Probability density may refer to:
- Probability density function in probability theory
- The product of the probability amplitude with its complex conjugate in quantum mechanics
According to quantum mechanics, these two are the same thing.
Famous quotes containing the word probability:
“Only in Britain could it be thought a defect to be “too clever by half.” The probability is that too many people are too stupid by three-quarters.”
—John Major (b. 1943)