共查询到20条相似文献,搜索用时 31 毫秒
1.
Chen Jiecheng Zhu Xiangrong 《高校应用数学学报(英文版)》2005,20(3):316-322
Given a positive Radon measure μ on R^d satisfying the linear growth condition μ(B(x,r))≤C0r^n,x∈R^d,r〉0,(1) where n is a fixed number and O〈n≤d. When d-1〈n,it is proved that if Tt,N1=0,then the corresponding maximal Calderon-Zygmund singular integral is bounded from RBMO to itself only except that it is infinite μ-a. e. on R^d. 相似文献
2.
M.M. Cavalcanti V.N. Domingos Cavalcanti 《NoDEA : Nonlinear Differential Equations and Applications》2000,7(3):285-307
This paper is concerned to the existence, uniqueness and uniform decay for the solutions of the coupled Klein-Gordon-Schr?dinger
damped equations
where ω is a bounded domain of R
n
, n≤ 3, F : R
2→R is a C
1-function; γ, β; θ are constants such that γ, β > 0 and 1 ≤ 2θ≤ 2.
Received January 1999 – Accepted October 1999 相似文献
3.
Walter Senn 《manuscripta mathematica》1991,71(1):45-65
We consider a variational problem with an integrandF:R
n
×R×R
n
→R that isZ-periodic in the firstn+1 variables and satisfies certain growth-conditions. By a recent result of Moser, there exist for every α∈R
n
minimal solutionsu:R
n
→R minimising ƒF(x, u(x), u
x
(x)) dx with respect to compactly supported variations ofu and such that sup |u(x)-αx|<∞. Given such a minimal solutionu we define the average action
(whereB
r
is ther-ball around 0∈R
n
) and show thatM(α) is indeed independent of the minimal solutionu satisfying sup |u(x)-αx|<∞. We prove that this average actionM(α) is strictly convex in α.
相似文献
4.
Raising Roofs,Crashing Cycles,and Playing Pool: Applications of a Data Structure for Finding Pairwise Interactions 总被引:3,自引:0,他引:3
The straight skeleton of a polygon is a variant of the medial axis introduced by Aichholzer et al., defined by a shrinking
process in which each edge of the polygon moves inward at a fixed rate. We construct the straight skeleton of an n -gon with r reflex vertices in time O(n
1+ε
+ n
8/11+ε
r
9/11+ε
) , for any fixed ε >0 , improving the previous best upper bound of O(nr log n) . Our algorithm simulates the sequence of collisions between edges and vertices during the shrinking process, using a technique
of Eppstein for maintaining extrema of binary functions to reduce the problem of finding successive interactions to two dynamic
range query problems: (1) maintain a changing set of triangles in R
3 and answer queries asking which triangle is first hit by a query ray, and (2) maintain a changing set of rays in R
3 and answer queries asking for the lowest intersection of any ray with a query triangle. We also exploit a novel characterization
of the straight skeleton as a lower envelope of triangles in R
3 . The same time bounds apply to constructing non-self-intersecting offset curves with mitered or beveled corners, and similar
methods extend to other problems of simulating collisions and other pairwise interactions among sets of moving objects.
Received July 1, 1998, and in revised form March 29, 1999. 相似文献
5.
For natural numbers r,s,q,m,n with s≥r≤q we determine all natural functions g: T
*(J
(r,s,q)(Y, R
1,1)0)*→R for any fibered manifold Y with m-dimensional base and n-dimensional fibers. For natural numbers r,s,m,n with s≥r we determine all natural functions g: T
*(J
(r,s)
(Y, R)0)*→R for any Y as above. 相似文献
6.
T. Bloom 《Constructive Approximation》2001,17(1):91-102
Let {r
n
} be a sequence of rational functions deg( r
n
≤ n) that converge rapidly in measure to an analytic function f on an open set in C
N
. We show that {r
n
} converges rapidly in capacity to f on its natural domain of definition W
f
(which, by a result of Goncar, is an open subset of C
N
).
In particular, for f meromorphic on C
N
and analytic near zero the sequence of Padé approximants {π
n
(z, f, λ)} (as defined by Goncar) converges rapidly in capacity to f on C
N
.
January 14, 1999. Date revised: October 7, 1999. Date accepted: November 1, 1999. 相似文献
7.
László Lovász 《Mathematical Programming》1999,86(3):443-461
It is shown that the “hit-and-run” algorithm for sampling from a convex body K (introduced by R.L. Smith) mixes in time O
*(n
2
R
2/r
2), where R and r are the radii of the inscribed and circumscribed balls of K. Thus after appropriate preprocessing, hit-and-run produces an approximately uniformly distributed sample point in time O
*(n
3), which matches the best known bound for other sampling algorithms. We show that the bound is best possible in terms of R,r and n.
Received January 26, 1998 / Revised version received October 26, 1998?Published online July 19, 1999 相似文献
8.
Frank Loose 《代数通讯》2013,41(7):2395-2416
Abstract A ring R is called left P-injective if for every a ∈ R, aR = r(l(a)) where l( ? ) and r( ? ) denote left and right annihilators respectively. The ring R is called left GP-injective if for any 0 ≠ a ∈ R, there exists n > 0 such that a n ≠ 0 and a n R = r(l(a n )). As a response to an open question on GP -injective rings, an example of a left GP-injective ring which is not left P-injective is given. It is also proved here that a ring R is left FP -injective if and only if every matrix ring 𝕄 n (R) is left GP-injective. 相似文献
9.
Jouko Tervo 《Israel Journal of Mathematics》1988,63(1):41-66
The paper considers a boundary value problem with the help of the smallest closed extensionL
∼ :H
k →H
k
0×B
h
1×...×B
h
N
of a linear operatorL :C
(0)
∞
(R
+
n
) →L(R
+
n
)×L(R
n−1)×...×L(R
n−1). Here the spacesH
k (the spaces ℬ
h
) are appropriate subspaces ofD′(R
+
n
) (ofD′(R
n−1), resp.),L(R
+
n
) andC
(0)
∞
(R
+
n
)) denotes the linear space of smooth functionsR
n
→C, which are restrictions onR
+
n
of a function from the Schwartz classL (fromC
0
∞
, resp.),L(R
n−1) is the Schwartz class of functionsR
n−1 →C andL is constructed by pseudo-differential operators. Criteria for the closedness of the rangeR(L
∼) and for the uniqueness of solutionsL
∼
U=F are expressed. In addition, ana priori estimate for the corresponding boundary value problem is established. 相似文献
10.
H. Maehara 《Discrete and Computational Geometry》1995,13(1):585-592
We present a special similarity ofR
4n
which maps lattice points into lattice points. Applying this similarity, we prove that if a (4n−1)-polytope is similar to a lattice polytope (a polytope whose vertices are all lattice points) inR
4n
, then it is similar to a lattice polytope inR
4n−1, generalizing a result of Schoenberg [4]. We also prove that ann-polytope is similar to a lattice polytope in someR
N
if and only if it is similar to a lattice polytope inR
2n+1, and if and only if sin2(<ABC) is rational for any three verticesA, B, C of the polytope. 相似文献
11.
In this paper, we prove the validity of the Chern conjecture in affine geometry [18], namely that an affine maximal graph
of a smooth, locally uniformly convex function on two dimensional Euclidean space, R
2, must be a paraboloid. More generally, we shall consider the n-dimensional case, R
n
, showing that the corresponding result holds in higher dimensions provided that a uniform, “strict convexity” condition holds.
We also extend the notion of “affine maximal” to non-smooth convex graphs and produce a counterexample showing that the Bernstein
result does not hold in this generality for dimension n≥10.
Oblatum 16-IV-1999 & 4-XI-1999?Published online: 21 February 2000 相似文献
12.
Robert Kaufman Jeremy T. Tyson Jang-Mei Wu 《Publications Mathématiques de L'IHéS》2005,101(1):209-241
According to a theorem of Martio, Rickman and Väisälä, all nonconstant Cn/(n-2)-smooth quasiregular maps in Rn, n≥3, are local homeomorphisms. Bonk and Heinonen proved that the order of smoothness is sharp in R3. We prove that the order of smoothness is sharp in R4. For each n≥5 we construct a C1+ε(n)-smooth quasiregular map in Rn with nonempty branch set. 相似文献
13.
To a given immersion
i:Mn? \mathbb Sn+1{i:M^n\to \mathbb S^{n+1}} with constant scalar curvature R, we associate the supremum of the squared norm of the second fundamental form sup |A|2. We prove the existence of a constant C
n
(R) depending on R and n so that R ≥ 1 and sup |A|2 = C
n
(R) imply that the hypersurface is a H(r)-torus
\mathbb S1(?{1-r2})×\mathbb Sn-1 (r){\mathbb S^1(\sqrt{1-r^2})\times\mathbb S^{n-1} (r)}. For R > (n − 2)/n we use rotation hypersurfaces to show that for each value C > C
n
(R) there is a complete hypersurface in
\mathbb Sn+1{\mathbb S^{n+1}} with constant scalar curvature R and sup |A|2 = C, answering questions raised by Q. M. Cheng. 相似文献
14.
Recently, A. Cohen, R. A. DeVore, P. Petrushev, and H. Xu investigated nonlinear approximation in the space BV (R
2
). They modified the classical adaptive algorithm to solve related extremal problems. In this paper, we further study the
modified adaptive approximation and obtain results on some extremal problems related to the spaces V
σ,p
r
(R
d
) of functions of ``Bounded Variation" and Besov spaces B
α
(R
d
).
November 23, 1998. Date revised: June 25, 1999. Date accepted: September 13, 1999. 相似文献
15.
The p
n
-sequence of a semigroup S is said to be polynomially bounded, if there exist a positive constant c and a positive integer r such that the inequality p
n
(S) ≤cn
r
holds for all n≥ 1. In this paper, we fully describe all finite semigroups having polynomially bounded p
n
-sequences. First we give a characterization in terms of identities satisfied by these semigroups. In the sequel, this result
will allow an insight into the structure of such semigroups. We are going to deal with certain ideals and the construction
of ideal extension of semigroups. In addition, we supply an effective procedure for deciding whether a finite semigroup has
polynomially bounded p
n
-sequence and give some examples.
Received March 5, 1999; accepted in final form November 1, 1999. 相似文献
16.
Jacek Tabor 《Aequationes Mathematicae》1995,49(1):300-303
Summary In this paper we prove that, ifS ×R
n
is homeomorphic toR
n + 1, thenS is homeomorphic toR. 相似文献
17.
Jacob Feldman 《Israel Journal of Mathematics》1980,36(3-4):321-345
A new approach is given to the entropy of a probability-preserving group action (in the context ofZ and ofR
n
), by defining an approximate “r-entropy”, 0<r<1, and lettingr → 0. If the usual entropy may be described as the growth rate of the number of essential names, then ther-entropy is the growth rate of the number of essential “groups of names” of width≦r, in an appropriate sense. The approach is especially useful for actions of continuous groups. We apply these techniques to
state and prove a “second order” equipartition theorem forZ
m
×R
n
and to give a “natural” proof of Ornstein’s isomorphism theorem for Bernoulli actions ofZ
m
×R
n
, as well as a characterization of such actions which seems to be the appropriate generalization of “finitely determined”. 相似文献
18.
Ifn>2 and iff is a locally quasiconformal mapping from the ballB
n= {x∈R
n:⋎x⋎<1} intoR
n ∪ {∞} thenf is injective inB
n (r)={x∈R
n:⋎x⋎ <r} wherer>0 depends only onn and the maximal dilatation off.
Supported in part by the Samuel Neaman Fund, Special Year in Complex Analysis, Technion, I.I.T., Haifa, Israel, 1975/76. 相似文献
19.
Nikolaos Efstathiou Sofronidis 《Archive for Mathematical Logic》2005,44(7):801-815
The purpose of this paper is first to show that if X is any locally compact but not compact perfect Polish space and stands for the one-point compactification of X, while EX is the equivalence relation which is defined on the Polish group C(X,R+*) by where f, g are in C(X,R+*), then EX is induced by a turbulent Polish group action. Second we show that given any if we identify the n-dimensional unit sphere Sn with the one-point compactification of Rn via the stereographic projection, while En,r is the equivalence relation which is defined on the Polish group Cr(Rn,R+*) by where f, g are in Cr(Rn,R+*), then En,r is also induced by a turbulent Polish group action.
Dedicated to my sister Alexandra and to her daughter Marianthi. 相似文献
20.
Peter Lindqvist 《Israel Journal of Mathematics》1984,47(4):291-295
Letf:R
n→Rn be locally quasiregular in the sense that the restriction off to any ball |x|<r has finite inner dilatationK
1(r). Suppose that the growth condition ∫∞r-1K1(r)1/(1-n) holds. Then Liouville’s theorem is valid:If f is bounded, f is a constant. An example shows that this growth condition is relatively sharp. 相似文献