Hyperdeterminant and an integrable partial differential equation

We discuss an integrable partial differential equation arising from the hyperdeterminant

Hamilton Operators, Discrete Symmetries, Brute Force and SymbolicC++

To find the discrete symmetries of a Hamilton operator $\hat H$ is of central importance in quantum theory. Here we describe and implement a brute force method to determine the discrete symmetries given by permutation matrices for Hamilton operators acting in a finite-dimensional Hilbert space. Spin and Fermi systems are considered as examples. A computer algebra implementation in SymbolicC++ is provided

Spin Hamilton Operators, Symmetry Breaking, Energy Level Crossing and Entanglement

We study finite-dimensional product Hilbert spaces, coupled spin systems, entanglement and energy level crossing. The Hamilton operators are based on the Pauli group. We show that swapping the interacting term can lead from unentangled eigenstates to entangled eigenstates and from an energy spectrum with energy level crossing to avoided energy level crossing