# Tagged Questions

DO NOT USE THIS TAG just because the question contains numerics!

0answers
710 views

### Interpretation of Stiffness Matrix and Mass Matrix in Finite Element Method

I would like to have a general interpretation of the coefficients of the stiffness matrix that appears in FEM. For instance if we are solving a linear elasticity problem and we modelize the relation ...
0answers
129 views

### Monte Carlo for Random Bond Ising ferromagnet

The set-up: Consider the Ising model on an $L \times L$ square lattice, where the coupling of each bond is chosen to be $+J$ (ferromagnetic) with probability $(1-p)$ and $-J$ (antiferromagnetic) with ...
0answers
66 views

### Degenerated Anderson Model Simulation

I'm trying to simulate the degenerative Anderson model. So depending on an energy difference first orbital and afterwards spin magnetism occurs. First i try to solve an easier ansatz with a limitation ...
0answers
12 views

### Capturing superfluid condensation with exact diagonalization

Doing exact diagonalization on bosonic systems is tricky, because the possibility of multiple occupancy means that even the single-site Hilbert space is infinite-dimensional. It's my understanding ...
0answers
12 views

### Numeric fermiomic creation operators and unit cell

I have to do some numerics (e.g. FFT in Maple/Octave) on a 1D fermionic chain without forces between the particles. The description says that two sites build an unit cell. What does this mean? And ...
0answers
47 views

### How can I get the boundary and initial conditions of the convection–diffusion equation consistant?

I want to solve the 1D convection–diffusion equation. The boundary conditions are a flux in from the bottom and a flux out on the top. Furthermore I want no concentration inside at the beginning. I ...
0answers
31 views

### Solving coupled nonlinear ODEs, controlling numerical instability through numerical viscosity

I'm solving a problem numerically that takes the form $Q_{ij} \ddot{y}_j +S_{ijk}\dot{y}_j\dot{y}_k +V_i=0$, where $(Q_{ij},S_{ijk},V_i)$ are all low order polynomial functions of the dependent ...
0answers
244 views

### Numerical solution of the BCS gap equation, with Coulomb potential

I'm interested in the excitons condensation, which is described by an equation which is very similar to the standard BCS gap equation. I will be referring to this article: http://arxiv.org/abs/cond-...
0answers
117 views

### numerical diagonalisation comparison of complex Hermition matrix and real matrix

we are doing K space calculation(transnational invariant basis) of Hamiltonian, and trying to compare with exact method for same nos of sites and particles, we are getting big difference in ground ...