Letters in linear algebra

LETTERS IN LINEAR ALGEBRA Editor-in-Chief

George

Phillip

Barker

Department of Mathematics 211 Geology-Physics Building Universitv of Missouri-Kansas Kansas Cky, Missouri 64110 Advisoy

City

Book Review Editor

Editors

Marvin Marcus

Olga Taussky Todd

Stephen L. Campbell

Department of Mathematics University of California Santa Barbara, California 93106

Department of Mathematics California Institute of Technology Pasadena. California 91109

Department of Mathematics North Carolina State Universit) Raleigh, North Carolina 27607

Hans Schneider

Richard S. Varga

Department of Mathematics University of Wisconsin Madison, Wisconsin 53706

Department of Mathematics Kent State University Kent, Ohio 44240

Associate Editors Stephen Barnett

Thomas Hawkins, Jr.

Uriel Rothbhun

University of Bradford West Yorkshire. Bradford BD7 IDP. England

14 Frost Road Belmont, Maine

School of Orgamzation and Management Yale University 5& HilIhouse Avenue New Haven. Connecticut

Richard A. Brualdi Department of Mathematics University of Wisconsin Madison, Wisconsin 53706

Bryan Cain Department of Mathematics Iowa State University Ames. Iowa SO011

Wolfgang

Eichhom

Universitiit Karlsmhe D-7500 Kartsmhe Kaiserstrasse 21,

GIX”M”Y Ky Fan

Department of Mathematics University of California Santa Barbara, California 93106

02178

Charles Johnson Institute for Physical Science and Technology University of Maryland College Park. Maryland 20742

Eugene Seneta Department of Mathematical

Yuri A. Kuznetsov Computing Center

Statistics University of Sydney N.S.W. 2006, Australia

Academic Novosibink

City 630 090. USSR

06520

Ernst Straus

Thomas Laffey Department of Mathematics University College Dublin 4. Ireland

Department of Mathematics University of California -LAX Angele\ Los Angeles, California 93106

Carl D. Meyer

Robert Thompson

Department of Mathematics North Carolina State University Raleigh, North Carolina 27807

Department of Mathematu University of Cahfomia Santa Barbara, California 93106

Morris Newman

Roy Westwick

Department of Mathematics University of California Santa Barbara, California 93106

Department of Mathematics University of British Columbia Victoria, B.C., Canada

Shmuel Friedland

Graciano

Department of Mathematics University of Wisconsin Madison. Wisconsin 5’3708

Institute de Mathematics Universxiade de Cmmbra Coimbra. Portugal

de Oliveira

Harold Wimmer Department of Mathematlrs University of Wurzhurg W&burg, Germany

DIANE VALI~IE OUELLEXTE(Montreal, Quebec, Canada) Schur Complements and Statistics. . . . . . . . . . . . . . . . . . . . . . . 187

Alms and Scope Letters in Linear Algebra publishes surveys and research minisurveys in linear algebra. Surveys are research expository articles. Minisurveys are shorter state-of-the-art surveys which collate results of several authors (including perhaps previously unpublished results of the writer). The surveys, even though they may lead to the periphery of current work, should be an introduction to a specific area or application for people in related areas. The scope of the journal is matrix theory and finite dimensional linear algebra and their history in their algebraic, analytic, arithmetic, combinational, or numerical aspects, and significant applications to other branches of mathematics and other sciences. Manuscripts may be submitted to the Editor-in-Chief or to any member of the Editorial Board. Manuscripts may be written in either English, French, or German. Authors should submit two copies of a manuscript. The form of the manuscript and copyright transfer information is the same as for Linear Algebra and its Applications.