Recent content by felix00

Thanks a lot to everyone, your answers made it way clearer than my old course notes! I managed to put together a simple Runge-Kutta integrator and got meaningful trajectories. Made my day! However it seems quite slow. I am doubting it is possible to have real-time raytraced rendering in a...

I think my code has the -+++ convention, if by that you mean the sign of the diagonal matrix elements of g. Regardless of my choice of initial dx^0/ds the result of g_mn v^m v^n (sorry I cannot figure out how to put nice tex code) is negative, provided that the initial radial velocity and theta...

Thanks again! I used the spherical coordinates, and cooked up a quick s-step integrator which is probably wrong/inaccurate. I'll do some more research to improve it. Nevertheless I got somewhat reasonable. https://www.dropbox.com/s/x1bilwwsk861iyj/GR.png?dl=0...

Thanks a lot! this is very helpful! Just a few points are not clear, mostly because it has been ~10 years since my GR course (that I didn't fully understand anyway). The whole high/low indexing confuses me a bit. 1) [ itex ] x^0 = t, x^1 = x, x^2=y, x^3=z [ /itex ] I noticed the high indexes...

Hi, I'm Filippo, researcher in Aalto University. I enjoy making numerical simulation methods. Hope I can contribute here and find expert answers to my endless curiosity. Cheers!

Hi,I'd like to build a simulation (realtime) of space ships near a black hole (neutral, still or rotating possibly). Key features would be: 1) the ships are test particles that do not affect the metric a) possibly test rigid-bodies with GR consistent rotational DOF. 2) the ships can fire...