Some Notes on Endpoint Estimates for Pseudo-differential OperatorsMediterranean Journal of Mathematics - Tập 19 - Trang 1-14 - 2022
Jingwei Guo, Xiangrong Zhu
We study the pseudo-differential operator $$\begin{aligned} T_a f\left( x\right)
=\int _{\mathbb {R}^n}e^{ix\cdot \xi }a\left( x,\xi \right) \widehat{f}\left(
\xi \right) \,\text {d}\xi , \end{aligned}$$ where the symbol a is in the
Hörmander class $$S^{m}_{\rho ,1}$$ or more generally in the rough Hörmander
class $$L^{\infty }S^{m}_{\rho }$$ with $$m\in \mathbb {R}$$ and $$\rho \in
[0,1]$$ . It i... hiện toàn bộ
A-Spectral Permanence Property for $$C^*$$ -AlgebrasMediterranean Journal of Mathematics - Tập 21 - Trang 1-17 - 2024
Mohamed Mabrouk, Ali Zamani
For a positive element A of a $$C^*$$ -algebra $$\mathfrak {A}$$ , let $${\Vert
X\Vert }_{A}$$ denote the A-operator semi-norm of $$X\in \mathfrak {A}$$ . In
this paper, we aim to introduce and study the notion of A-spectrum for X, such
that $${\Vert X\Vert }_{A}<\infty $$ . In particular, when A is well supported,
we establish an A-spectral permanence property for $$C^*$$ -algebras.... hiện toàn bộ
The Frobenius Problem for Generalized Repunit Numerical SemigroupsMediterranean Journal of Mathematics - Tập 20 - Trang 1-18 - 2022
Manuel B. Branco, Isabel Colaço, Ignacio Ojeda
In this paper, we introduce and study the numerical semigroups generated by
$$\{a_1, a_2, \ldots \} \subset {\mathbb {N}}$$ such that $$a_1$$ is the repunit
number in base $$b > 1$$ of length $$n > 1$$ and $$a_i - a_{i-1} = a\,
b^{i-2},$$ for every $$i \ge 2$$ , where a is a positive integer relatively
prime with $$a_1$$ . These numerical semigroups generalize the repunit numerical
semigroups amon... hiện toàn bộ
Triviality and Rigidity of Almost Riemann SolitonsMediterranean Journal of Mathematics - - 2024
Amalendu Ghosh
In this paper, we study some triviality and rigidity results of Riemann soliton.
First, we derive some sufficient conditions for which an almost Riemann soliton
is trivial. In particular, we prove that any compact almost Riemann soliton with
constant scalar curvature has constant sectional curvature. Next, we prove some
rigidity results for gradient Riemann solitons. Precisely, we prove that a
non... hiện toàn bộ
Existence of Solutions to Fractional Elliptic Equation with the Hardy Potential and Concave–Convex NonlinearitiesMediterranean Journal of Mathematics - Tập 20 - Trang 1-16 - 2022
Xiangrui Li, Shuibo Huang, Qiaoyu Tian
In this paper, by a new variational principle established by Moameni, we
establish the existence of solutions to the following fractional elliptic
equation with the Hardy potential and concave–convex nonlinearities,
$$\begin{aligned} {\left\{ \begin{array}{ll} (-\Delta )^{s}u(x)- \lambda
\frac{u(x)}{|x|^{2s}}=u(x)^{p-1}+\mu u(x)^{q-1}, &{}{} x\in \Omega ,\\
~~~~~~~~~~~~~~~~~~~~~~~~~u(x)>0, &{}{}x\... hiện toàn bộ
Sharp Hardy Inequalities in Star-shaped Domains with Double Singular KernelsMediterranean Journal of Mathematics - Tập 14 - Trang 1-13 - 2016
Alexander Fabricant, Nikolai Kutev, Tsviatko Rangelov
Improved Hardy inequality with double singular kernel in bounded, star-shaped
domains $$\Omega \subset R^n$$ is proved. The case of singularity at an interior
point and on the boundary of the domain is considered. The Hardy constant is
optimal and the inequality is sharp due to the additional term.... hiện toàn bộ
The Multipoint Initial–Final Value Condition for the Hoff Equations on Geometrical Graph in Spaces of $$\mathbf{K}$$ -“noises”Mediterranean Journal of Mathematics - Tập 19 - Trang 1-19 - 2022
Angelo Favini, Sophiya A. Zagrebina, Georgy A. Sviridyuk
We consider a linear stochastic Sobolev type equation with relatively p-bounded
operator and formulate a multipoint initial–final value condition for the
equation. In addition, we prove a theorem on the existence of a unique solution
to this problem in the space of $$\mathbf{K}$$ -“noises”. Abstract results are
used to study a specific multipoint initial–final value problem for linear
stochastic H... hiện toàn bộ