%0 Journal Article %T On Eigenvalues and Boundary Curvature of the Numerical Rang of Composition Operators on Hardy Space %A Mohammad Taghi Heydari %J Advances in Pure Mathematics %P 333-337 %@ 2160-0384 %D 2015 %I Scientific Research Publishing %R 10.4236/apm.2015.56032 %X

For a bounded linear operator A on a Hilbert space H, let M(A) be the smallest possible constant in the inequality $\"\"$ . Here, p is a point on the smooth portion of the boundary $\"\"$ of the numerical range of A. $\"\"$ is the radius of curvature of $\"\"$ at this point and $\"\"$ is the distance from p to the spectrum of A. In this paper,