Questions tagged [simulations]
The imitation of a real-world process using an analogous process that is easier to control and experiment with.
1,304 questions
0 votes
1 answer
71 views
Does a "High-Level" emergence theory exist to classify and predict macroscopic structures?
In complex systems (e.g., Turing-Complete Cellular Automata, or the physical universe governed by known laws), the evolution atleast on a larger scale seems to behave according to fixed rules, yet ...
- 345
0 votes
0 answers
22 views
How to calculate transition dipole moment computationally? [closed]
Interested to calculate TDM of a molecule in the presence of a dielectric. What is the go-to way right now in research circles?
-4 votes
0 answers
83 views
Conceptually, what's the effect of an exponential gravitational tilt in non-unformal gravity on a Quantum Harmonic oscillator? [closed]
Diving into this topic, I'd like the know whether the results of diving into this question, and/or could be explain very simply using textbook knowledge or if it's a feasibly novel to a degree. Thank ...
0 votes
1 answer
59 views
Are $N$-body perimeters in 2D expected to collapse into a singularity?
Assume a structure of identical unit-mass point particles forming a two-dimensional perimeter (such as a ring), and the only force acting on the structure is the gravitational interaction between the ...
- 52
3 votes
0 answers
68 views
Diffusion equation after one time-step [closed]
Consider the equation: $$ \partial_tu=D\partial_{xx}^2u $$ with reflecting boundary condition at $x=0$ and with $u(x,0)=\delta(x)$ as an initial distribution. First question: How should I understand a ...
- 31
1 vote
1 answer
76 views
Is this 2d revolute joint behavior normal?
I hope this kind of question can be asked here :) . I coded 2 bodies of rectangular shape like show in the image The force (that is applied to only body 1) varies to always be perpendicular to body 1 ...
- 11
5 votes
2 answers
381 views
Active Brownian Particle simulation
I am trying to reproduce the results from the paper "Simulation of the active Brownian motion of a microswimmer, G. Volpe, S. Gigan and G. Volpe, AJP 2014", where they simulation the motion ...
- 85
1 vote
0 answers
76 views
Add healing length to the inverted parabola of Bose-Einstein Condensates
In the non-interacting case, the Gross–Pitaevskii equation, gives an inverted parabola for the Bose–Einstein condensate (BEC) density in 1D: $$n(x) = \mu -\left(\frac{x}{r_{TF}}\right)^2 \ ,$$ where $\...
- 751
0 votes
1 answer
162 views
Available simulation tools for quantum Hamiltonians [closed]
I have a quantum Hamiltonian describing the interaction of several spins. I wanted to try to simulate my system and measure quantities such as the polarization of the spins, the magnetization and ...
2 votes
0 answers
124 views
Modeling decoherence with a Schrödinger equation solver and heat equation solver in tandem through a Wigner transform?
Premise: In the long-wavelength limit, decoherence is modeled with a master equation for the evolution of the density matrix, $$\frac{\partial \rho(x,x',t)}{\partial t} = -\frac{\mathrm{i}}{2m}\Bigg(\...
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1 vote
2 answers
251 views
Why doesn't light have decoherence?
I was thinking that, if one were to make a realistic physics engine, quantum effects could be ignored due to decoherence making them insignificant in the result. However, for light, it seems quantum ...
- 571
1 vote
2 answers
169 views
How to use Runge-Kutta method for rocket in atmosphere? [closed]
Position of missile = P Thrust vector = T Time = t Gravity vector = g I have a simulation on desmos where I have an AIM-9 sidewinder and am trying to make an accurate simulation with atmospheric drag ...
2 votes
1 answer
196 views
Ensuring the stability and validity of a numerical solution for the Fokker-Planck equation
I am developing a finite-difference numerical scheme for solving the Fokker–Planck equation. The scheme is validated by comparing its solutions with histograms constructed from trajectories of the ...
- 41
2 votes
0 answers
76 views
How should PM compare to Zeldovich approximation before shellcrossing in 2D with plane waves? [closed]
I attempted to do a N-body-simulation and compare it to the analytical Zeldovich map until shell-crossing appears. In order to do so, I placed them uniformly with the Zeldovich initial condition, e.g ...
- 21
1 vote
1 answer
121 views
Trying to prove that a rolling circle on the ground maintains its motion [closed]
I was trying to prove that a rolling circle on the ground will always roll with the same motion. I tried to model this problem as two circles rolling against each other, and then, I want to show that ...
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