Recursos de colección
Project Euclid (Hosted at Cornell University Library) (192.979 recursos)
African Diaspora Journal of Mathematics
African Diaspora Journal of Mathematics
Diaz, Jesus Ildefonso; Meyer, Yves
New Poisson summation formulae have been recently discovered by Nir Lev and
Alexander Olevskii since 2013. But some other examples were concealed in an old
paper by Andrew Guinand dating from 1959. This was observed by the second author
in 2016. In the present contribution a third approach is proposed. Guinand's
work follows from some simple observations on solutions of the wave equation on
the three dimensional torus. If the initial velocity is a Dirac mass at the
origin, the solution is Guinand's distribution. Using this new approach one can
construct a large family of initial velocities which give rise to crystalline
measures generalizing Guinand's solution.
Kourouma, Moussa
Let $(M,g)$ and $(N,h)$ be compact Riemannian manifolds, where $(N,h)$ is
symmetric, $v\in W^{1,2}((M,g),(N,h))$, and $\tau $ is the tension field for
mappings from $(M,g)$ into $(N,h)$. We consider the nonlinear eigenvalue problem
$\tau (u)-\lambda \exp _{u}^{-1}v=0$, for $u$ $\in W^{1,2}(M,N)$ such that
$u_{\left\vert \partial M\right. }=v_{\left\vert \partial M\right.}$, and
$\lambda \in \mathbb{R}$. We prove, under some assumptions, that the set of all
$\lambda $, such that there exists a solution $(u,\lambda )$ of this problem and
a non trivial Jacobi field $V$ along $u$, is contained in $\mathbb{R}_{+}$, is
countable, and has no accumulation point in $\mathbb{R}$. This result
generalizes a well known one about the spectrum of...
Huang, Shuliang; Rehman, Nadeem ur
Let $M$ be a prime $\Gamma-$ring, $I$ a nonzero ideal, $\theta$ an automorphism
and $d$ a $\theta-$derivation of $M$. In this article we have proved the
following result: (1) If $d([x,y]_{\alpha})=\pm([x,y]_{\alpha})$ or $d((x\circ
y)_{\alpha})=\pm((x\circ y)_{\alpha})$ for $x, y\in I; \alpha\in \Gamma$, then
$M$ is commutative. (2) Under the hypothesis $d\theta=\theta d$ and $Char
M\neq2$, if $(d(x)\circ d(y))_{\alpha}=0$ or $[d(x),d(y)]_{\alpha}=0$ for all
$x, y\in I;\alpha\in \Gamma$, then $M$ is commutative. (3) If $d$ acts as a
homomorphism or an anti-homomorphism on $I$, then $d=0$ or $M$ is commutative.
Moreover, an example is given to demonstrate that the primeness imposed on the
hypothesis of the various results is essential.
Goli, Charles Etienne; Adje, Assohoun
We study the existence of solutions of the quasilinear equation
$$(D(u(t))\phi(u'(t)))'=f(t,u(t),u'(t)),\qquad a.e. \;\;t\in [0,T],$$ subject to
nonlinear Neumann-Steklov boundary conditions on $[0,T]$, where $\phi:
(-a,a)\rightarrow \mathbb{R}$ (for $0 < a < \infty$) is an increasing
homeomorphism such that $\phi(0)=0$, $f:[0,T]\times\mathbb{R}^{2} \rightarrow
\mathbb{R}$ a $L^1$-Carathéodory function, $D$ : $\mathbb{R}\longrightarrow
(0,\infty)$ is a continuous function. Using topological methods, we obtain
existence and multiplicity results.
Diop, C.; Sow, T. M. M.; Djitte, N.; Chidume, C. E.
Let $E$ be a Banach space either $l_p$ or $L_p$ or $W^{m,p}$, $1 < p <
\infty$, with dual $E^*$, and let $F :E\mapsto E^*$, $K: E^*\mapsto E $ be
Lipschitz and strongly monotone mappings with $D(K)=R(F)=E^*$. Assume that the
Hammerstein equation $u+KFu=0$ has a unique solution $\bar u$. For given $u_1\in
E$ and $v_1\in E^*$, let $\{u_n\}$ and $\{v_n\}$ be sequences generated
iteratively by: $u_{n+1} = J^{-1}(Ju_n -\lambda(Fu_n-v_n)),\,\,\,n\geq 1$ and
$v_{n+1} = J(J^{-1}v_n-\lambda(Kv_n+u_n)),\,\,\,n\geq 1$, where $J$ is the
duality mapping from $E$ into $E^*$ and $\lambda$ is a positive real number in
$(0,1)$ satisfying suitable conditions. Then it is proved that the sequence
$\{u_n\}$ converges strongly to $\bar...
Signing, Lazarus
This paper is devoted to the homogenization of Shrödinger type equations with periodically oscillating coefficients of the diffusion term, and a rapidly oscillating periodic potential. One convergence theorem is proved and we derive the macroscopic homogenized model. Our approach is the well known two-scale convergence method.
Kinfack Jeutsa, A.; Njifenjou, A.; Nganhou, J.
Our purpose in this paper is to present a theoretical analysis of the Discrete Duality Finite Volume method (DDFV method) for 2D-flow problems in anisotropic heterogeneous porous media with full Neumann boundary conditions. We start with the derivation of the discrete problem, and then we give a result of existence and uniqueness of a solution for that problem. Their theoretical properties, namely stability and error estimates in discrete energy norms and $L^2$-norm are investigated. Numerical tests are provided.
