共查询到20条相似文献,搜索用时 46 毫秒
1.
LetW be an open Riemann surface and
ap-sheeted (1<p<∞) unlimited covering surface ofW. Denote by Δ1 (resp.,
) the minimal Martin boundary ofW (resp.,
). For ζ ∈ Δ, let
ζ be the (cardinal) number of the set of pionts
which lie over ζ and
the class of open connected subsetsM ofW such thatM∪{ζ} is a minimal fine neighborhood of ζ. Our main result is the following:
, where
is the number of components of π-1
M and π is the projection of
ontoW. Moreover, some applications of the above results are discussed whenW is the unit disc. 相似文献
2.
Peter Raith 《Journal d'Analyse Mathématique》1999,78(1):117-142
Assume thatX is a finite union of closed intervals and consider aC
1-mapX→ℝ for which {c∈X: T′c=0} is finite. Set
. Fix ann ∈ ℕ. For ε>0, theC
1-map
is called an ε-perturbation ofT if
is a piecewise monotonic map with at mostn intervals of monotonicity and
is ε-close toT in theC
1-topology. The influence of small perturbations ofT on the dynamical system (R(T),T) is investigated. Under a certain condition on the continuous functionf:X → ℝ, the topological pressure is lower semi-continuous. Furthermore, the topological pressure is upper semi-continuous for
every continuous functionf:X → ℝ. If (R(T),T) has positive topological entropy and a unique measure μ of maximal entropy, then every sufficiently small perturbation
ofT has a unique measure
of maximal entropy, and the map
is continuous atT in the weak star-topology. 相似文献
3.
Katsunori Iwasaki 《Journal d'Analyse Mathématique》1997,72(1):279-298
LetP be ann-dimensional regular simplex in ℝn centered at the origin, and let P(k) be thek-skeleton ofP fork = 0, 1,…,n. Then the set
of all continuous functions in ℝn satisfying the mean value property with respect to P(k) forms a finite-dimensional linear space of harmonic polynomials. In this paper the function space
is explicitly determined by group theoretic and combinatorial arguments for symmetric polynomials. 相似文献
4.
Andrew J. Sommese 《Milan Journal of Mathematics》1997,67(1):49-75
Let
be an algebraic submanifold of complex projective space ℙ
N
. Assume thatn:=dim
and let
denote the restriction of the hyperplane section bundle
to
. The meromorphic map
associated to
fork≥1 ties together the pluricanonical maps of the surface sections of
. Known results show that the behavior of
is far better than one would expect from experience with the pluricanonical mappings of algebraic surfaces. In this article
we discuss the known results on the structure of the mappings
and describe the open problems.
Conferenza tenuta il 5 giugno 1997 相似文献
5.
Fabio Vlacci 《Journal d'Analyse Mathématique》1998,75(1):51-66
We introduce the notion of pointwise regularity (
) of Colombeau’s generalized functions and give comparison theorems between
regularity,
- andC
∞-regularity. We also define the notion of a pointwise wave front set and establish a theorem concerning the effect of a linear
generalized partial differential operator on such a wave front. 相似文献
6.
We obtain a set of necessary and sufficient conditions for
to imply
for 1 <k ≤ s < ∞. Using this result we establish several inclusion theorems as well as conditions for the equivalence of
and
. 相似文献
7.
In this paper we extend the Darboux theory of integrability in ℝ
n
to the regular algebraic hypersurfaces. Then we apply the extended theory first to the 3-dimensional generalized cylinders
×ℝ3−r
of ℝ4 forr=0, 1, 2, 3; and after to then-dimensional sphere
of ℝ
n+1. 相似文献
8.
T. Levasseur 《Transformation Groups》1998,3(4):337-353
Let
u
be a compact Lie algebra and let
u
be its complexification. Let ζ−1/2 be the inverse on the set of regular elements of
u
of a square root of the discriminant of
. Generalizing a result of W. Lichtenstein in the case
u
=
(n, ℂ) or
(nℝ), we prove that ∂(q).ζ1/2 is non zero for all harmonic polynomialsq ∈S(
) \ {0}. This fact is deduced from results about equivariantD-modules supported on the nilpotent cone of
. 相似文献
9.
Moshe Dubiner 《Journal d'Analyse Mathématique》1995,67(1):39-116
We consider the problem of polynomial approximation to a real valued functionf defined on a compact set
. An approximation theorem is proven in terms of the newly defined modulus of approximation. It is shown to imply a multidimensional
Jackson type theorem which is stronger than previously known results even for the interval [−1, 1]. A strong multidimensional
Bernstein type inverse theorem is also proven. We allow quite general approximation quasi-norms including
for 0<q≤∞.
We have found that the space of polynomials ℙ on a compact setX induces a semimetric
which encapsulates the local structure of ℙ. Any semimetric ρ equivalent to
suffices for the rough theory presented here. Many examples of sets
and their metrics are presented. 相似文献
10.
We show that for a
-action Ψ being the Kronecker sum of a symbolic strictly ergodic
-actionT and a Chacon
-actionS, the rank (covering number) of Ψ is the same as that forT. Using this result we construct, for a given natural numberr≥2 and a real numberb∈(0,1) withr\b≥1, a
-action with rankr, covering numberb and a simple spectrum. On the other hand, for any positive integersr, m with 1≤m≤r≤∞ we construct a
-action with rankr and spectral multiplicitym. 相似文献
11.
In this paper, we use Laguerre calculus to find theLP spectrum (λ, Μ) of the pair (L, iT). Here
md T = ∂/∂t with
a basis for the left-invariant vector fields on the Heisenberg group. We find kernels for the spectral projection operators
on the ray λ > 0 in the Heisenberg brush and show that they are Calderón-Zygmund-Mikhlin operators. Estimates for these operators
in L
k
p
(Hn), HP(Hn), and S
k
pv
(Hn) spaces can therefore be deduced. 相似文献
12.
Keiji Izuchi 《Journal d'Analyse Mathématique》1998,75(1):135-154
Letb be a Blaschke product with zeros {z
n
} in the open unit disk Δ. Let
be the set of sequences of non-negative integersp=(p
1,p
2,…) such that ∑
n=1
∞
p
n
(1 − |z
n
|) < ∞ andp
n
→∞ asn→∞. We study the class of weak infinite powers ofb,
Properties of these classes depend on the setS(b) of the cluster points in ∂Δ of {z
n
}. It is proved thatS(b)=∂Δ if and only if
, the Douglas algebra generated by
. Also, it is proved thatdθ(S(b))=0 if and only if there exists an interpolating Blaschke productB such that
. 相似文献
13.
Mats Andersson 《Journal d'Analyse Mathématique》1996,68(1):39-58
LetG
1,…,Gm be bounded holomorphic functions in a strictly pseudoconvex domainD such that
. We prove that for each
(0,q)-form ϕ inL
p(∂D), 1<p<∞, there are
formsu
1, …,u
m inL
p(∂D) such that ΣG
juj=ϕ. This generalizes previous results forq=0. The proof consists in delicate estimates of integral representation formulas of solutions and relies on a certainT1 theorem due to Christ and Journé. For (0,n−1)-forms there is a simpler proof that also gives the result forp=∞. Restricted to one variable this is precisely the corona theorem.
The author was partially supported by the Swedish Natural Research Council. 相似文献
14.
We consider two-phase metrics of the form ϕ(x, ξ) ≔
, where α,β are fixed positive constants and B
α, B
β are disjoint Borel sets whose union is ℝN, and prove that they are dense in the class of symmetric Finsler metrics ϕ satisfying
. Then we study the closure
of the class
of two-phase periodic metrics with prescribed volume fraction θ of the phase α. We give upper and lower bounds for the class
and localize the problem, generalizing the bounds to the non-periodic setting. Finally, we apply our results to study the
closure, in terms of Γ-convergence, of two-phase gradient-constraints in composites of the type f(x, ∇ u) ≤ C(x), with C(x) ∈ {α, β } for almost every x. 相似文献
15.
Zoé Chatzidakis 《Israel Journal of Mathematics》1986,55(2):173-183
LetK be a hilbertian field,G(K) its absolute Galois group. IfK is countable, then for a.a.
inG(K)
e
,
and there is no intermediate field
with
. Let
∈G(K)
e
. Then for a.a.
in
. 相似文献
16.
L. Brandolini G. Gigante A. Greenleaf A. Iosevich A. Seeger G. Travaglini 《Journal of Geometric Analysis》2007,17(1):15-40
We consider Fourier transforms
of densities supported on curves in ℝd. We obtain sharp lower and close to sharp upper bounds for the decay rates of
as R → ∞. 相似文献
17.
Zbigniew Slodkowski 《Journal of Geometric Analysis》1997,7(4):637-651
We consider an arbitrary real analytic family Xz,
, over the closed unit disc
, of real analytic plane Jordan curves Xz. Ifj
e
iθ
,e
iθ
∋ ∂D, is an arbitrary real-analytic family of orientation-reversing homeomorphisms of
fixingX
e
iθ
pointwise, we show that there is a unique holomorphic motion of
extending the given motion of Jordan curves and consistent with the given family of involutions. If these generalized reflections
are defined using the barycentric extension construction of Douady-Earle-Nag, then the resulting extension method for holomorphic
motions of X is natural, that is Moebius-invariant and continuous with respect to variation of the given motion of X0. 相似文献
18.
V. V. Andrievskii 《Journal d'Analyse Mathématique》2005,96(1):283-295
LetG⊂C be a quasidisk,K ⊂ G be a compact set, andp
n be a non-constant complex polynomial of degree at mostn. We establish the inequality
whereα
n < 0 depends onn, K,
and the geometrical structure of ϖG. 相似文献
19.
B. Yousefi 《Rendiconti del Circolo Matematico di Palermo》2002,51(3):403-410
Let
be a sequence of positive numbers and 1≤p<∞. We consider the spaceH
p(β) of all power series
such that Σ|
(n)|p β(n
p<∞. We investigate regions on which our formal power series represent bounded analytic functions.
Research partially supported by the Shiraz University Research Council Grant No. 79-SC-1311-675. 相似文献
20.
In this article we give a necessary and sufficient condition for a pair of wavelet families
in L2(ℝ
n
), to arise from a pair of biorthogonal MRA’s. The condition is given in terms of simple equations involving the functions
ψℓ and
. To work in greater generality, we allow multiresolution analyses of arbitrary multiplicity, based on lattice translations
and matrix dilations. Our result extends the characterization theorem of G. Gripenberg and X. Wang for dyadic orthonormal
wavelets in L2(ℝ),and includes, as particular cases, the sufficient conditions of P. Auscher and P.G. Lemarié in the biorthogonal situation. 相似文献