Perturbation Theory Sample Clauses
Perturbation Theory. If ||Γˆ|| is sufficiently small, J can be treated by perturbation theory, along the lines used to derive the ▇▇▇▇▇▇-▇▇▇▇▇▇ distribution of resonance widths [41] (see also [42] for the case of a single absorbing channel L = 1). To first order, the imaginary parts of the zeros are independent of the real parts and given by Yn = ⟨n|Γˆ|n⟩ = Σ γm|⟨n|wm⟩|2 − Σ ρl|⟨n|wK+l⟩|2,
l=1 K L m=1 l=1 δ y − β m=1 K —∞
(1 + 2ikγ eiky /β) β QL
(1 − 2ikρ /β) β 2π