# Search results

1. ### Many body 2nd order energy shift of ground state

This is more of a math question I suppose, but its in the context of calculating the second order energy shift in the ground state energy for a non relativistic collection of electrons. We end up showing that the energy shift has a finite and divergent piece. The divergent bit is proportional...
2. ### Separable Scattering

Homework Statement Obtain the analytic expression for the N-channel T-matrix assuming a separable potential. Hint: assume that T is proportional to V. Specialise your answer to N=1 and perform the required integral to get an explicit form for T, assume the given form for g(k)...
3. ### Eigenvalues using rgg.f

Hey folks, I'm having an issue using a routine from the netlib that is supposed to calculate eigenvalues and eigenvectors. The canned routine can be found here: http://www.netlib.org/seispack/rgg.f I want to find the eigenvalues of a matrix (a more complex hamiltonian), so for my simple...
4. ### Schools Grad school is crushing my soul.

The book we're using for mechanics is "Theoretical Mechanics of Particles and Continua" by Fetter and Walecka. I've never had as much trouble understanding physics as I am now. I am absolutely confounded when it comes to Lagrange multipliers, Euler angles (and other rigid body stuff) and...
5. ### Force on a Torus.

The problem is with calculating the force of a particle by another particle while both particles lie on a torus. By this I mean, if particle i and j are in a box (LxL) and particle i is on the left edge of the box and particle j is on the right edge of the box, the distance used in the force...
6. ### Argon gas in a Box (torus)

So I'm working on a problem where you have 100 argon atoms in a box that obey the Lennard Jones potential. We're using the Verlet method to calculate the position of each particle at the next time step. The issue I'm having has to do with our boundary conditions. We assume that atoms are on a...