Thanks, the problem seems very complicated and I think I have to resort to a numerical integration.
However, that would be easier if one could write
\mathcal{I}(\xi,\beta)=f(\beta)\mathcal{I}^{\prime}(\xi)
so this way I would have to integrate only once. Do you see a way to possibly achieve that?
Thank you for your answer. But I don't understand how I can Taylor expand where the integrand diverges.
Also, do you see a way to normalize the integral and/or make it more simple to solve it numerically.
What I find challenging is that for every value of beta I have to numerically solve the...
Hi,
this is not a homework and my problem is much bigger for me to give full details here. I came across this integral
\mathcal{I}(\xi)=\int^{\xi_c}_{\xi}{\rm d}\xi^\prime\exp\left[\sqrt{2}\sigma\,{\rm Erf}^{-1}\left(1-\frac{8\pi}{3}{\xi^\prime}^3\right)\right]
where Erf^{-1} is the...
I won a scolarship two years ago but my supervisor is not really paying for me. But you're right, I have to talk to him as soon as possible. I'm just very afraid of doing it because I think I might lose it and compromise my future. I'm really pissed off because I won the scholarship because I...
It sucks because I only have one year left and I really don't know where else to turn. I do know how to program but I certainly don't have the skills to work in a big company that require senior positions. Do you know where I can look for companies that hire programmers and also offer some sort...
I'm located in Europe and the PhD only last three years. I can program in Python, Fortran and C and I am bilingual.
My supervisor keeps saying that we have to perfect things and he's afraid of comments of possible referees, that's why I'm not publishing anything.
I have a MSc in astrophysics and I'm a last year PhD student. My project is not going anywhere, I haven't published any paper and I'm far from finishing. My advisor is very picky and won't let me publish anything and I'm terrified the last years have been a huge waste of time.
What do you think...
I work with a grid-based code, this means that all of my quantities are defined on a mesh. I need to compute, for every point of the mesh the divergence of the velocity field.
All I have is, for every cell of my mesh, the values of the 3-d velocity in his 26 neighbors.
I call neighbors the...
Sorry but I don't understand how to compute the Ks considering them as arrays. I tried googling it but I couldn't find anything. Can please you make an example?
Ah ok, thanks. So in my case, since I don't have an explicit time dependency the ks should be
k1=hf(x_{i},v_{i})
k2=hf(x_{i}+k1/2,v_{i}+k1/2,)
k3=hf(x_{i}+k2/2,v_{i}+k2/2)
k4=hfx_{i}+k3,v_{i}+k3)
Is that right?
Thanks that helped but I have still some problem in computing v.
According to what you wrote and the runge Kutta IV method definition the k should be:
k1=hf(t_{i},x_{i})
k2=hf(t_{i+1/2},x_{i}+k1/2)
k3=hf(t_{i+1/2},x_{i}+k2/2)
k4=hf(t_{i+1},x_{i}+k3)
How is v for every k?
Homework Statement
I need to solve this differential equation numerically. I hope you can help me, it's not homework!
Homework Equations
This is the equation to be solved
x''=\dfrac{\alpha}{x}-\beta\dfrac{(x'-\gamma x)^2}{x}-\delta x - \dfrac{\varepsilon}{x^2}
The Attempt at a...
My question is not homework. I feel ashamed of having this doubts but I'm really stuck on this.
The problem is I have a reference frame xyz and here I define the COM \vec x{_{cm}} of the system.
Now I move the COM reference frame x'y'z':
\vec{x'}=\vec{x}-\vec x{_{cm}}
In this reference frame I...
You're right! But sorry if I insist, I just want to get this straight.
If I only know the new z-axis and x and y could be in directions, although forming an orthonormal system, does this means that I could choose my angle gamma to be any value between 0 and 2pi?