arXiv subjects

Justin Feuto

Publications and source records attributed to Justin Feuto.

24 records · Page 2Linked to original sources

arXiv2009

Integrable fractional mean functions on spaces of homogeneous type

The class of Banach spaces $(L^{q},L^{p}) ^α(X,d,μ)$, $1\leq q\leq α\leq p\leq \infty ,$ introduced in \cite{F1} in connection with the study of the continuity of the fractional maximal operator of Hardy-Littlewood and of the Fourier transformation in the case $% X=\mathbb{R}^{n}$ and $μ$ is the Lebesgue measure, was generalized in \cite{FFK} to the setting of homogeneous groups. We generalize it here to spaces of homogeneous type and we prove that the results obtained in \cite{FFK} such as relations between these spaces and Lebesgue spaces, weak Lebesgue and Morrey spaces, remain true.

math.CA↗

arXiv2009

Endpoint for the div-curl lemma in Hardy spaces

We give a div-curl type lemma for the wedge product of closed differential forms on R^n when they have coefficients respectively in a Hardy space and L^infinity or BMO. In this last case, the wedge product belongs to an appropriate Hardy-Orlicz space.

math.CA↗

arXiv2009

Products of Functions in Hardy and Lipschitz or Bmo Spaces

We define as a distribution the product of a function (or distribution) h in some Hardy space Hp with a function b in the dual space of Hp. Moreover, we prove that the product bxh may be written as the sum of an integrable function with a distribution that belongs to some Hardy-Orlicz space, or to the same Hardy space Hp, depending on the values of p.

math.CA↗

arXiv2009

Products of functions in $\BMO$ and $\H^{1}$ spaces on spaces of homogeneous type

We give an extension to certain \textit{RD-space} $\X$, i.e space of homogeneous type in the sense of Coifman and Weiss, which has the reverse doubling property, of the definition and various properties of the product of functions in $\BMO(\X)$ and $\H^{1}(\X)$, and functions in Lipschitz space $Λ_{\frac{1}{p}-1}(\X)$ and $\H^{p}(\X)$ for $p\in(\frac{\n}{\n+θ},1]$, where $\n$ and $θ$ denote respectively the "dimension" and the order of $\X$

math.CA↗

arXiv2009

Weighted norms inequalities for a maximal operator in some subspace of amalgams

We give weighted norm inequalities for the maximal fractional operator $ \mathcal M_{q,β}$ of Hardy-Littlewood and the fractional integral $I_γ$. These inequalities are established between $(L^{q},L^{p}) ^α(X,d,μ)$ spaces (which are super spaces of Lebesgue spaces $L^α(X,d,μ)$, and subspaces of amalgams $(L^{q},L^{p})(X,d,μ)$) and in the setting of space of homogeneous type $(X,d,μ)$. The conditions on the weights are stated in terms of Orlicz norm.

math.CA↗

arXiv2008

Espaces de fonctions à moyenne fractionnaire intégrable sur les groupes localement compacts

Let $G$ be a locally compact group which is $σ$-compact, endowed with a left Haar measure $λ.$ Denote by $e$ the unit element of $G$, and by $B$ an open relatively compact and symmetric neighbourhood of $e$. For every $(p,q) $ belonging to $[ 1 ; +\infty ] ^{2}$, we give an equivalent and a priori more manageable definition of the Banach space $L_{(q,p)}^π(G),$ defined by R. C. Busby and H. A. Smith in \cite% {1}. In the case $G$ is a group of homogeneous type, we look at the subspaces $(L^{q},L^{p}) ^α(G)$ of the space $% L_{(q,p)}^π(G)$. Theses subspaces are extensions to non abelian groups of the spaces of functions with integrable mean, defined by I. Fofana in \cite{2}. Finally we show that $L^{α,+\infty}(G)$ is a complex subspace of $(L^{q},L^{p}) ^α(G)$.

math.CA↗