Lévy's continuity theorem
In probability theory, Lévy’s continuity theorem, or Lévy's convergence theorem, named after the French mathematician Paul Lévy, connects convergence in distribution of the sequence of random variables with pointwise convergence of their characteristic functions.
This theorem is the basis for one approach to prove the central limit theorem and it is one of the major theorems concerning characteristic functions.Statement
Suppose we have
If the sequence of characteristic functions converges pointwise to some function
then the following statements become equivalent:Proof
Rigorous proofs of this theorem are available.
