- (quantum mechanics) a wavefunction
- (electrical engineering) Electric flux.
Some texts use Ψ (uppercase) for the actual wavefunction that appears in the time-dependent Schrödinger equation, and ψ (=ΨeiEt/ħ) (lowercase) for the time-independent spatial wave function that may exist for stationary states (and which then appears in the time-independent Schrödinger equation), but this distinction is not always observed. Otherwise, the distinction may be made by providing the arguments.
ψ • (ps) (lowercase, uppercase Ψ)
- The lower case letter psi (ψι), the 23rd letter of the modern Greek alphabet.
- ψ΄ (ps΄, “700”)
- ͵ψ (͵ps, “700,000”)
- Appendix:Greek alphabet
- (Greek-script letters) Α α (A a), Β β (B b), Γ γ (G g), Δ δ (D d), Ε ε (E e), Ζ ζ (Z z), Η η (Ē ē), Θ θ (Th th), Ι ι ℩ (I i ℩), Κ κ (K k), Λ λ (L l), Μ μ (M m), Ν ν (N n), Ξ ξ (X x), Ο ο (O o), Π π (P p), Ρ ρ (R r), Σ σ ς (S s s), Τ τ (T t), Υ υ (U u), Φ φ (Ph ph), Χ χ (Kh kh), Ψ ψ (Ps ps), Ω ω (Ō ō)
- (punctuation) · ;
- (diacritics) ᾿ ῾ ´ ` ῀ ¨ ¯ ˘