In mathematics, omega function refers to a function using the Greek letter omega, written ω or Ω.
<math>\Omega</math> (big omega) may refer to:
- The lower bound in Big O notation, <math>f \in \Omega (g)\,\!</math>, meaning that the function <math>f\,\!</math> dominates <math>g\,\!</math> in some limit
- The prime omega function <math>\Omega(n)\,\!</math>, giving the total number of prime factors of <math>n\,\!</math>, counting them with their multiplicity.
- The Lambert W function <math>\Omega(x)\,\!</math>, the inverse of <math>y = x\cdot e^{x} \,\!</math>, also denoted <math>W(x)\,\!</math>.
- Absolute infinity
<math>\omega</math> (omega) may refer to:
- The Wright omega function <math>\omega(x)\,\!</math>, related to the Lambert W Function
- The Pearson–Cunningham function <math>\omega_{m,n}(x)</math>
- The prime omega function <math>\omega(n)\,\!</math>, giving the number of distinct prime factors of <math>n\,\!</math>.