caa a22 4500 469043687 CHVBK 20180323132818.0 cr unu---uuuuu 170328e19920301xx s 000 0 eng 10.1007/BF01204236 doi (NATIONALLICENCE)springer-10.1007/BF01204236 Bakonyi Mihály Department of Mathematics, The College of William and Mary, 23187-8795, Williamsburg, Virginia aut Completion of operator partial matrices associated with chordal graphs [Elektronische Daten] [Mihály Bakonyi] H. Dym and I. Gohberg established in [6] necessary and sufficient conditions for the existence and uniqueness of an invertible block matrix F=(Fij)i,j=1,...,n such that Fij=Rij for |i−j|≤m and F−1 has a band triangular factorization and so (F−1)ij=0 for |i−j|>m. Here Rij, |i−j|≤m are given block matrices. The aim of this paper is to generalize these results in two directions. First, we shall allow Rij to be an (linear bounded) operator acting between the Hilbert spaces Hj and Hi. Secondly, the set of indices of the given Rij will be more general than banded ones. In fact, we will consider index sets which have an associated graph which is chordal. The case of partial positive operator matrices is also discussed. Birkhäuser Verlag, 1992 Primary 47A20 nationallicence 15A23 nationallicence Secondary 05C50 nationallicence Integral Equations and Operator Theory Birkhäuser-Verlag 15/2(1992-03-01), 173-185 0378-620X 15:2<173 1992 15 20 https://doi.org/10.1007/BF01204236 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01204236 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Bakonyi Mihály Department of Mathematics, The College of William and Mary, 23187-8795, Williamsburg, Virginia aut NATIONALLICENCE 773 0- Integral Equations and Operator Theory Birkhäuser-Verlag 15/2(1992-03-01), 173-185 0378-620X 15:2<173 1992 15 20 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer