The general form of this theory, such as that applied to QED, gives rise to Dyson series, and that general form can be used to derive Fermi's golden rule of state transitions.
The general form of this theory, such as that applied to QED, gives rise to Dyson series, and that general form can be used to derive Fermi's golden rule of state transitions. The no level-crossing theorem applies to energy states derived using this theory and when combined with quantum chromodynamics in situations where the coupling constant is small, this theory can be used to calculate the cross section of electron-positron annihilation. Its time independent, non-degenerate form can be used to derive the quadratic Stark effect, while the linear Stark effect is derived from its time-independent degenerate form. It is also used in models of the hydrogen atom to derive splitting due to spin-orbit and spin-spin coupling by adding those relatively small interactions to the larger Hamiltonian, and in classical physics it was applied by Poincare to the 3-body problem. For ten points, identify this theory which is used to approximate solutions by starting with known solutions and expanding a power series in terms of a small parameter.
The general form of this theory, such as that applied to QED, gives rise to Dyson series, and that general form can be used to derive Fermi's golden rule of state transitions.
{perturbation theory} [accept word forms]