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1.
XuSenlin DengQintao ChenDongmei 《分析论及其应用》2004,20(3):288-293
Let M be a compact minimal hypersurface of sphere Sn 1(1). Let (M) be H (r)-torus of sphere Sn 1 (1).Assume they have the same constant mean curvature H, the result in [1] is that ifSpec0(M, g) =Spec0((M), g),then for 3≤ n ≤ 6, r2≤n-1/n or n ≥ 6, r2 ≥ n-1, then M is isometric to (M). We improved the result and prove that: if Spec0(M,g) =Spec0((M),g), then M is isometric to (M). Generally, if Specp(M,g) =Specp((M),g), here p is fixed and satisfies that n(n - 1) ≠ 6p(n - p), then M is isometric to (M). 相似文献
2.
WangJianli ZhouSongping 《分析论及其应用》2003,19(3):280-288
The present paper deals with best onesided approximation rate in Lp spaces ^~En(f)Lp of f∈C2π.Although it is clear that the estimate ^~E(f)Lp≤C‖f‖Lp cannot be correct for all f∈L^p2π in case p<∞, the question whether ~En(f)Lp≤Cω(f,n^-l)Lp or ^~En(f)Lp≤CEn(f)Lp holds for f∈ C2π remains totally untouched.Therefore it forms a basic problem to justify onesided approximation. The present paper will provide an answer to settle down the basis. 相似文献
3.
For arbitrary given positive term series
and
, the present paper provides an interesting necessary and sufficient condition for
.
In Memory of Professor M. T. Cheng
The Research Project of the Mathematical Institute, Ningbo University.
Supported in part by Zhejiang Provincial Natural Science Foundation, and by State Key Laboratory of Southwest Institute of
Petroleum. 相似文献
4.
In this paper we consider the class
consisting of analytic functions with negative coefficients and fixed second coefficient. The object of the present paper
is to give coefficient estimates, convex linear combinations, some distortion theorems and radii of starlikeness and convexity
for f(z) in the class
.
The work is supported by UKM grant ST-028-2003 and IRPA grant 09-02-02-80 EA208, Malysia.
This paper is that of a talk on the “International Conference at Analysis in Theory and Applications” held in Nanjing, P.
R. China, July, 2004. 相似文献
5.
Summary LetG be the coadjoint group of a finite-dimensional complex Lie algebrag. Forg solvable, the Dixmier-map is known to be a homeomorphism
of the orbit space
/G onto the space χ of primitive ideals in the enveloping algebra U(G) [6,15]. For
, the Dixmier-map is known to be a bijection (and in general not a homeomorphism)
with the space χl of all completely prime primitive ideals [7, 16]. Here we derive from a result ofW. SOERGEL [18], that this map issheet- wise a homeomorphism onto the image. Here a sheet is a maximal irreducible subset consisting of orbits of a fixed dimension; obviouslyg decomposes into finitely many sheets [3]. The results of this paper hold more generally forg semisimple, if one restricts to a sheet of polarizable orbits, where a Dixmier-map can be defined.
Relative to a fixed polarization (a parabolic subalgebra)p ⊂g let I be the annihilator of the generic module induced from p. The „relative enveloping algebra“
) has been studied e.g. bySOERGEL [19, 18]. Its center Z is described here by a relative Harish-Chandra isomorphism of the normalization
with a suitable ring of group invariants (3.2). We study here the extension
ofU by
. We suggest that this very mild central extension ofU generates good properties and is very suitable for the study of the Dixmier-map (cf.4.3,5.6).
In particular, we conjecture in case
: Every minimal primitive ideal of
is generated by a maximal ideal of the center. This would generalize for
a well known theorem ofM. Duflo (casep Borel, where
).
AsJ. Dixmier communicated in a letter, the main result here is exactly what he had hoped for when he first introduced a notion of sheets
many years ago.
Added in proof: This conjecture will be proved in a subsequent paper. 相似文献
Added in proof: This conjecture will be proved in a subsequent paper. 相似文献
6.
Chen Debao 《分析论及其应用》1993,9(3):17-28
In this paper we study the degree of approximation by superpositions of a sigmoidal function. We mainly consider the univariate
case. If f is a continuous function, we prove that for any bounded sigmoidal function σ,
. For the Heaviside function H(x), we prove that
. If f is a continuous function of bounded variation, we prove that
and
. For he Heaviside function, the coefficient 1 and the approximation orders are the best possible. We compare these results
with the classical Jackson and Bernstein theorems, and make some conjectures for further study. 相似文献
7.
K. A. Kopotun 《分析论及其应用》1995,11(2):41-58
Some estimates for unconstrained and convex polynomial approximation in the uniform metric are obtained. These results are
given in terms of the Ditzian-Totik moduli of smoothness
, ≤1 with
. The construction of the approximating polynomials does not depend on λ. 相似文献
8.
Oswald Riemenschneider 《manuscripta mathematica》1974,14(1):91-99
Let
be a 1-convex holomorphic mapping between complex spaces
resp.S, and let
be the blowingdown factorization of
over S. We prove in part 1 of the present note: The fiber –1(s0) over a point s0S is the Remmert quotient of
if and only if every holomorphic function on
(defined in a neighborhood of the exceptional subvariety of that fiber) can be extended holomorphically to
. This is true, for instance, in the case:
flat, S reduced at s0 and dim
, =const for all sS. In part 2, we use this result to obtain the following: For any Riemann surface R with genus g2 there exists a 2-dimensional normal complex analytic singularity X such that the minimal resolution
of X contains R as exceptional subvariety, and
has a deformation over the unit disc S={|s|<1} which can not be blown down to a deformation of X. 相似文献
9.
