{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,6,20]],"date-time":"2025-06-20T23:10:01Z","timestamp":1750461001858,"version":"3.41.0"},"reference-count":6,"publisher":"Cambridge University Press (CUP)","issue":"2","license":[{"start":{"date-parts":[[2005,3,31]],"date-time":"2005-03-31T00:00:00Z","timestamp":1112227200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Econom. Theory"],"published-print":{"date-parts":[[2005,4]]},"abstract":"<jats:p>This solution offers additional insights into the theory of \nblock-tridiagonal Toeplitz matrices. Block Toeplitz matrices have constant \nblocks on each block diagonal parallel to the block main diagonal. A block \npartitioned matrix is said to be block-tridiagonal if the nonzero blocks \noccur only on the block subdiagonal, the block main diagonal, and the \nblock superdiagonal. Block-tridiagonal Toeplitz matrices are particularly \nnice in that they are inexpensive to investigate. Our first observation on \nsuch particular block Toeplitz matrices is easy to check, and its proof is \ntherefore left to the reader.<\/jats:p>","DOI":"10.1017\/s0266466605220273","type":"journal-article","created":{"date-parts":[[2005,4,7]],"date-time":"2005-04-07T18:55:30Z","timestamp":1112900130000},"page":"485-487","source":"Crossref","is-referenced-by-count":0,"title":["Solutions to Problems Posed in Volume 20(1) and 20(2): 04.2.1. A \nRange Equality for Block Matrices with Orthogonal Projectors\u2014Solution"],"prefix":"10.1017","volume":"21","author":[{"given":"Hans Joachim","family":"Werner","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"56","published-online":{"date-parts":[[2005,3,31]]},"reference":[{"key":"S0266466605220273_ref005","unstructured":"Werner, H.J. (1987)C. R. Rao's IPM method: A geometric approach. In M.L. Puri , J.P. Vilaplana , & W. Wertz (eds.),New Perspectives in Theoretical and Applied Statistics, pp.367\u2013382.Wiley."},{"key":"S0266466605220273_ref003","unstructured":"Werner, H.J. (1985b)Weak complementarity and missing observations.Methods of Operations Research 50,421\u2013439."},{"key":"S0266466605220273_ref006","unstructured":"Werner, H.J. (2003)Product of two Hermitian nonnegative definite matrices. Solution29-5.4.IMAGE, The Bulletin of the International Linear AlgebraSociety 30,25."},{"key":"S0266466605220273_ref001","unstructured":"Tian, Y. (2003)A range equality for block matrices.IMAGE, The Bulletin of the International Linear AlgebraSociety 31,44."},{"key":"S0266466605220273_ref004","doi-asserted-by":"crossref","unstructured":"Werner, H.J. (1986)Generalized inversion and weak bi-complementarity.Linear and Multilinear Algebra 19,357\u2013372.","DOI":"10.1080\/03081088608817730"},{"key":"S0266466605220273_ref002","doi-asserted-by":"crossref","unstructured":"Werner, H.J. (1985a)More on BLU estimation in regression models with possibly singularcovariances.Linear Algebra and Its Applications 67,207\u2013214.","DOI":"10.1016\/0024-3795(85)90197-1"}],"container-title":["Econometric Theory"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0266466605220273","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,20]],"date-time":"2025-06-20T22:35:57Z","timestamp":1750458957000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0266466605220273\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2005,3,31]]},"references-count":6,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2005,12]]}},"alternative-id":["S0266466605220273"],"URL":"https:\/\/doi.org\/10.1017\/s0266466605220273","relation":{},"ISSN":["0266-4666","1469-4360"],"issn-type":[{"type":"print","value":"0266-4666"},{"type":"electronic","value":"1469-4360"}],"subject":[],"published":{"date-parts":[[2005,3,31]]}}}