Canadian Mathematical Bulletin
SCIE-ISI SCOPUS (1996-2025)
1496-4287
0008-4395
Canada
Cơ quản chủ quản: CAMBRIDGE UNIV PRESS , Canadian Mathematical Society
Lĩnh vực:
Mathematics (miscellaneous)
Các bài báo tiêu biểu
A Generalization of a Fixed Point Theorem of Reich
Tập 16 Số 2 - Trang 201-206 - 1973
The following theorem is the principal result of this paper.Let (M, d) be a
metric space and T a self-mapping of M satisfying the condition for x,y ∊
M1where a, b, c, e,f are nonnegative and we set α=a+b+c+e+f.
Beatty Sequences, Continued Fractions, and Certain Shift Operators
Tập 19 Số 4 - Trang 473-482 - 1976
AbstractLet θ = θ(k) be the positive root of θ2 + (k-2)θ-k = 0. Let f(n) = [(n +
l)θ]-[nθ] for positive integers n, where [x] denotes the greatest integer in x.
Then the elements of the infinite sequence (f(l), f(2), f(3),…) can be rapidly
generated from the finite sequence (f(l), f(2),…,f(k)) by means of certain shift
operators. For k = 1 we can generate (the characteristic function of) the
seque...
B-Stable Ideals in the Nilradical of a Borel Subalgebra
Tập 48 Số 3 - Trang 460-472 - 2005
AbstractWe count the number of strictly positive B-stable ideals in the
nilradical of a Borel subalgebra and prove that the minimal roots of any
B-stable ideal are conjugate by an element of the Weyl group to a subset of the
simple roots. We also count the number of ideals whose minimal roots are
conjugate to a fixed subset of simple roots.
Stability of Almost Periodic Nicholson’s Blowflies Model Involving Patch Structure and Mortality Terms
Tập 63 Số 2 - Trang 405-422 - 2020
AbstractTaking into account the effects of patch structure and nonlinear
density-dependent mortality terms, we explore a class of almost periodic
Nicholson’s blowflies model in this paper. Employing the Lyapunov function
method and differential inequality technique, some novel assertions are
developed to guarantee the existence and exponential stability of positive
almost periodic solutions for th...
Determination of [nθ] by its Sequence of*Differences
Tập 21 Số 4 - Trang 441-446 - 1978
AbstractFor any real numberθletwhere [x] denotes the greatest integer not
exceedingx.A method is given for computingfθfrom its first few terms. A similar
method is given for computing the characteristic functiongθ(n)of[nθ]. The given
methods converge rapidly, and generalize previous results of Bernoulli, Markorf,
and Stolarsky. Note that either of the sequencesfθand gθdetermines the
sequence[nθ] (...
Rings all of Whose Pierce Stalks are Local
Tập 22 Số 2 - Trang 159-164 - 1979
The aim of this paper is to give a number of characterizations of the rings of
the title. In particular, these turn out to be precisely those exchange rings
whose idempotents are all central. They are also those rings in which every
element is the sum of a unit and a central idempotent.
Imaginary Verma Modules for Affine Lie Algebras
Tập 37 Số 2 - Trang 213-218 - 1994
AbstractWe study a class of irreducible modules for Affine Lie algebras which
possess weight spaces of both finite and infinite dimensions. These modules
appear as the quotients of "imaginary Verma modules" induced from the "imaginary
Borel subalgebra".
Obstructions to 𝒵-Stability for Unital Simple C*-Algebras
Tập 43 Số 4 - Trang 418-426 - 2000
AbstractLet 𝒵 be the unital simple nuclear infinite dimensional C*-algebra
which has the same Elliott invariant as ℂ, introduced in [9]. A C*-algebra is
called 𝒵-stable if A ≅ A ⊗ 𝒵. In this note we give some necessary conditions
for a unital simple C*-algebra to be 𝒵-stable.
A Note on a Theorem of Ky Fan
Tập 22 Số 4 - Trang 513-515 - 1979
Fan ([2, Theorem 2]) has proved the following theorem:Let K be a nonempty
compact convex set in a normed linear space X. For any continuous map f from K
into X, there exists a point u∈K such thatIn this note, we prove that the above
theorem is true for a continuous condensing map defined on a closed ball in a
Banach space. We also prove that it is true for a continuous condensing map
defined on a ...
A Characterization of the Quadratic Irrationals
Tập 34 Số 1 - Trang 36-41 - 1991
AbstractLet α be a positive irrational real number, and let fα (n) = [(n + l)α]
— [nα] — [α],n > 1, where [x] denotes the greatest integer not exceeding x. It
is shown that the sequence fα has a certain 'substitution property' if and only
if α is the root of a quadratic equation over the rationals.