On the inequality w(AB) ≤ c||A||w(B) where A is a positive operator
On the inequality w(AB) ≤ c||A||w(B) where A is a positive operator
Abu-Omar and Kittaneh [Numerical radius inequalities for products of Hilbert space operators, J. Operator Theory 72(2) (2014), 521-527], wonder what is the smallest constant c such thatw(AB) ? c||A||w(B) for all bounded linear operators A, B on a complex Hilbert space with A is positive. Here, w(?) stands for the …