hamiltonian function
61Mean field theory — (MFT, also known as self consistent field theory) is a method to analyse physical systems with multiple bodies. A many body system with interactions is generally very difficult to solve exactly, except for extremely simple cases (random field… …
62Helmholtz free energy — In thermodynamics, the Helmholtz free energy is a thermodynamic potential which measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature and volume. For such a system, the negative of the difference in… …
63Dirac equation — Quantum field theory (Feynman diagram) …
64Potts model — In statistical mechanics, the Potts model, a generalization of the Ising model, is a model of interacting spins on a crystalline lattice. By studying the Potts model, one may gain insight into the behaviour of ferromagnets and certain other… …
65Exchange interaction — In physics, the exchange interaction is a quantum mechanical effect without classical analog which increases or decreases the expectation value of the energy or distance between two or more identical particles when their wave functions overlap.… …
66Riemann hypothesis — The real part (red) and imaginary part (blue) of the Riemann zeta function along the critical line Re(s) = 1/2. The first non trivial zeros can be seen at Im(s) = ±14.135, ±21.022 and ±25.011 …
67Energy — This article is about the scalar physical quantity. For other uses, see Energy (disambiguation). Energetic redirects here. For other uses, see Energetic (disambiguation) …
68Quantum decoherence — Quantum mechanics Uncertainty principle …
69Ritz method — In physics, the Ritz method is a variational method named after Walter Ritz.In quantum mechanics, a system of particles can be described in terms of an energy functional or Hamiltonian, which will measure the energy of any proposed configuration… …
70Calculus of variations — is a field of mathematics that deals with extremizing functionals, as opposed to ordinary calculus which deals with functions. A functional is usually a mapping from a set of functions to the real numbers. Functionals are often formed as definite …