Chen Dirong 《分析论及其应用》1994,10(4):110-117
Let G be a Polya frequency density and
its periodization. We get the exact value of upper approximation of S1
(G), which is a convolution class with kernel G, by cardinal splines corresponding to G. Similar result has been obtained for
periodic convolution class with kernel
as well.
Supported in part by Postdoctral Fellowship Foundation provided by Chinese Academy of Sciences 相似文献
10.
Cardinal Tchebycheffian B-splines, defined by weight functions of the form
with
, are investigated. It is shown that these B-splines are translation invariant, have a geometric representation and satisfy
a generalized Hermite-Genocchi formula. For pure exponential weight functions the above results lead to a product type expression
for the Fourier transform of the cardinal exponential B-splines, showing that these functions are convolutions of lower order
ones. Similar conclusions are obtained for the corresponding Greens' functions. 相似文献
11.
Michael Kallay 《Israel Journal of Mathematics》1974,17(2):149-161
Let
denote the class of plane convex bodies having a width functionw, wherew′ is absolutely continuous. It is proved that a body in
is determined (up to translation) by the radius of curvature function of its boundary. This result is then used for a characterization
of the extreme (indecomposable) bodies in
and for a density theorem for Reuleaux polygons in
.
The content of this paper is a revised version of a part of the Master of Science thesis written by the author under the supervision
of Professor Micha A. Perles at the Hebrew University of Jerusalem and submitted in October, 1971. 相似文献
12.
D. N. Dudin 《Mathematical Notes》1968,3(1):42-44
For an algebra
of subsets of a set X there is constructed a set
and an algebra of its subsets so that the mapping
is a one-to-one correspondence between
and
and for each additive measure on
the measure
on
defined by the equation
is countably additive.Translated from Matematicheskie Zametki, Vol. 3, No. 1, pp. 71–76, January, 1968.The author wishes to express his deep appreciation to S. V. Fomin, under whose guidance this paper was written. 相似文献
13.
Michael Christ 《Journal of Geometric Analysis》1991,1(3):193-230
For a large class of subharmonicφ, the equation
is studied in
. Pointwise upper bounds are derived for the distribution kernels of the canonical solution operator and of the orthogonal
projection onto the space of entire functions inH. Existence theorems inL
p norms are derived as a corollary. A class of counterexamples, related to the failure of
to be analytic-hypoelliptic on certain CR manifolds, is discussed.
Communicated by Steven Krantz 相似文献
14.
Dr. John Walsh 《Probability Theory and Related Fields》1970,14(3):169-188
Summary In this paper we treat a time-symmetrical Martin boundary theory for continuous parameter Markov chains. This is done by reversing the time sense of a Markov chainX
t
in such a way as to obtain a dual Markov chain
, and considering the two chains together. Various relations between the Martin exit boundaries
and
of these processes are studied. The exit boundary
of
, is in a sense an entrance boundary forX
t
and vice versa. After a natural identification of certain points in
and
one can topologizeI
in such a way thatboth X
t and
have standard modifications in this space which are right continuous, have left limits, and are strongly Markov.Research supported in part at Stanford University, Stanford, California under AFOSR 0049. 相似文献
15.
LetM, M′ be smooth, real analytic hypersurfaces of finite type in ℂn and
a holomorphic correspondence (not necessarily proper) that is defined on one side ofM, extends continuously up toM and mapsM to M′. It is shown that
must extend acrossM as a locally proper holomorphic correspondence. This is a version for correspondences of the Diederich-Pinchuk extension
result for CR maps. 相似文献
16.
We prove that for almost allσ ∈G ℚ the field
has the following property: For each absolutely irreducible affine varietyV of dimensionr and each dominating separable rational mapϕ:V→
there exists a point a ∈
such thatϕ(a) ∈ ℤr. We then say that
is PAC over ℤ. This is a stronger property then being PAC. Indeed we show that beside the fields
other fields which are algebraic over ℤ and are known in the literature to be PAC are not PAC over ℤ. 相似文献
17.
Let {zk=xk+iyk} be a sequence on upper half plane
and {si} be the number of appearence of zk in {z1,z2,...,zk}. Suppose sup si<+∞. Let ω(x) be a weight belonging to A∞ and
. We Consider the weighted Hardy space
and operator Tp mapping f(z)∈H
+w
p
into a sequence defined by
, 0<p≤+∞, j=1,2,.... Then Tp(H
+w
p
)=lp if and only if {zk} is uniformly separated. Besides the effective solution for interpolation is obtained.
Supported by National Science Foundation of China and Shanghai Youth Science Foundation 相似文献
18.
Wolfgang Henke 《manuscripta mathematica》1976,19(2):165-188
Let M, resp.
, denote Riemannian manifolds of dimensions m>4, resp.
=m+2, and of constant sectional curvatures C, resp.
, with
0 and
is a standard space form, then the foliation L is a (globally) trivial fibre bundle with fibre Sm–1. 相似文献
19.
1.IntroductionLetfibeaplanedomainwithsmoothboundaryonandWm,p(fl)betheusualSobolevspaceonnwithnormWhenp=2,pisusuallyomitted.WeshalldenotetheusualinnerproductinL'(fl)orLa(O)'by','),andinL'(ofl)by't').Weshallusethesamenotationstoindicatethedualltiesbetw... 相似文献
20.
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