A unified version of Cauchy–Schwarz and Wielandt inequalities Original Research Article

Let A be an n×n positive definite symmetric real matrix with n eigenvalues λ1,λ2,…,λn and let x and y be two n×1 vectors with the angle ψ. This paper proves the following inequalityimageIt is a unified version of the Cauchy–Schwarz inequality and the Wielandt one.