Totally positive matrices;
Point-line incidences;
Bruhat order of permutations;
Outerplanar graphs;
D O I:
10.1016/j.laa.2014.04.007
中图分类号:
O29 [应用数学];
学科分类号:
070104 ;
摘要:
We show that the maximal number of equal entries in a totally positive (resp. totally nonsingular) n-by-n matrix is theta(n(4/3)) (resp. theta(n(3/2))). Relationships with point-line incidences in the plane, Bruhat order of permutations, and TP completability are also presented. We also examine the number and positionings of equal 2-by-2 minors in a 2-by-n TP matrix, and give a relationship between the location of equal 2-by-2 minors and outerplanar graphs. (C) 2014 Elsevier Inc. All rights reserved.
机构:
INRIA Saclay Ile De France, Palaiseau, France
CNRS, CMAP, Ecole Polytech, Palaiseau, France
Ecole Polytech, CMAP, Route Saclay, F-91128 Palaiseau, FranceINRIA Saclay Ile De France, Palaiseau, France
Stephane, Gaubert
Adi, Niv
论文数: 0引用数: 0
h-index: 0
机构:
Kibbutzim Coll Educ, Fac Sci, Tel Aviv, Israel
149 Namir Rd, Tel Aviv, IsraelINRIA Saclay Ile De France, Palaiseau, France