The large sieve is a method in analytic number theory that bounds a sum of squares of values of a trigonometric
polynomial sampled at separated points. Let be an integer,
a positive integer, and let
, ...,
be real numbers separated
by at least
modulo 1. For arbitrary complex coefficients
,
Here the distance between
and
modulo 1 is the distance of
to the nearest integer (Montgomery
and Vaughan 1973).
Other forms of the large sieve bound sums of squares over families of number theoretic characters. For example, Goldmakher and Louvel (2013) proved a large-sieve inequality for quadratic characters over number fields.