solve the 3D time-independent Schrödinger equation with Coulomb potential: $$ \left(-\frac{\hbar}{2\mu}\nabla^2 - \frac{e^2}{4\pi\...
4votes
1answer
199views
References for Numerical Solutions of the Feynman Path Integral
I am looking for references that discuss numerical approaches to evaluating the Feynman path integral. Specifically, I would like references (books, papers, or reviews) that cover: Discretization ...
0votes
1answer
63views
Double pendulum, Poincaré surface
I'm experiencing some issues in computing the Poincaré surface in python. I'm following this post along with the Hamilton equations given in it (which are the same as the post mentions as a reference)....
- 871
