共查询到20条相似文献,搜索用时 31 毫秒
1.
In this paper, we consider the almost everywhere convergenc of Bochner—Riesz means below the critical index in Bessel potential
spacesL
a
p
(1≤p≤2 anda>0) and find out the relation between the index of Bochner—Riesz means and the degree of smoothness of functions. 相似文献
2.
H. Brézis 《Israel Journal of Mathematics》1971,9(4):513-534
Let φ be a convex l.s.c. function fromH (Hilbert) into ] - ∞, ∞ ] andD(φ)={u ∈H; φ(u)<+∞}. It is proved that for everyu
0 ∈D(φ) the equation − (du/dt)(t ∈ ∂φ(u(t)),u(0)=u
0 has a solution satisfying ÷(du(t)/dt)÷ ≦(c
1/t)+c
2. The behavior ofu(t) in the neighborhood oft=0 andt=+∞ as well as the inhomogeneous equation (du(t)/dt)+∂φ(u(t)) ∈f(t) are then studied. Solutions of some nonlinear boundary value problems are given as applications.
相似文献
3.
LetD be a pseudoconvex domain with real analytic boundary in C2. A subsetE of ∂D is a local peak set for
if for everyp ∈ ∂D, there exist a neighborhoodU ofp and a holomorphic functionf onU such thatf = 1 onE∩U and |f| < 1 on
. We give conditions for the existence of real analytic LPι curves in ∂D through a point of finite type.
On the other hand, we give examples showing that: (a) there exist a domainD and a real analytic curve γ in ∂D such that the complexification of γ intersectsD only along γ, but γ is not LPι, and (b) there exist a domain D and a pointp ∈ ∂D, which is LPι, of finite type, but such that ∂D contains no real analytic LP∂ curve throughp. 相似文献
4.
In accordance with the demands of the so-called local approach to inverse problems, the set of “waves” uf (·, T) is studied, where uf (x,t) is the solution of the initial boundary-value problem utt−Δu=0 in Ω×(0,T), u|t<0=0, u|∂Ω×(0,T)=f, and the (singular) control f runs over the class L2((0,T); H−m (∂Ω)) (m>0). The following result is established. Let ΩT={x ∈ Ω : dist(x, ∂Ω)<T)} be a subdomain of Ω ⊂ ℝn (diam Ω<∞) filled with waves by a final instant of time t=T, let T*=inf{T : ΩT=Ω} be the time of filling the whole domain Ω. We introduce the notation Dm=Dom((−Δ)m/2), where (−Δ) is the Laplace operator, Dom(−Δ)=H2(Ω)∩H
0
1
(Ω);D−m=(Dm)′;D−m(ΩT)={y∈D−m:supp y ⋐ ΩT. If T<T., then the reachable set R
m
T
={ut(·, T): f ∈ L2((0,T), H−m (∂Ω))} (∀m>0), which is dense in D−m(ΩT), does not contain the class C
0
∞
(ΩT). Examples of a ∈ C
0
∞
, a ∈ R
m
T
, are presented.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 210, 1994, pp. 7–21.
Translated by T. N. Surkova. 相似文献
5.
Paul F. X. Müller 《Israel Journal of Mathematics》1988,63(2):212-222
LetX
D
p
be the span of the Haar function {h
j: J ε D} inL
p (1 <p < ∞) endowed withL
p norm. Then for any finite setD, the spacesX
D
p
andl
*D
p
areK
p-isomorphic whereK
p depends onp only. 相似文献
6.
Whenϕ is an analytic map of the unit diskU into itself, andX is a Banach space of analytic functions onU, define the composition operatorC
ϕ
byC
ϕ
(f)=f o ϕ, forf∈X. In this paper we show how to use the Calderón theory of complex interpolation to obtain information on the spectrum ofC
ϕ
(under suitable hypotheses onϕ) acting on the Bloch spaceB and BMOA, the space of analytic functions in BMO. To do this we first obtain some results on the essential spectral radius
and spectrum ofC
ϕ
on the Bergman spacesA
pand Hardy spacesH
p,spaces which are connected toB and BMOA by the interpolation relationships [A
1,B]
t
=A
pand [H
1,BMOA]
t
=H
pfor 1=p(1−t). 相似文献
7.
Explosive solutions of elliptic equations with absorption and nonlinear gradient term 总被引:2,自引:0,他引:2
Marius Ghergu Constantin Niculescu Vicenţiu Rădulescu 《Proceedings Mathematical Sciences》2002,112(3):441-451
Letf be a non-decreasing C1-function such that
andF(t)/f
2
a(t)→ 0 ast → ∞, whereF(t)=∫
0
t
f(s) ds anda ∈ (0, 2]. We prove the existence of positive large solutions to the equationΔu +q(x)|Δu|
a
=p(x)f(u) in a smooth bounded domain Ω ⊂RN, provided thatp, q are non-negative continuous functions so that any zero ofp is surrounded by a surface strictly included in Ω on whichp is positive. Under additional hypotheses onp we deduce the existence of solutions if Ω is unbounded. 相似文献
9.
A. Bonilla F. Pérez-González A. Stray R. Trujillo-González 《Journal d'Analyse Mathématique》1997,73(1):65-89
This paper is concerned with several approximation problems in the weighted Hardy spacesH
p(Ω) of analytic functions in the open unit disc D of the complex plane ℂ. We prove that ifX is a relatively closed subset of D, the class of uniform limits onX of functions inH
p(Ω) coincides, moduloH
p(Ω), with the space of uniformly continuous functions on a certain hull ofX which are holomorphic on its interior. We also solve the simultaneous approximation problems of describing Farrell and Mergelyan
sets forH
p(Ω), giving geometric characterizations for them. By replacing approximating polynomials by polynomial multipliers of outer
functions, our results lead to characterizations of the same sets with respect to cyclic vectors in the classical Hardy spacesH
p(D), 1 ⪯p < ∞.
Dedicated to Professor Nácere Hayek on the occasion of his 75th birthday. 相似文献
10.
Let 0<p≤1<q<0, andw
1
,w
2
∈ A
1
(Muckenhoupt-class). In this paper the authors prove that the strongly singular convolution operators are bounded from the
homogeneous weighted Herz-type Hardy spacesH Kα, p
q(w1; w2) to the homogeneous weighted Herz spacesK
α, p
q
(w1; w2), provided α=n(1−1/q). Moreover, the boundedness of these operators on the non-homogeneous weighted Herz-type Hardy spacesH K
α, p
q
(w
1;w
2) is also investigated.
Supported by the National Natural Science Foundation of China 相似文献
11.
Liliana Gabriela Gheorghe 《Annali di Matematica Pura ed Applicata》2001,180(2):203-210
We study membership to Schatten ideals S
E
, associated with a monotone Riesz–Fischer space E, for the Hankel operators H
f
defined on the Hardy space H
2(∂D). The conditions are expressed in terms of regularity of its symbol: we prove that H
f
∈S
E
if and only if f∈B
E
, the Besov space associated with a monotone Riesz–Fischer space E(dλ) over the measure space (D,dλ) and the main tool is the interpolation of operators.
Received: December 17, 1999; in final form: September 25, 2000?Published online: July 13, 2001 相似文献
12.
The main results of the paper are: (1) The boundedness of singular integral operators in the variable exponent Lebesgue spaces
L
p(·)(Γ, w) on a class of composed Carleson curves Γ where the weights w have a finite set of oscillating singularities. The proof of this result is based on the boundedness of Mellin pseudodifferential
operators on the spaces
Lp(·)(\mathbbR +,dm){L^{p(\cdot )}(\mathbb{R} _{+},d\mu)} where dμ is an invariant measure on multiplicative group ${\mathbb{R}_{+}=\left\{r\in \mathbb{R}:r >0 \right\}}${\mathbb{R}_{+}=\left\{r\in \mathbb{R}:r >0 \right\}}. (2) Criterion of local invertibility of singular integral operators with piecewise slowly oscillating coefficients acting
on L
p(·)(Γ, w) spaces. We obtain this criterion from the corresponding criteria of local invertibility at the point 0 of Mellin pseudodifferential
operators on
\mathbbR+{\mathbb{R}_{+}} and local invertibility of singular integral operators on
\mathbbR{\mathbb{R}}. (3) Criterion of Fredholmness of singular integral operators in the variable exponent Lebesgue spaces L
p(·)(Γ, w) where Γ belongs to a class of composed Carleson curves slowly oscillating at the nodes, and the weight w has a finite set of slowly oscillating singularities. 相似文献
13.
Xiao Jie 《数学学报(英文版)》1994,10(2):192-201
LetD={z∈Σ:|z|<1} and ϕ be a normal function on [0,1). Forp∈(0,1) such a function ϕ is used to define a Bergman spaceA
p
(ϕ) onD with weight ϕ
p
(|·|)/(1-|·|2). In this paper, the dual space ofA
p
(ϕ) is given, four characteristics of Carleson measure onA
p
(ϕ) are obtained. Moreover, as an application, three sequence interpolation theorems inA
p
(ϕ) are derived.
Supported by the Doctoral Program Foundation of Institute of Higher Education, P.R. China. 相似文献
14.
Summary. This is a continuation of our previous work [6] on the investigation of intermittency for the parabolic equation (∂/∂t)u=Hu on ℝ+×ℤ
d
associated with the Anderson Hamiltonian H=κΔ+ξ(·) for i.i.d. random potentials ξ(·). For the Cauchy problem with nonnegative
homogeneous initial condition we study the second order asymptotics of the statistical moments <u(t,0)
p
> and the almost sure growth of u(t,0) as t→∞. We point out the crucial role of double exponential tails of ξ(0) for the formation of high intermittent peaks of the
solution u(t,·) with asymptotically finite size. The challenging motivation is to achieve a better understanding of the geometric structure
of such high exceedances which in one or another sense provide the essential contribution to the solution.
Received: 10 December 1996 / In revised form: 30 September 1997 相似文献
15.
Jean-René Licois 《Journal d'Analyse Mathématique》1995,66(1):1-36
LetM be a compact riemannian manifold,h an odd function such thath(r)/r is non-decreasing with limit 0 at 0. Letf(r)=h(r)-γr and assume there exist non-negative constantsA andB and a realp>1 such thatf(r)>Ar
P-B. We prove that any non-negative solutionu ofu
tt+Δgu=f(u) onM x ℝ+ satisfying Dirichlet or Neumann boundary conditions on ϖM converges to a (stationary) solution of Δ
g
Φ=f(Φ) onM with exponential decay of ‖u-Φ‖C
2(M). For solutions with non-constant sign, we prove an homogenisation result for sufficiently small λ; further, we show that
for every λ the map (u(0,·),u
t(0,·))→(u(t,·), u
t(t,·)) defines a dynamical system onW
1/2(M)⊂C(M)×L
2(M) which possesses a compact maximal attractor.
相似文献
16.
Leoni Dalla 《Israel Journal of Mathematics》1989,68(3):353-364
In this paper, generalizing the notion of a path we define ak-area to be the setD={g(t):t ∈J} on thek-skeleton of a convex compact setK in a Hilbert space, whereg is a continuous injection map from thek-dimensional convex compact setJ to thek-skeleton ofK. We also define anE
k-area onK, whereE
k is ak-dimensional subspace, to be ak-area with the propertyπ(g(t))=t,t ∈π(K), whereπ is the orthogonal projection onE
k. This definition generalizes the notion of an increasing path on the 1-skeleton ofK. The existence of such sets is studied whenK is a subset of a Euclidean space or of a Hilbert space. Finally some conjectures are quoted for the number of such sets in
some special cases. 相似文献
17.
Donald St. P. Richards 《Annals of the Institute of Statistical Mathematics》1982,34(1):119-121
Summary LetC
κ(S) be the zonal polynomial of the symmetricm×m matrixS=(sij), corresponding to the partition κ of the non-negative integerk. If ∂/∂S is them×m matrix of differential operators with (i, j)th entry ((1+δij)∂/∂sij)/2, δ being Kronecker's delta, we show that Ck(∂/∂S)Cλ(S)=k!δλkCk(I), where λ is a partition ofk. This is used to obtain new orthogonality relations for the zonal polynomials, and to derive expressions for the coefficients
in the zonal polynomial expansion of homogenous symmetric polynomials. 相似文献
18.
Suppose π1(E, F) is the space of all absolutely 1-summing operators between two Banach spacesE andF. We show that ifF has a copy of c0, then π1 (E, F) will have a copy of c0, and under some conditions ifE has a copy of ℓ1 then π1 (E, F) would have a complemented copy of ℓ1. 相似文献
19.
J. Hounie Rafael Augusto dos Santos Kapp 《Journal of Fourier Analysis and Applications》2009,15(2):153-178
In this work, we study the continuity of pseudodifferential operators on local Hardy spaces h
p
(ℝ
n
) and generalize the results due to Goldberg and Taylor by showing that operators with symbols in S
1,δ
0(ℝ
n
), 0≤δ<1, and in some subclasses of S
1,10(ℝ
n
) are bounded on h
p
(ℝ
n
) (0<p≤1). As an application, we study the local solvability of the planar vector field L=∂
t
+ib(x,t)∂
x
, b(x,t)≥0, in spaces of mixed norm involving Hardy spaces.
Work supported in part by CNPq, FINEP, and FAPESP. 相似文献
20.
Vladimir Shpilrain 《Israel Journal of Mathematics》1995,91(1-3):307-316
LetE be a bounded Borel subset of ℝn,n≥2, of positive Lebesgue measure andP
E the corresponding ‘Pompeiu transform”. We prove thatP
E is injective onL
p(ℝn) if 1≤p≤2n/(n-1). We explore the connection between this problem and a Wiener-Tauberian type theorem for theM(n) action onL
q(ℝn) for various values ofq. We also take up the question of whenP
E is injective in caseE is of finite, positive measure, but is not necessarily a bounded set. Finally, we briefly look at these questions in the
contexts of symmetric spaces of compact and non-compact type. 相似文献