arXiv subjects
Publications and source records attributed to Mohammad Daher.
Let X be a complex Banach space, in this work we characterize the property of Frechet differentiability for the dual space of X. In the following, we show that if the dual space of X is Gateaux differentiable, then the dual space of Lp(X) has the same property for all p betwwen one and infiniy
Dans ce travail, on montre que $(M(\mathbb{T}),c_0(\mathbb{Z}))_\theta = (L^1,c_0(\mathbb{Z}))_\theta$, $0<\theta <1$. Dans la suite on montre pour le couple d'interpolation $(C_0,C_1)$ trouv\'e par Garling-Smith qu'il existe un isomorphisme $U_\theta: (C_0,C_0+C_1)_{\theta ,p}\rightarrow (C_1,C_0+C_1)_{\theta, p}$ (resp. $U_\theta : (C_0,C_0+C_1)_\theta \rightarrow (C_1,C_0+C_1)_\theta)$ tel que sa restriction \`a $C_{\theta, p}$ (resp. \`a $C_\theta)$ est un isomorphisme : $C_{\theta, p} \rightarrow C_{1-\theta, p}$ (resp. $C_\theta \rightarrow C_{1-\theta })$. -- In this work we show that $(M(\mathbb{T}),c_0(\mathbb{Z}))_\theta = (L^1,c_0(\mathbb{Z}))_\theta$, $0<\theta <1.$ In the following we show for the interpolation couple found by Garling-Smith that there exists an isomorphism $U_\theta: (C_0,C_0+C_1)_{\theta ,p}\rightarrow (C_1,C_0+C_1)_{\theta, p}$ (resp. $U_\theta : (C_0,C_0+C_1)_\theta \rightarrow (C_1,C_0+C_1)_\theta)$ such that its restriction to $C_{\theta ,p}$ (resp. to $C_\theta)$ is an isomorphism : $C_{\theta, p} \rightarrow C_{1-\theta, p}$ (resp. $C_\theta \rightarrow C_{1-\theta })$.
In the first part of this work, we study the absolutely continuous operators which are defined on fuction spaces with wide sense. In the second part, we show some results concerning the absoltely continuous operators when the function spaces (with wide sense) are interpolation spaces.
Let $(\Omega_1, \mathcal{F}_1, \mu_1)$, $(\Omega_2, \mathcal{F}_2, \mu_2)$ be two probabilty spaces, $1\leq p\leq +\infty$ and $X$ a Banach space. In this work we show that $L^p(\mu_1, X)$, $VB^p (\mu_1,X),$ $cabv(\mu_{1},X)$ are isomorphic to $L^p(\mu_2, X),$ $VB^p(\mu_2, X)$, $cabc(\mu_2, X)$ respectively, if $L^1(\mu_1)$ is strongly isomorphic to $L^1(\mu_2)$.
Let X,Y be two Banach spaces ; in the first part of this work, we show that K(X,Y) contains a complemented copy of c0 if Y contains a copy of c0 and each bounded sequence in Y has a subsequece which is w* convergente. Afterward we obtain some results of M.Feder and G.Emmanuele: Finally in this part we study the relation between the existence of projection from L(X,Y) on K(X,Y) and the existence of pro- jection from K(X,Y ) on K(X,Y) if Y has the approximation property. In the second part we study the Radon-Nikodym property in L(X,Y):
In this paper, we show that there are a totally ordered compact K separable (K is Rosenthal compact set), a Hausdorff topology T' on C(K) and two closed subspaces Y1, Y2 of (C(K); Tp) such that (C(K);T') is not universally measurable, (C(K),Tp) = (Y1,Tp) + (Y2,Tp);(Y1,Tp) is isomorphic to (Y2,Tp), (Yj ,Tp) = (Yj,T'), j=1,2; and Bor((C(K)XC(K),T'XT')) is not equal to Bor(C(K)),T'))XC(K)),T')) this is the main result of this work. We start this work to construct totally ordered non metrisable compact sets K(E) from a reference set E which is totally ordered, and from a positive Borel measure on E satisfying some reasonable assumptions.
Let $(A_0, A_1)$ be an interpolation couple, and let $B_j$ be the closure of $A_0^\ast \cap A_1^\ast$ in $A_j^\ast$, $j = 0, 1$. For every $θ\in \, ]0, 1[$, there exists a natural one to one contraction $R^θ: A^θ\rightarrow (B_0^\ast, B_1^\ast)^θ$. For some $β\in \, ]0, 1[$, the closure of $R^β(A^β)$ in $(B_0^\ast, B_1^\ast)^β$ is supposed to be weakly LUR. Then $A^θ= A_θ$ for every $θ\in \, ]0, 1[$.