Apparently, this user prefers to keep an air of mystery about them.
5 If $A^2$ is a matrix such that $A^2 - A + I = 0$ show that $A$ is invertible with inverse $I - A$. oct 25 '13
2 Is zero vector potential for Helmholtz decomposition of curl and divergence free vector fields necessary? dec 5 '13
1 finite difference method for nonlinear ode dec 4 '13