Questions tagged [computational-physics]

Questions with this tag should be about computational physics, which is the study of physical situations with the use of software (commercial or in-house). 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.

Filter by
Sorted by
Tagged with
0
votes
0answers
17 views

Modeling of Spatial Filtering of aberrated beam (~10mm) with Pinhole (~10μm) in 4f-Configuration -> size-constraints

I am trying to simulate a spatial filter in 4f-Configuration with an aberrated input beam to get a feeling for the remaining intensity and wavefront error depending on the pinhole size & ...
0
votes
1answer
34 views

Height oscillations in orbit induced from lunar gravity

I am trying to numerically solve the orbit of a space probe around the moon in a non-spherical gravitational field . $ \Large \begin{align} \frac{d^{2} x}{dt^2} = - \frac{G M x}{(x^2 + y^2)^{3/2}} - \...
2
votes
1answer
66 views

Modelling sky noise using a 2D array with plane waves

I have a question about modeling sky noise which should be filtered by a spatial filter 4f system. My approach for this task is to use a 2D array with random amplitude values and another 2D array that ...
1
vote
1answer
28 views

Apparent horizon buildup in a BH merger

I just read some articles about binary BH merger simulation. These state that at a certain instant a common apparent horizon(or MOTS) appears, surrounding the two BHs. This instant is called the ...
0
votes
0answers
21 views

Which is the Best Free Physics Simulator that can simulate the dropping of a ball? [duplicate]

We were asked in class to use a physics simulator beforehand to test the conditions of an experiment we are going to do and save it to use in our report. The experiment involves the dropping of a ball ...
1
vote
1answer
64 views

Reducing the Hamiltonian size by using a symmetry to speed computations

Say I have some Hamiltonian $\mathcal{H}$ that describes a 1-D spin chain (i.e. Heisenberg model) which has a number of compatible symmetries $\{\mathcal{O}^i\}$ (i.e. total spin...etc). For all $\...
0
votes
0answers
16 views

For a Thermo-Calc database, is it possible to view the equation/parameters of the Gibbs free energy models?

I want to get the equations that model free energy for a given phase in a given alloy system (see attached image). I do not just want to get values of free energy for specific compositions. Is it ...
-1
votes
1answer
189 views

Using air resistance (drag) in Python calculation

I am simulating a free fall with a function that needs to calculate the time it takes for a particular object to reach the surface, I got this program working without accounting for air resistance.. ...
0
votes
1answer
64 views

Numerical modeling of induced voltage

I have an arbitrary magnetic field that varies with time, and I'm trying to numerically model the induced current in a resistive loop over time. Details below. I'm building an electromagnetic ...
0
votes
0answers
30 views

What is the ideal software to simulate a falling maple seed (samara)?

I am completely new to the domain of CFD, so kindly pardon my ill-terminology ;p The task I have requires me to simulate the falling of a maple seed (or an equivalent CAD model) to record its vertical ...
0
votes
0answers
94 views

4-fermion interaction - vertices calculation with Feynrules

Dear Feynrules users and all physics enthusiasts, I was going to derive the 4-fermion vertices in Feynrules and to pass the generated model further to MadGraph and/or CalcHep. According to the most ...
3
votes
2answers
71 views

Using Runge-Kutta method with measurements of acceleration (what to do with half-steps?)

I'd like to perform a short-time motion estimation based on measurements from an Inertial Measurement Unit. If I use the Runge-Kutta method, I will need to compute the k values at half-time steps (Ref)...
0
votes
0answers
33 views

Verifiation the proof of mechanism represent by formula $pv^{(2-\gamma)}$=constant

I was evaluating equation $\frac{du}{dv}=-p$ and $u=\frac{1}{\gamma-1}pv$ which is internal energy of gas,by solving this equation, one will get $\frac{dp}{dv}=-\gamma \frac{p}{v}$,solving this DE ...
1
vote
0answers
47 views

Numerical integration of overdamped Langevin equation: explicit methods?

Assume we have a generic overdamped Langevin equation $$ \frac{d {\bf{x}} }{dt} = {\bf{f}}({\bf{x}}) + B {\bf{w}}(t) $$ where $\bf{f}$ is a deterministic external (and fixed) force field (non ...
0
votes
1answer
79 views

How to compute the divergence of a measured vector field?

The divergence a 2D vector Field $\mathbf{F}(x,y) = F_x(x,y)\, \hat{i} + F_y(x,y)\, \hat{j}$ is defined as $$\mathrm{div}\,\mathbf{F} = \bigg( \dfrac{\partial F_x}{\partial x} + \dfrac{\partial F_y}{\...
3
votes
1answer
66 views

What is the relationship between lattice field theory and grid-based numerical methods?

