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1.
Let R be a prime ring and its left Martindale quotient ring. Assume that a q-skew -derivation of R satisfies the identity relationfor all x R, where the subring of constants of on R. It is proved that if R() satisfies nontrivial polynomial identities, then so does R. This answers affirmatively a problem raised in Bergen and Grzeszczuk [2] by removing the assumption on the algebraicity of .Mathematics Subject Classification (2000): 16W20, 16W25, 16W55Members of Mathematics Division, National Center for Theoretical Sciences at Taipei.Acknowledgement The authors are thankful to the referee for her/his useful suggestions and comments. This research was supported by the National Science Council of Taiwan. 相似文献
2.
Giuseppe Zampieri 《manuscripta mathematica》2005,116(4):397-400
We prove that a small analytic disc A attached to a pseudoconvex submanifold M of and which shares a conormal with M at some boundary point, is in fact contained in M. The proof uses an argument of reduction to a hypersurface by a symplectic complex transformation. The result is classical in case codM=1 (cf. e.g. [4]); it is a consequence of Hopfs Lemma applied to a plurisubharmonic defining function of M as in [5]. It was already generalized to the higher codimension in [8] but under the additional assumption, in the present paper, that A has an analytic lift A* in T*X attached to T*MX (i.e. A has defect 1 in the terminology of [6], [7]). 相似文献
3.
Yūji Sakai 《Analysis Mathematica》1984,10(4):301-310
. (R)
–
–
fg(y)h(x–y) dx dy
–
–
f
^
(x)g
^
(y)h
^
(x–y)dx dy (f,g0) —:f×gf
^
×g
^(f,g 0) f^ g^ f g -, X — . , - f
1f
2 , f
1
^
×gf
2×g 0g. . 相似文献
4.
Let denote the ring of power sums, i.e. complex functions of the form for some and iA, where is a multiplicative semigroup. Moreover, let We consider Diophantine inequalities of the form where >1 is a quantity depending on the dominant roots of the power sums appearing as coefficients in F(n,y), and show that all its solutions have y parametrized by some power sums from a finite set. This is a continuation of the work of Corvaja and Zannier [4–6] and of the authors [10, 18] on such problems.Mathematics Subject Classification (2000):11D45,11D61Revised version: 6 May 2004 相似文献
5.
We consider the Navier–Stokes equations for compressible isentropic flow in the steady three-dimensional case. The pressure and the kinetic energy are estimated uniformly in Lq with being the density. This is an improvement of known estimates in the case Mathematics Subject Classification (2000): 35Q30, 76N10 相似文献
6.
А. В. Резцов 《Analysis Mathematica》1995,21(2):129-135
Q (.. , L). Q . P(Sr(2)) — 2 (S
r(2) (r — ). , M(P(S
r(m=sup{t(·)t(·)1:t P(S
r(2)),t 0}. , /4+(1)M(P(S
r(2)))/r
215/17+(1)(r+). (Q), Q L. 相似文献
7.
V. A. Slousch 《Journal of Mathematical Sciences》2003,115(2):2272-2278
Let A be a self-adjoint elliptic second-order differential operator, let (, ) be an inner gap in the spectrum of A, and let B(t) = A + tW
*
W, where W is a differential operator of higher order. Conditions are obtained under which the spectrum of the operator B(t) in the gap (, ) is either discrete, or does not accumulate to the right-hand boundary of the spectral gap, or is finite. The quantity N(, A, W, ), (, ), > 0 (the number of eigenvalues of the operator B(t) passing the point (, ) as t increases from 0 to ) is considered. Estimates of N(, A, W, ) are obtained. For the perturbation W
*
W of a special form, the asymptotics of N(, A, W, ) as + is given. Bibliography: 5 titles. 相似文献
8.
We consider a Diophantine inequality:on the set of formal Laurent series of negative degree. We show that under these two conditions: (i) qn(n) is a monotone non-increasing and (ii) nqn(n)=, a central limit theorem holds for the number of solutions. The proof is based on the construction of a non-stationary one dependent process associated with the Diophantine inequality.Mathematics Subject Classification (2000): 11J61, 11K60 相似文献
9.
We prove the global Hölder continuity of convex solutions uC3() of the equation of prescribed positive Gauss curvature in a bounded convex domain with C1, for some (0,1]. We also obtain better regularity for the trace of u on . In the special case =1 we show that and u|C0,2/3(). We also investigate the global continuity of solutions in C1 domains and construct an example showing that global continuity need not hold in general convex domains.Supported by an Australian Research Council Senior Fellowship.Mathematics Subject Classification (2000): Primary 35J60; Secondary 53A05, 53C42 相似文献
10.
