. . "31" . . "0895-4798" . "Liesen, J." . . . . "[A4991D88A1D3]" . "We show that certain matrix approximation problems in the matrix 2-norm have uniquely defined solutions, despite the lack of strict convexity of the matrix 2-norm. The problems we consider are generalizations of the ideal Arnoldi and ideal GMRES approximation problems introduced by Greenbaum and Trefethen [SIAM J. Sci. Comput., 15 (1994), pp. 359-368]. We also discuss general characterizations of best approximation in the matrix 2-norm and provide an example showing that a known sufficient condition for uniqueness in these characterizations is not necessary." . . . "11"^^ . . . "P(IAA100300802), Z(AV0Z10300504)" . "SIAM Journal on Matrix Analysis and Applications" . "2"^^ . "000270196000004" . "1"^^ . "Tich\u00FD, Petr" . . . "331336" . . "2" . . "RIV/67985807:_____/09:00330308!RIV10-AV0-67985807" . "We show that certain matrix approximation problems in the matrix 2-norm have uniquely defined solutions, despite the lack of strict convexity of the matrix 2-norm. The problems we consider are generalizations of the ideal Arnoldi and ideal GMRES approximation problems introduced by Greenbaum and Trefethen [SIAM J. Sci. Comput., 15 (1994), pp. 359-368]. We also discuss general characterizations of best approximation in the matrix 2-norm and provide an example showing that a known sufficient condition for uniqueness in these characterizations is not necessary."@en . "On Best Approximations of Polynomials in Matrices in the Matrix 2-Norm"@en . . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . . "On Best Approximations of Polynomials in Matrices in the Matrix 2-Norm" . . "On Best Approximations of Polynomials in Matrices in the Matrix 2-Norm" . "matrix approximation problems; polynomials in matrices; matrix functions; matrix 2-norm; GMRES; Arnoldi's method"@en . . . "RIV/67985807:_____/09:00330308" . "On Best Approximations of Polynomials in Matrices in the Matrix 2-Norm"@en . .