I recently learned of lattice field theory wherein quantum fields are defined on a discrete spacetime. Naively this sounds to me a lot like certain numerical methods for solving differential equations ...
0
votes
2answers
132 views

Bond Orientational Correlation Function

Firs this question has some similarity with Bond order correlation function and Bond Orientational Correlation Function - how exactly to calculate but its a little bit different , so having those ...
3
votes
1answer
146 views

How to choose Pseudopotential for DFT calculation?

I am beginner and newly started running DFT calculations to find out electronic band structure of certain materials in Quantum Espresso.But we have to select the pseudopotential for running scf loop. ...
2
votes
1answer
45 views

Do neutron star merger studies probe beyond vacuum GR?

When mergers involving neutron stars and / or black holes are simulated (e.g. when predicting gravitational wave signatures for these mergers), obviously complicated numerical relativity calculations ...
1
vote
1answer
97 views

Generating Ising model steady state configurations

What is the most efficient way to simulate steady state configurations of the Ising model? I am just interested in having a large set of random steady state configurations of the 1D Ising model (with ...
1
vote
1answer
52 views

Restrictions on Initial Values for the first derivatives of a wavefunction, for a bound state in the time independent Schrödinger Equation?

The time independent wave function for a bound state given some potential function $V(r)$ is given by the time independent Schrödinger Equation $$E\Psi=-\frac{\hbar^2}{2m}\left(\frac{\partial^2\Psi}{\...
0
votes
0answers
21 views

Church–Turing–Deutsch principle

In what sense from the  Church–Turing–Deutsch follows that it is possible to simulate with one physical system all the other physical systems? I know that we can build logic circuits with a Toffoli ...
1
vote
2answers
65 views

How can I quantify the “temperature” of a system that is still evolving?

My system is a bunch of charged particles in a 1 dimensional harmonic potential. This is a computer simulation, and what I get is a list of the positions and velocities of each particle at every time ...
0
votes
0answers
47 views

Books and courses on Computational quantum mechanics

Can you please suggest the best book and course available on computational quantum mechanics using Mathematica and python or Matlab.
0
votes
1answer
99 views

Acceleration function of position and time

I have an acceleration function in python with position and time parameters and returns the acceleration value. I need the end velocity at a position ,start velocity is zero. how to calculate this ...
0
votes
0answers
20 views

Lattice Boltzmann method: properties of D2Q37 stencil and beyond

I am new in the world of Lattice Boltzmann method (LBM). I have just found in this paper [1] the following statement: A D2Q37 Lattice Boltzmann scheme correctly reproduces the equation of state of ...
0
votes
0answers
12 views

Initial Conditions for no-slip velocity (Walls)

For CFD initial condition, I want to know if i have to apply a very high velocity gradient on the wall of a pipe (internal flow) as it's the case when you study the freestream flow which surrounds an ...
0
votes
0answers
22 views

Monte Carlo sampling libraries for many-body Hamiltonians

This is possibly a very broad resource request question. I would like to know about the various Monte-Carlo libraries/codes that are used by researchers for sampling from the ground states or thermal ...
0
votes
1answer
32 views

Calculation of thermal expansion

how are the thermal expansion of a solid and the stress tensor related? \begin{equation} \int_{\mathbb{R}^{3N}}\frac{\Delta E_p}{\Delta V}\rho_{H_h}(u)du=\frac{2}{3V}\int_{\mathbb{R}^{3N}}E_p\rho_{...
0
votes
0answers
27 views

Self-Consistent Ab Initio Lattice Dynamics

I would kindly like to know if anyone knows the QSCAILD method and if the schematic I wrote is correct. I referred to the following articles: https://arxiv.org/abs/2006.12867 and https://journals.aps....
0
votes
0answers
15 views

Explanation of track formation in scintillators(CsI:Tl)

So I was recently reading some papers on scintillation in inorganic materials like CsI: Tl. In all papers, cylindrical track formation has been mentioned. I understood that there is an incident gamma ...
0
votes
0answers
30 views

What would be the best potential functions for testing my numerical simulation of a wavefunction?

I created a numerical simulation of a wavefunction of a single particle in one dimension of space using excel. I tried putting the potential function $$\Large{V=\frac{\left(i\frac{\partial\Psi}{\...
1
vote
1answer
46 views

How I simulate this in CST Studio? [closed]

I am trying to simulate this coaxial transmission line setup for EMI shielding. Placed the Aluminium sample as seen below (in the middle). I am new on this software, learned simulating the coaxial ...
4
votes
3answers
186 views

Are quantum computers able to simulate every physical process that a classical one can simulate?