Zabsonre, Issa; Toure, Hamidou
The aim of this work is to present new approach to study weighted pseudo almost periodic and automorphic functions using the measure theory. We present a new concept of weighted ergodic functions which is more general than the classical one. Then we establish many interesting results on the functional space of such functions. We study the existence and uniqueness of $(\mu,\nu)$-pseudo almost periodic and automorphic solutions of class $r$ for some neutral partial functional differential equations in a Banach space when the delay is distributed using the spectral decomposition of the phase space developed in Adimy and co-authors. Here we...
Gaparayi, Donatien; Issa, A. Nourou
A Hom-Lie-Yamaguti algebra, whose ternary operation expresses through its binary
one in a specific way, is a multiplicative Hom-Malcev algebra. Any
multiplicative Hom-Malcev algebra over a field of characteristic zero has a
natural Hom-Lie-Yamaguti structure.
Biyogmam, Guy Roger
In this paper, we construct several indefinite orthogonal invariants in terms of
balanced tensors and use Lodder's structure theorem to provide the Leibniz
(co)homology of the indefinite orthogonal Lie algebra in terms of these
invariants.
Sagna, Yaya; Sow, Ahmadou Bamba
This paper is devoted to solve a multidimensional backward stochastic
differential equation with jumps in finite time horizon. Under weak monotonicity
condition on the generator and by means of suitable sequences, we prove
existence and uniqueness of solution.
Villamor, Enrique; Olivares, Pablo
In this short note, we present a new version of the Central Limit Theorem whose
proof is based on Levy's characterization of Brownian motion. The method in the
proof may allow to extend the result to a more general context, e.g. to averaged
sums of properly compensated dependent random variables.
Yamaguchi, Toshihiro
We define a rational homotopy invariant, the rational pairing rank $v_0(f)$ of a
map $f:X\to Y$, which is a natural generalization of the rational pairing rank
$v_0(X)$ of a space $X$ [16]. It is upper-bounded by the rational LS-category
$cat_0(f)$ and lower-bounded by an invariant $g_0(f)$ related to the rank of
Gottlieb group. Also it has a good estimate for a fibration $X\overset{j}{\to}
E\overset{p}{\to} Y$ such as $v_0(E)\leq v_0(j) +v_0(p)\leq v_0(X) +v_0(Y)$.
Mir, Abdullah; Mboup, Mamadou
In this paper, we present some inequalities for the growth and derivatives of a
polynomial with zeros outside a circle of arbitrary radius $k\gt 0$. Our results
provide improvements and generalizations of some well known polynomial
inequalities.
Mahaman, Bazanfaré; Mboup, Mamadou
In this paper, we study the topology of complete noncompact Riemannian manifolds
with asymptotically nonnegative Ricci curvature. We show that a complete
noncompact manifold $M$ with asymptotically nonnegative Ricci curvature and
sectional curvature $K(x)\ge \frac{C}{d_{p}(x)^{\alpha}}$ is diffeomorphic to
the Euclidean space $\mathbb{R}^n$ under some conditions on the density of rays
starting from the base point $p$ or on the volume growth of geodesic balls in
$M$.
Kourouma, Moussa
We prove that the mean value (for some measure $\mu =\chi dx$ with $\chi \geq
0,dx=$ Riemannian measure) of the squared norm of the gradient of the unitary
direction of a Jacobi field along an eigenmapping $v$ (associated to an
eigenvalue $\lambda \geq 0$) of the tension field, for mappings from a compact
Riemannian manifold $(M,g)$ into a symmetric Riemannian manifold $(N,h)$ of
positive sectional curvature, is smaller than $c\lambda $, where $c>0$
depends only on the diameter and upper and lower curvature bounds of $(N,h)$.
For negative $\lambda $, we prove that there is no nonvanishing Jacobi field
along the eigenmappings, under the same assumptions on $(M,g)$...
Ostadhadi-Dehkordi, S.; Davvaz, B.
A hypermodule is a multivalued algebraic system satisfying the module like
axioms. In this paper, we construct quotient hypermodule. Let $M$ be a
hypermodule, $N$ be a subhypermodule of $M$ and $I$ be a hyperideal of $R$.
Then, $[M:N^{\ast}]$ is $R$-hypermodule and $[R:I^{\ast}]$-hypermodule, and
prove that when $N$ is normal subhypemodule, $[M:N^{\ast}]$ is a
$[R:I^{\ast}]$-module. Hence, the quotient hypermodules considered by Anvarieh
and Davvaz are modules.
Dragomir, S. S.; Seo, Y.
In this paper we obtain some operator inequalities for functions defined by power
series with complex coefficients and, more specifically, with nonnegative
coefficients. In order to obtain these inequalities the classical Wielandt and
some reverses of the Schwarz inequality for vectors in inner product spaces are
utilized. Natural applications for some elementary functions of interest are
also provided.
Naika, M. S. Mahadeva; Suman, N. P.; Chandankumar, S.
In this paper, we establish several new Schläfli-type mixed modular equations of
composite degrees. These equations are analogous to those recorded by Ramanujan
in his second notebook. As an application, we establish several new explicit
values for the Ramanujan-Weber class invariant $G_{n}$ for $n=12, 48, 51, 57,
3/4, 3/16, 3/17$ and $3/19$.
Liu, Yuji
In this article, we establish some existence results for solutions of a initial
value problem of a nonlinear fractional differential system on half line
involving the sequential Riemann-Liouville fractional derivatives. Our analysis
relies on the Schauder fixed point theorem. An efficiency example is presented
to illustrate the main theorem. As far as the author knows, the present work is
perhaps the first one that deals with such kind of initial value problems for
fractional differential systems on half line.