Gerold Alsmeyer 《Mathematical Methods of Operations Research》1986,30(3):A111-A134
Let
1, 2, ... be a sequence of i.i.d. random variables with positive mean
and finite variance
and letr(b), b0, be real numbers tending to 0 asb . Definings
n=1+...+n andS
n=Sn(b)=sn+r(b)n, the stopping time =(b)=inf {n>/1:Sn >b} whereb=b(b) , will be considered with special regard to the excess over the boundaryR
b=s+r(b)–b. It turns out that the limiting distribution ofR
b is the same as in the caser(b)0 for allb. Proving this, Blackwell's renewal theorem and its integral version have to be established first in the above stated situation. Finally, an expansion ofE to vanishing terms asb will be provided and applied to some examples arising in economics.
Zusammenfassung Seien 1, 2, ... unabhängige identisch verteilte Zufallsgrößen mit positivem Erwartungswert und endlicher Varianz sowier(b), b0, reelle Zahlen mitr(b)0 für b. Sei ferners 1, s2, ... der zugehörige Summenprozeß,S n= Sn(b)=sn+r(b)n fürn1 und =(b)=inf {n1: Sn>b, wobeib=b(b) fürb . Es wird gezeigt, daß die asymptotische Verteilung des ExzessesR b=s +r(b) –b mit der im Fallr(·)0 übereinstimmt. Dazu werden sowohl das Blackwellsche Erneuerungstheorem als auch seine Integralversion in der vorher beschriebenen parameterabhängigen Situation geeignet formuliert und bewiesen. Als Folgerung ergibt sich dann eine asymptotische Entwicklung vonE(b) fürb bis zu Termen o(1). Anh- and einiger Beispiele aus dem ökonomischen Bereich wird schließlich noch aufgezeigt, wo Approximationen fürE(b) von Interesse sein können.相似文献
11.
Ch. Pommerenke 《Analysis Mathematica》1977,3(4):291-297
f . , , — , A f f(). , , f() 0 . , , ,A , f . , f() - f() . , , . (1976) ( ¦f(z)¦<1) . . (1969) ( ). 相似文献
12.
We give a formulation, via (1, –1) matrices, of Mathon's construction for conference matrices and derive a new family of conference matrices of order 592t+1 + 1,t 0. This family produces a new conference matrix of order 3646 and a new Hadamard matrix of order 7292. In addition we construct new families of Hadamard matrices of orders 692t+1 + 2, 1092t+1 + 2, 8499
t
,t 0;q
2(q + 3) + 2 whereq 3 (mod 4) is a prime power and 1/2(q + 5) is the order of a skew-Hadamard matrix); (q + 1)q
29
t
,t 0 (whereq 7 (mod 8) is a prime power and 1/2(q + 1) is the order of an Hadamard matrix). We also give new constructions for Hadamard matrices of order 49
t
0 and (q + 1)q
2 (whereq 3 (mod 4) is a prime power).This work was supported by grants from ARGS and ACRB.Dedicated to the memory of our esteemed friend Ernst Straus. 相似文献
13.
Guyan Robertson 《K-Theory》2001,22(3):251-269
Let be a torsionfree lattice in G=PGL(n+1,
, where n 1 and
is a nonArchimedean local field. Then acts on the Furstenberg boundary G/P, where P is a minimal parabolic subgroup of G. The identity element I in the crossedproduct C
*algebra C(G/P) generates a class [I] in the K
0 group of C(G/P) . It is shown that [I] is a torsion element of K
0 and there is an explicit bound for the order of [I]. The result is proved more generally for groups acting on affine buildings of type Ã
n. For n=1, 2 the Euler–Poincaré characteristic () annihilates the class [I]. 相似文献
14.
We give a sufficient condition on a closed subset R
n
for the weighted Poincaré inequality (1.5) below to be valid. As an application, we prove that, for any 2p<n and any such closed subset R
n
, if uC
1( , N) W
1,p
(, N) is a stationary p-harmonic map such that |Du|
p
(x) dx is sufficiently small, then uC
1(, N). This extends previously known removal singularity theorems for p-harmonic maps.
Mathematics Subject Classification (2000):58E20, 58J05, 35J60This revised version was published online in September 2003 with a corrected date of receipt of the article. 相似文献
15.