I edited the question since this comment was (rightly) made: There are few things that are more annoying than questions where the question text is not self-contained. So: Quantum supremacy has been ...
1
vote
1answer
342 views

Estimating the heat capacity of ising model

I am have written a Metropolis-Hastings algorithm and am currently trying to compare it to the analytical results for the 2D Ising model. The free energy seems reasonable but the heat capacity I'm ...
0
votes
0answers
23 views

Accelerometer readings simulation

I wrote software which generates a trajectory in an inertial frame. I'm trying to simulate an accelerometer reading, as if this accelerometer were moving along this trajectory. If this trajectory does ...
1
vote
1answer
54 views

Is there software or code that is used to simulate hot ion plasma?

How are hot plasma simulated like fluid particles in CFD? Note: If this question is topic, i will eventually delete question but i only need an answer.
1
vote
1answer
223 views

Numerically calculating Berry curvature in >2-band 2D systems?

The standard method for numerically calculating the Berry curvature of a 2D condensed matter system is given by Fukui-Hatsugai-Suzuki in this paper. They discretize $k$-space into a grid with tiny ...
2
votes
0answers
210 views

Deriving a model of a point-driven Chladni plate

Please note — this question considers a point-driven Chladni plate, not Chladni's classical experiment. I'm aware of various other questions concerning the latter here on Physics.SE. As the title ...
0
votes
0answers
34 views

Approximating the wave function of a bound state using a numerical method

Looking at the Schrödinger Equation $$i\hbar\frac{\partial\Psi}{\partial{t}}=\frac{-\hbar^2}{2m}\left(\frac{\partial^2\Psi}{\partial{x^2}}+\frac{\partial^2\Psi}{\partial{y^2}}+\frac{\partial^2\Psi}{\...
2
votes
2answers
56 views

Algorithm for solving electromagnetic problems using only forces

Is there any fundamental issue to solving electromagnetic problems with the following algorithm? (practicality aside) i) Set position, velocity, mass and charge for a set of particles. ii) Compute the ...
4
votes
1answer
61 views

Algorithm to calculate diffusion coefficient

According to the Einstein relationship, the diffusion coefficient $D$ is $$\lim _{t\rightarrow \infty} \frac{\langle \left(\mathbf{r}(t)-\mathbf{r}(0) \right) ^2\rangle}{6t} = D$$ I have run a MD ...
0
votes
1answer
61 views

Is there such thing as well defined physics and math for atomic interactions? [closed]

We have a lot of good Newtonian physics simulation software out there (Bullet, PhysX, Havok, etc.), but I see none good for simulating atomic interactions (going deeper). I like to build one for ...
2
votes
0answers
65 views

$E\times B$ drift in strongly nonuniform fields

Potential is defined as $\{\phi,\, 0,\, A,\, 0 \}$; fields are static and depend only on the axial coordinate $x$: $E_x=-\partial_x\phi$, $B_z=\partial_x A$. Charged particle moves in the $\{x,y\}$-...
1
vote
0answers
57 views

Question about the VEGAS-algorithm for numerical integration

Disclaimer: I am not quite sure if this question belongs to Physics SE, if not feel free to move it. Question: I am currently using the VEGAS-algorithm (See e.g. here and here) and i am trying to ...
14
votes
12answers
3k views

Is there an equivalent of computation of physical processes in nature? [closed]

I was watching a waterfall in the Austrian Alps. There were thousands of water droplets falling down, splattering on the stones below. I thought - how does nature find out so quickly where each ...
0
votes
0answers
139 views

Root Mean Square Displacement of Diffusion and Radial Diffusion Function

I read, that for normal diffusion the root mean square displacement $\sqrt{\langle x^2(t)\rangle}$ (for particles at the origin) can be interpreted as the mean distance the particles have with respect ...
4
votes
2answers
225 views

Canonical rotations that do not produce computational singularities

Intro On the topic of dynamical systems associated with 3-dimensional rotation of rigid bodies, you will always encounter singularities in the equations of motion that will produce computational ...
0
votes
0answers
88 views

Solving the Lane-Emden equation via Chebyshev differentiation matrices

Problem So I'm trying to learn spectral methods but I can't quite proceed for some reason. In particular, I have been trying to solve the Lane-Emden equation (which I know how to solve via ...
1
vote
1answer
60 views

Discrete Harmonic Oscillator matrix representation of $x$ for Quantum Simulation

(The paper I'm referring to in this question is "Quantum simulations of one dimensional quantum systems") I've been trying to understand the paper above, specifically on constructing a ...

1
3 4
5
6 7
29