MacDonald, Gordon W. “Distance from Projections To Nilpotents”. Canadian Journal of Mathematics - Journal Canadien de Mathematiques, vol. 47, no. 4, 1995, pp. 841-5, https://scholar2.islandarchives.ca/islandora/object/ir%3Air-batch6-1559.

Genre

  • Journal Article
Contributors
Author: MacDonald, Gordon W.
Date Issued
1995
Abstract

The distance from an arbitrary rank-one projection to the set of nilpotent operators, in the space of k x k matrices with the usual operator norm, is shown to be sec(pi/(k+2))/2. This gives improved bounds for the distance between the set of all non-zero projections and the set of nilpotents in the space of k x k matrices. Another result of note is that the shortest distance between the set of non-zero projections and the set of nilpotents in the space of 3 x 3 matrices is root(3-root 5)/2.

Note

MACDONALD, GW, UNIV PRINCE EDWARD ISL,DEPT MATH & COMP SCI,CHARLOTTETOWN,PE C1A 4P3,CANADA.

OTTAWA; 577 KING EDWARD RD, PO BOX 450, STATION A, OTTAWA ON K1N 6N5, CANADA

CANADIAN MATHEMATICAL SOC

PT: J; CR: HEDLUND JH, 1972, MICH MATH J, V19, P249 HERRERO D, 1975, INDIANA U MATH K, V24, P847 HERRERO D, 1982, PITMAN RES NOTES MAT, V72 HERRERO DA, 1981, INDIANA U MATH J, V30, P199 HERRERO DA, 1981, OPERATOR THEORY ADV, V2, P171 POWER S, 1980, MATH P CAMBRIDGE PHI, V88, P327 SALINAS N, 1980, J OPERAT THEOR, V3, P179; NR: 7; TC: 0; J9: CAN J MATH; PG: 11; GA: RR321

Source type: Electronic(1)

Language

  • English

Subjects

  • Mathematics
Page range
841-851
Host Title
Canadian Journal of Mathematics - Journal Canadien de Mathematiques
Host Abbreviated Title
Can.J.Math.-J.Can.Math.
Volume
47
Issue
4
ISSN
0008-414X