What is Theorem on friends and strangers?

Jacobi's four-square theorem gives a formula for the number of ways that a given positive integer n can be represented as the sum of four squares.

In algebraic number theory, the prime ideal theorem is the number field generalization of the prime number theorem. It provides an asymptotic formula for counting the number of prime ideals...

In the mathematical theory of random processes, the Markov chain central limit theorem has a conclusion somewhat similar in form to that of the classic central limit theorem of probability...

In probability theory, the central limit theorem states that, in many situations, when independent random variables are added, their properly normalized sum tends toward a normal distribution. This article gives...

In probability theory, the central limit theorem states that, under certain circumstances, the probability distribution of the scaled mean of a random sample converges to a normal distribution as the...

In mathematics, Bochner's theorem characterizes the Fourier transform of a positive finite Borel measure on the real line. More generally in harmonic analysis, Bochner's theorem asserts that under Fourier transform...

In mathematics, the Balian–Low theorem in Fourier analysis is named for Roger Balian and Francis E. Low.The theorem states that there is no well-localized window function g either in time...

"Best friends forever" is a phrase that describes a close friendship. It is sometimes written as an initialism, "BFF".

Friends of Suburban Bristol Railways is a Bristol-based campaign group, calling for better rail transport in the Bristol area.

"No friends but the mountains" is a Kurdish proverb which is expressed to signify their feeling of betrayal, abandonment and loneliness due to their history as a semi-stateless ethnic minority...