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1.
SecondOrderParallelTensorsonP-SasakianManifolds¥DebasishTarafdarandU.C.De(DepartmentofMathematics,UniversityofKalyani,Kalyani...  相似文献   

2.
Sub┐productClasesofl┐GroupsTongDaorong(仝道荣)(DepartmentofMathematics,HehaiUniversity,Nanjing,210024)AbstractAclassofl-groupsis...  相似文献   

3.
TorsionClasesandTorsionValueSelectorsofhl┐groupsTongDaorong(仝道荣)(DepartmentofMathematics,HehaiUniversity,Nanjing,210024)Miche...  相似文献   

4.
邱瑞峰 《东北数学》2000,16(4):484-490
§ 1.Introduction LetMbeacompact 3 manifold .IfthereisaproperlyembeddedclosedsurfaceSinMwhichseparatesMintotwocompressionbodiesH1andH2 ,thenMcanbewrittenasM =H1∪SH2 .ThisstructureonMiscalledaHeegaardsplittingofMandSisasplittingsurface .H1∪SH2 issaidtobereducible…  相似文献   

5.
TheLimitDistributionofSomePPCMStatisticswithEnoughHighDimensionsandLargeSampleSizeChengPing(成平)(InstituteofSystemsScience,Aca...  相似文献   

6.
TheLimitDistributionofPPCram︺r┐vonMisesNormalityTestStatisticsforHighDimensionandLargeSampleSizeLiuYixing(刘义兴)andChengPing(成平...  相似文献   

7.
ChernClassesinBivariantTheoryDefinitionsofBrasseletandofSabbah¥JianyiZHOU(SiGmACNRS,CIRMLuminyCase916,F-13288MarseilleCedex9;...  相似文献   

8.
柏传志 《数学季刊》1998,13(3):23-28
§1. IntroductionSiddiqiandAnsari[4]developediterativealgorithmsforfindingapproximatesolutiontonewclassesofquasivariationalinequalitiesinHilbertspaces,HassouniandMoudafi[1]extendthemainideasofpaper[4]tomoregeneralcases,whichconsideredaclassofvariation…  相似文献   

9.
SomeCharacterizationsofaClassof M-matricesLiWen(黎稳)andZhangMoucheng(张谋成)(DepartmentofMathematics,SouthChinaNormalUviversity,G...  相似文献   

10.
The Structure of NBe—rpp Semigroups   总被引:2,自引:0,他引:2  
郭小江 《东北数学》2000,16(4):398-404
§ 1.IntroductionandMainResults AsemigroupSiscalledanrppsemigroupifallprincipalrightidealsaS1(a∈S)ofS ,regardedasanS1 system ,areprojective (see,[1 ]and [2 ] ) .AsemigroupSisanrppsemigroupifandonlyifforalla∈S ,thesetMa ={e∈E S1a Seand ( x ,y∈S1)ax=ay ex=ey}isnonempty ,whereE …  相似文献   

11.
LetI be a σ-ideal on a Polish space such that each set fromI is contained in a Borel set fromI. We say thatI fails to fulfil theΣ 1 1 countable chain condition if there is aΣ 1 1 equivalence relation with uncountably many equivalence classes none of which is inI. Assuming definable determinacy, we show that if the family of Borel sets fromI is definable in the codes of Borel sets, then eachΣ 1 1 set is equal to a Borel set modulo a set fromI iffI fulfils theΣ 1 1 countable chain condition. Further we characterize the σ-idealsI generated by closed sets that satisfy the countable chain condition or, equivalently in this case, the approximation property forΣ 1 1 sets mentioned above. It turns out that they are exactly of the formMGR(F)={A : ∀FF AF is meager inF} for a countable family F of closed sets. In particular, we verify partially a conjecture of Kunen by showing that the σ-ideal of meager sets is the unique σ-ideal onR, or any Polish group, generated by closed sets which is invariant under translations and satisfies the countable chain condition. Research partially supported by NSF grant DMS-9317509.  相似文献   

