All Questions
18
questions
1
vote
1
answer
60
views
Checking the formula for solving the Poisson equation with an integral over all of space
EDIT: According to 2.2.3 Rigorous derivation, if we find the integral $u(x,y) = \int \int G(x,y,m,n)f(m,n) dm dn$ then we obtain a function that satisfies the Poisson equation $\nabla^2u(x,y)=f(x,y)$. ...
- 2,444
0
votes
0
answers
57
views
Help me figure out how to solve the gravitational lens equations [migrated]
I want to simulate gravitational lensing. In the article LENSINGGW: a PYTHON package for lensing of gravitational waves there is this fragment [page 3]:
My research: As far as I understand, this is a ...
- 2,444
2
votes
1
answer
132
views
Solving a ODE (Peeble's Equation) with initial condition a the maximum input range
I have a differential equation which is,
$$
\frac{d X_e}{dz} = \frac{C_r(z)}{H(z)}\times \frac{1}{(1+z)}\Big[\frac{38\eta T^3}{25\pi^2}\alpha (T)X_e^2 - b(T)(1 - X_e) \Big]
$$
Where
$$
\alpha(T) = \...
- 174
3
votes
1
answer
500
views
2 body orbits around a barycenter
I'm attempting to plot a barycentric orbit of the sun and Jupiter.
Initial Conditions
...
- 847
6
votes
1
answer
789
views
gravitational two body problem for the orbit of the sun and jupiter around their barycenter
This is a simulation of the sun and jupiter orbiting the respective barycenter.
Initial conditions
...
- 847
1
vote
0
answers
303
views
0
votes
1
answer
861
views
Plotting elliptical orbits using Verlet method
I'm looking to solve a 2 body system consisting of the Earth and a body of mass in orbit.
I'm using the Verlet method to numerically integrate Newton's equation of motion in order to plot an ...
- 847
-1
votes
2
answers
143
views
a ListAnimate problem
Thanks to @AlexTrounev, I learned how to use ListAnimate, but I still get stuck using it. Before ListAnimate everything is correct. I just cannot successfully use ListAnimate to make the plot. I have ...
- 219
0
votes
1
answer
130
views
0
votes
1
answer
779
views
Animate particle's trajectory
Does anyone know how to animate the trajectory of a particle, but make sure before the particle reaching a certain spot, there's nothing. I mean I want to make an animation that look like https://en....
- 219
8
votes
1
answer
3k
views
Interpreting Mathematica code on black holes
I am trying to understand the code written down on page 7 of this document (code is in Mathematica) I understand pretty much all of the code on the previous page needed to setup the page 7 code (...
- 359
1
vote
1
answer
122
views
TrueAnomaly of planet orbit as a function?
It is possible to obtain the true anomaly of a planet this way:
...
- 777
2
votes
1
answer
650
views
Calculating with scientific notation
I want to calculate the gravitational force between the Earth and its Moon using Newton's gravitational formula: (G M1 M2)/d^2 and its appropriate physical units. I'd include the code I wrote for ...
- 21
5
votes
1
answer
578
views
Lagrangian form of Earth-Sun Kepler blows up NDSolve?
I've looked at this 1-D SE question. That question seems to have difficulties around diverging potential functions, and I don't have that. I've looked at this 2-D 3-body demonstration, but that starts ...
- 8,693
2
votes
0
answers
605
views
Plotting orbits of trajectories of bodies sharing the earth's orbit in coordinates centered at the barycenter of the solar system [closed]
I am attempting to try and plot the trajectories of a trio of satellites that are orbiting with the earth-moon system around the solar system's barycenter. Originally, I had the satellites in orbit ...
- 21