نتایج جستجو برای: rectifiable space

تعداد نتایج: 494571  

2008
XAVIER TOLSA

In this paper we study some questions in connection with uniform rectifiability and the L boundedness of Calderón-Zygmund operators. We show that uniform rectifiability can be characterized in terms of some new adimensional coefficients which are related to the Jones’ β numbers. We also use these new coefficients to prove that n-dimensional CalderónZygmund operators with odd kernel of type C2 a...

1997
Shuang Zhang SHUANG ZHANG

We prove that any two homotopic projections in certain C*-algebras can be connected by a rectifiable path of projections whose length is bounded by a universal constant. In comparison, N.C. Phillips (1992) proved that there are C*algebras in which such a universal constant does not exist. Our techniques are to estimate the number of symmetries needed to conjugate any two homotopic projections a...

2009
JOHN GARNETT ROWAN KILLIP RAANAN SCHUL

By reparametrization, one may assume that γ is Lipschitz with constant equal to length(γ). We will also make use of the following simple (and well-known) criterion: a compact set Γ is the image of a rectifiable curve if and only if it is connected and H(Γ) < ∞. Indeed, one may choose γ so that length(γ) ≤ CH(Γ); see, for example, [1, 2]. Here and below, H denotes the one-dimensional Hausdorff m...

2006
G. CITTI M. Manfredini

In this paper, we study the notion of regular surface in the Carnot–Carathéodory spaces and we prove the implicit function theorem in this setting. We fix at every point of R a subset of the tangent space, called horizontal tangent plane, and we assume that it has a basis X1, . . . , Xm of C∞ vector fields satisfying the Hörmander condition of hypoellipticity, (see [16]). This choice induces a ...

2006
Brigitte Forster

We give direct and inverse approximation theorems for Dirichlet series in Smirnov spaces over convex polygons. We estimate the degree of convergence and the regularity of the functions with moduli of arbitrary order k. Moreover, we consider the influence of differentiability conditions on the rate of approximation and vice versa. This work extends results by Yu. I. Mel’nik and gives an example ...

2008
David Constantine Jean-François Lafont

In a compact geodesic metric space of topological dimension one, the minimal length of a loop in a free homotopy class is well-defined, and provides a function l : π1(X) −→ R+ ∪ ∞ (the value ∞ being assigned to loops which are not freely homotopic to any rectifiable loops). This function is the marked length spectrum. We introduce a subset Conv(X), which is the union of all non-constant minimal...

2008
Gian Paolo Leonardi Simon Masnou

The aim of this paper is to investigate whether, given two rectifiable k-varifolds in R with locally bounded first variations and integer-valued multiplicities, their mean curvatures coincide H-almost everywhere on the intersection of the supports of their weight measures. This so-called locality property, which is well-known for classical C2 surfaces, is far from being obvious in the context o...

1999
Fang-Hua Lin FANG-HUA LIN

For stationary harmonic maps between Riemannian manifolds, we provide a necessary and sufficient condition for the uniform interior and boundary gradient estimates in terms of the total energy of maps. We also show that if analytic target manifolds do not carry any harmonic S2, then the singular sets of stationary maps are m ≤ n− 4 rectifiable. Both of these results follow from a general analys...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید