The problem of best approximating, a given square complex matrix in the Frobenius norm by normal matrices under a given spectral restriction is considered. The ne cessary and sufficient condition for the solvability ...The problem of best approximating, a given square complex matrix in the Frobenius norm by normal matrices under a given spectral restriction is considered. The ne cessary and sufficient condition for the solvability of the problem is given. A numerical algorithm for solving the problem is provided and a numerical example is presented.展开更多
Let F be a family of meromorphic functions on the unit disc A. Let a be a non-zero finite value and k be a positive integer. If for every f ∈ F,(i) f and f(k) share α ;(ii) the zeros of f(z) are of multiplicity ≥k ...Let F be a family of meromorphic functions on the unit disc A. Let a be a non-zero finite value and k be a positive integer. If for every f ∈ F,(i) f and f(k) share α ;(ii) the zeros of f(z) are of multiplicity ≥k + 1 , then F is normal on △.We also proved corresponding results on normal functions and a uniqueness theorem of entire functions .展开更多
文摘The problem of best approximating, a given square complex matrix in the Frobenius norm by normal matrices under a given spectral restriction is considered. The ne cessary and sufficient condition for the solvability of the problem is given. A numerical algorithm for solving the problem is provided and a numerical example is presented.
文摘Let F be a family of meromorphic functions on the unit disc A. Let a be a non-zero finite value and k be a positive integer. If for every f ∈ F,(i) f and f(k) share α ;(ii) the zeros of f(z) are of multiplicity ≥k + 1 , then F is normal on △.We also proved corresponding results on normal functions and a uniqueness theorem of entire functions .