Summary. We consider the Uzawa method to solve the stationary Stokes equations discretized with stable finite elements. An iteration step consists of a velocity update un+1 involving the (augmented Lagrangian) operator ––÷ with 0, followed by the pressure update pn+1=pn–div un+1, the so-called Richardson update. We prove that the inf-sup constant satisfies 1 and that, if =1+–1, the iteration converges linearly with a contraction factor 2-1(2-) provided 0<<2. This yields the optimal value = regardless of .Mathematics Subject Classification (1991): 65N12, 65N15Partially supported by NSF Grant DMS-9971450Partially supported by NSF Grants DMS-9971450 and DMS-0204670Revised version received September 30, 2003 相似文献
16.
Let be a G-symmetric graph whose vertex set admits a nontrivial G-invariant partition with block size v. Let
be the quotient graph of relative to and [B,C] the bipartite subgraph of induced by adjacent blocks B,C of . In this paper we study such graphs for which
is connected, (G, 2)-arc transitive and is almost covered by in the sense that [B,C] is a matching of v-1 2 edges. Such graphs arose as a natural extremal case in a previous study by the author with Li and Praeger. The case
K
v+1 is covered by results of Gardiner and Praeger. We consider here the general case where
K
v+1, and prove that, for some even integer n 4,
is a near n-gonal graph with respect to a certain G-orbit on n-cycles of
. Moreover, we prove that every (G, 2)-arc transitive near n-gonal graph with respect to a G-orbit on n-cycles arises as a quotient
of a graph with these properties. (A near n-gonal graph is a connected graph of girth at least 4 together with a set of n-cycles of such that each 2-arc of is contained in a unique member of .) 相似文献
17.
We prove a local limit theorem (LLT) on Cramer-type large deviations for sums S
V
=
t
V (
t
), where
t
, t Z
, 1, is a Markov Gaussian random field, V Z
, and is a bounded Borel function. We get an estimate from below for the variance of S
V
and construct two classes of functions , for which the LLT of large deviations holds. 相似文献
18.
D. Plachky 《Journal of Theoretical Probability》1992,5(3):577-584
Let (,A,P) denote some probability space and some sub--algebra ofA. It is shown that there exists a semiregular versionQ
(A),A, , of the conditional distributionP(A|), AA, i.e., Q
(A), (AA fixed) is andAQ
(A),AA ( fixed), is a probability charge satisfyingQ
(N)=0, , for allP-zero setsN, if and only ifL
1(,P|) has a lifting, which exists for any sub--algebra ofA ifL
1(,A
P) is separable. Separability ofL
1(,A,P) implies also the existence of a strongly semiregular versionQ
(A),A, , ofP(A|), A , i.e., Q
(A), (AA fixed), is -measurable andAQ
(A),A ( fixed), is a probability charge. Furthermore,P can be written as P
1+(1–)P
2, 01, whereP
1 are probability measures onA such thatP
1(A|),AA, has a semiregular version vanishing for anyP-zero setN andP
2 is singular with respect to any probability measure onA of the type ofP
1. In the case 0<<1 the probability measuresP
j
,j=1, 2, are uniquely determined. The decomposition can be carried over to the case, where the additional condition thatQ
(N)=0 for all and anyP-zero setN is valid, is omitted respectively semiregularity is replaced by (i) strong semiregularity, or (ii) classical regularity. In the last mentioned case (ii) the decomposition is multiplicative. 相似文献
19.
Il existe un théorème de changement de base pour les foncteurs dérivés Ext (voir par exemple [5]) et le but de cet article est, dans un premier temps, de démontrer un théorème analogue pour les foncteurs dérivés Tor. Il donne un isomorphisme de la forme Tor*(F,R(G)) Tor*(L(F),G), où (L,R) est un couple de foncteurs obtenus à partir dun - bimodule, F un op-module et G un -module. On définit ensuite la notion de catégorie croisée, qui donne naissance à des exemples de ce type. Le théorème de Pirashvili et Richter sur lhomologie de Hochschild et lhomologie cyclique démontré dans [6] en est une conséquence immédiate.Mathematics Subject Classification (2000): 18G15, 16E40 相似文献
20.
Reverse Functional Inequalities and Their Applications to Nonlinear Elliptic Boundary Value Problems
We establish some reverse inequalities. We give applications to nonlinear elliptic boundary value problems containing a parameter which have two branches of solutions u
(0) and U
(>0) of which the first is continuous at the origin and the second increases indefinitely as 0. 相似文献