The Representation of a Graph by Set IntersectionsCanadian Journal of Mathematics - Tập 18 - Trang 106-112 - 1966
P. Erdős, A. W. Goodman, L. Pósa
Geometrically, a graph is a collection of points (or vertices) together with a
set of edges (or curves) each of which joins two distinct vertices of the graph,
and no two of which have points in common except possibly end points. Two given
vertices of the graph may be joined by no edge or one edge, but may not be
joined by more than one edge. From an abstract point of view, a graph G is a
collecti... hiện toàn bộ
Abstract Quadratic FormsCanadian Journal of Mathematics - Tập 21 - Trang 1218-1233 - 1969
Irving Kaplansky, R. J. Shaker
We shall be studying the following structure, which we shall call a V-form
(“Vector-valued form”). Let G and W be additive abelian groups with every
element of order 2 (i.e. vector spaces over the field GF(2) of two elements).
Let there be given a symmetric bilinear map from G × G to W; we shall write it
simply as a product ab. We define an equivalence relation on unordered n-ples of
G. For n = 2:... hiện toàn bộ
Classification of Finite Spaces of OrderingsCanadian Journal of Mathematics - Tập 31 Số 2 - Trang 320-330 - 1979
Murray Marshall
1. Introduction. A space of orderings will refer to what was called a “set of
quasi-orderings” in [5]. That is, a space of orderings is a pair (X, G) where G
is an elementary 2-group (i.e. x2 = 1 for all x ∈ G) with a distinguished
element – 1 ∈ G, and X is a subset of the character group x(G) = Horn (G, {1,
–1};) satisfying the following properties:01: X is a closed subset of χ(G).02:
σ(−l) = −1 ... hiện toàn bộ
Tensor Algebras, Induced Representations, and the Wold DecompositionCanadian Journal of Mathematics - Tập 51 Số 4 - Trang 850-880 - 1999
Paul S. Muhly, Baruch Solel
AbstractOur objective in this sequel to [18] is to develop extensions, to
representations of tensor algebras overC*-correspondences, of two fundamental
facts about isometries on Hilbert space: The Wold decomposition theorem and
Beurling’s theorem, and to apply these to the analysis of the invariant subspace
structure of certain subalgebras of Cuntz-Krieger algebras.
Comma-Free CodesCanadian Journal of Mathematics - Tập 10 - Trang 202-209 - 1958
S. W. Golomb, Basil Gordon, L. R. Welch
Let n be a fixed positive integer, and consider an alphabet consisting of the
numbers 1, 2, … , n. With this alphabet form all possible k-letter words (a 1 a
2 … a k ), where k is also fixed. There are evidently n k such words in all.... hiện toàn bộ
Bireflectionality in Classical GroupsCanadian Journal of Mathematics - Tập 29 Số 6 - Trang 1157-1162 - 1977
Erich W. Ellers
The motion groups of the real Euclidean plane and of the elliptic plane, the
group of projectivities of a line, the projective general linear group PGL2(K),
some orthogonal groups O3(K, Q) with char K = 2 (see [8]), are all
bireflectional (zweispiegelig). There can be no doubt that bireflectional groups
are of prime importance in any theory of groups that are generated by
involutions. A brief look... hiện toàn bộ
On Transformation and Oscillation of Linear Differential SystemCanadian Journal of Mathematics - Tập 29 Số 2 - Trang 392-399 - 1977
Donald F. St. Mary
In this paper we study second order linear differential systems. We examine the
relationship between oscillation of n-dimensional systems and certain associated
n-dimensional systems, where m ≧ n. Several theorems are presented which unify
and encompass in the linear case a number of results from the literature. In
particular, we present a transformation which extends an oscillation theorem due
to... hiện toàn bộ
Oscillation Criteria for Matrix Differential EquationsCanadian Journal of Mathematics - Tập 19 - Trang 184-199 - 1967
H. C. Howard
We shall be concerned at first with some properties of the solutions of the
matrix differential equation1.1whereis an n × n symmetric matrix whose elements
are continuous real-valued functions for 0 < x < ∞, and Y(x) = (yij(x)), Y″(x) =
(y″ ij(x)) are n × n matrices. It is clear such equations possess solutions for
0 < x < ∞, since one can reduce them to a first-order system and then apply
known e... hiện toàn bộ
An integral Representation of a 10ϕ9 and Continuous Bi-Orthogonal 10ϕ9 Rational FunctionsCanadian Journal of Mathematics - Tập 38 Số 3 - Trang 605-618 - 1986
Mizan Rahman
1. Introduction. One of the most remarkable q-extensions of the classical beta
integral was recently introduced by Askey and Wilson [1](1.1)where |q| < 1 and
the pairwise products of {a, b, c, d} as a multiset do not belong to the set
{qj, j = 0, – 1, – 2, …}. The contour C is the unit circle described in the
positive direction, but with suitable deformations to separate the sequences of
poles con... hiện toàn bộ
On Indefinite Ternary Quadratic FormsCanadian Journal of Mathematics - Tập 8 - Trang 592-608 - 1956
Barrie Jones, G. L. Watson
1, Introduction. The first systematic study of equivalence of indefinite ternary
quadratic forms seems to be that of A. Meyer (10) (see also Bachmann (1)). By
methods which are often obscure he showed that the number of classes in a genus
is a power of 2, the exact power depending on certain quadratic characters
associated with the form.