\Omega
The Greek letter Omega (\Omega) is often used in mathematics and science to represent a variety of concepts, including the last element of a set or sequence, the unit of electrical resistance (ohm), and the sample space in probability theory. It is also used in asymptotic analysis to describe the lower bound of an algorithm's running time.
Represents the sample space in probability theory, consisting of all possible outcomes.
\Omega = \{ \omega_1, \omega_2, \ldots, \omega_n \}
Represents electrical resistance measured in ohms.
R = 50 \, \Omega
Represents the lower bound of an algorithm's running time in asymptotic notation.
f(n) = \Omega(n^2)