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Now showing items 1-10 of 25

#### Fixed points and approximate fixed points in product spaces [Article]

(The Mathematical Society of the Republic of China, 2001-06)

The paper deals with the general theme of what is known about the existence of fixed points and approximate fixed points for mappings which satisfy geometric conditions in product spaces. In particular it is shown that ...

#### The fixed-point property in Banach spaces containing a copy of c0 [Article]

(Hindawi, 2003)

We prove that every Banach space containing an isomorphic copy of c0 fails to have the fixed-point property for asymptotically nonexpansive mappings with respect to some locally convex topology which is coarser than the ...

#### Riesz's theorem for orthogonal matrix polynomials [Article]

(Springer, 1999-01)

We describe the image through the Stieltjes transform of the set of solutions V of a matrix moment problem. We extend Riesz's theorem to the matrix setting, proving that those matrices of measures of V for which the matrix ...

#### On the modification of classical orthogonal polynomials: the symmetric case [Article]

(Springer, 1998-03)

We consider the modifcations of the monic Hermite and Gegenbauer polynomials via the addition of one point mass at the origin. Some properties of the resulting polynomials are studied: three-term recurrence relation, ...

#### Potential operators, maximal functions, and generalizations of A∞ [Article]

(Springer, 2003-08)

We derive weighted norm estimates which relate integral operators of potential type (fractional integrals) to corresponding maximal operators (fractional maximal operators). We also derive norm estimates for the maximal ...

#### Uniformly Lipschitzian mappings in modular function spaces [Article]

(Elsevier, 2001-10)

Let ρ be a convex modular function satisfying a ∆2-type condition and Lρ the corresponding modular space. Assume that C is a ρ-bounded and ρ-a.e compact subset of Lρ and T : C → C is a k-uniformly Lipschitzian mapping. ...

#### Structure of the fixed point set and common fixed points of asymptotically nonexpansive mappings [Article]

(American Mathematical Society, 2001)

Let X be a Banach space, C a weakly compact convex subset of X and T : C → C an asymptotically nonexpansive mapping. Under the usual assumptions on X which assure the existence of fixed point for T, we prove that the set ...

#### Two-weight, weak-type norm inequalities for singular integral operators [Article]

(International Press, 1999)

We give a sufficient condition for singular integral operators and, more generally, Calder´on-Zygmund operators to satisfy the weak (p, p) inequality u({x ∈ R n : |T f(x)| > t}) ≤ C / tp Z Rn |f|p v dx, 1 < p < ∞. Our ...

#### Endpoint estimates for commutators of singular integral operators [Article]

(Elsevier, 1995-02-15)

We prove endpoint estimates for commutatotrs of singular integrals with BMO functions. We first show that they satisfy L(log L) type inequalities and then that there is a Hardy space type estimate where the usual atomic ...