The minimum number of nonzero entries in an n by n orthogonal matrix which has a column of nonzeros is known to be In this note the sparsity of orthogonal matrices which have both a column and a row of nonzeros is studied. For each integer n 2 we construct an n by n orthogonal matrix which has both
-Orthogonal matrices
β Scribed by Ma. Nerissa M. Abara; Dennis I. Merino; Agnes T. Paras
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 231 KB
- Volume
- 432
- Category
- Article
- ISSN
- 0024-3795
No coin nor oath required. For personal study only.
β¦ Synopsis
Let S β M n (R) be such that S 2 = I or S 2 = -I.
is unitary, and both factors are Ο S -orthogonal. We show that if A is Ο Sorthogonal and normal, and if -1 is not an eigenvalue of A, then there exists a normal Ο S -skew symmetric N (that is, Ο S (N) = -N) such that A = e iN . We also take a look at the particular cases S = H k β‘ 0 I k -I k 0 and S = L k β‘ I k β -I n-k .
π SIMILAR VOLUMES
Using the notion of quantum integers associated with a complex number q = 0, we define the quantum Hilbert matrix and various extensions. They are Hankel matrices corresponding to certain little q-Jacobi polynomials when |q| < 1, and for the special value q = (1- they are closely related to Hankel
Let G be a graph and let c(x,y) denote the number of vertices in G adjacent to both of the vertices x and y. We call G quadrangular if c(x,y) ~ 1 whenever x and y are distinct vertices in G. Reid and Thomassen proved that IE(G)I >t 21V(G)I -4 for each connected quadrangular graph (7, and characteriz