Recent content by TimeFall

Awesome, thanks! I'll give that a whirl and see what happens.

Hello! Thanks for responding. I'm not using H, a, and z in this loop, no. They are saved and used later in the code. I just needed this function to get their values. The way I understood the gsl to work is that it updated the values of y[] and worked with those, and so I was saving their...

Thanks! Here's the function where I actually do the integration (I've left out the #includes and variable declarations in the interest of space) double y[3] = {Par.theta, Par.phi, Par.H_init}; // Set up ode system and driver gsl_odeiv2_system sys = {system_def, jacobian, 3}...

Hello! I'm studying various dark energy models, and as a part of the project, I need to be able to numerically solve the Klein-Gordon (KG) equation and the Friedmann Equation (FE) in the context of a canonical scalar field. I wasn't sure whether or not this belonged here or in the computational...

Hey .Scott, thanks for replying! There is more than one cell. I probably should have been more explicit in my description of the problem. What I'm doing is dividing up the simulation volume (which has periodic boundary conditions, so if one sph smoothing sphere goes off the edge of the...

Hello! I'm currently working on an algorithm that converts SPH (smoothed particle hydrodynamics) data to an Eulerian grid. Basically, the problem is this: each sph particle has an associated smoothing length, which is effectively the radius of a sphere centered at the sph particle's position...

Hello! Well, I guess it's all in the title, really. I was reading about k-essence, and it was described as a scalar field having a non-canonical kinetic term. I did a bit of browsing and couldn't find a clear explanation of what, exactly, a non-canonical kinetic term is. Any help would be...

Thank you very much! I totally forgot about expanding the metric, as well as the delta condition.

EDIT: Used proper tex (hopefully!) Hello! I'm working through Weinberg's book Gravitation and Cosmology, and I'm currently in chapter 13, symmetric spaces. I'm trying to follow his derivation of the Killing condition, and I simply cannot, for the life of me, get from equation 13.1.2 to equation...

Thank you!

See below. I screwed up the edit and the use of tex.

Hello! This is my first post, so go easy on me! I'm working through Scott Dodelson's book Modern Cosmology http://books.google.com/books?id=3oPRxdXJexcC&pg=PA23&source=gbs_toc_r&cad=4#v=onepage&q&f=false and I am a bit confused about equation 2.85: $$\rho_{DE} \propto e^{-3 \int^a...