12.
 The paper establishes lower bounds on the provability of 𝒟=NP and the MRDP theorem in weak fragments of arithmetic. The theory I 5 E 1 is shown to be unable to prove 𝒟=NP. This non-provability result is used to show that I 5 E 1 cannot prove the MRDP theorem. On the other hand it is shown that I 1 E 1 proves 𝒟 contains all predicates of the form (∀i≤|b|)P(i,x)^Q(i,x) where ^ is =, <, or ≤, and I 0 E 1 proves 𝒟 contains all predicates of the form (∀ib)P(i,x)=Q(i,x). Here P and Q are polynomials. A conjecture is made that 𝒟 contains NLOGTIME. However, it is shown that this conjecture would not be sufficient to imply 𝒟=N P. Weak reductions to equality are then considered as a way of showing 𝒟=NP. It is shown that the bit-wise less than predicate, ≤2, and equality are both co-NLOGTIME complete under FDLOGTIME reductions. This is used to show that if the FDLOGTIME functions are definable in 𝒟 then 𝒟=N P. Received: 13 July 2001 / Revised version: 9 April 2002 / Published online: 19 December 2002 Key words or phrases: Bounded Arithmetic – Bounded Diophantine Complexity  相似文献   

13.
LetI be a union of finitely many closed intervals in [−1, 0). LetI be a single interval of the form [−1, −a] chosen to have the same logarithmic length asI. LetD be the unit disc. Then, Beurling [8] has shown that the harmonic measure of the circle ∂D at the origin in the slit discD/I is increased ifI is replaced byI . We prove a number of cognate results and extensions. For instance, we show that Beurling's result remains true if the intervals inI are not just one-dimensional, but if they in fact constitute polar rectangles centred on the negative real axis and having some fixed constant angular width. In doing this, we obtain a new proof of Beurling's result. We also discuss a conjecture of Matheson and Pruss [25] and some other open problems. Much of the present paper has been adapted from Chapter IV of the author's doctoral dissertation. The research was partially supported by Professor J. J. F. Fournier's NSERC Grant #4822.  相似文献   

14.
Abstract We improve estimates for the distribution of primitive λ-roots of a composite modulus q yielding an asymptotic formula for the number of primitive λ-roots in any interval I of length ∣I∣ ≫ q 1/2+∈. Similar results are obtained for the distribution of ordered pairs (x, x −1) with x a primitive λ-root, and for the number of primitive λ-roots satisfying inequalities such as |xx −1| ≤ B. (Dedicated to Professor Wang Yuan on the occasion of his 75th birthday) *Project supported by the National Natural Science Foundation of China (No.19625102) and the 973 Project of the Ministry of Science and Technology of China.  相似文献   

15.
A. Mazzoleni 《K-Theory》2005,35(3-4):199-211
In this paper we compute the group H2(SL2(F)), for F an infinite field. In particular, using some techniques from homological algebra developed by Hutchinson [Hutchinson, K: K-Theory 4 (1990), 181–200], we give a new proof of the following theorem obtained by [Su2]: The group H2(SL2, (F)) is the fiber product of λ*:K2(F)→ I2(F)/I3(F) and σ: I2(F) → I2(F)/I3(F) where λ* and σ map onto I2(F)/I3(F). (Received: February 2003)  相似文献   

16.
For a given idealI of a commutative ringA, B=A/I, the vanishing of the second André-Quillen (co)homology functorH 2 (A, B, δ) is characterized in terms of the canonical homomorphism α:S(I)→R(I) from the symmetric algebra of the idealI onto its Rees algebra. This is done by introducing a Koszul complex that characterizes commutative graded algebras which are symmetric algebras.

This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag.  相似文献   

17.
Fix integers n, x, k such that n≥3, k>0, x≥4, (n, x)≠(3, 4) and k(n+1)<( n n+x ). Here we prove that the order x Veronese embedding ofP n is not weakly (k−1)-defective, i.e. for a general SP n such that #(S) = k+1 the projective space | I 2S (x)| of all degree t hypersurfaces ofP n singular at each point of S has dimension ( n /n+x )−1− k(n+1) (proved by Alexander and Hirschowitz) and a general F∈| I 2S (x)| has an ordinary double point at each PS and Sing (F)=S. The author was partially supported by MIUR and GNSAGA of INdAM (Italy).  相似文献   

18.
Summary LetR be a Cohen-Macaulay ring andI an unmixed ideal of heightg which is generically a complete intersection and satisfiesI (n)=In for alln≥1. Under what conditions will the Rees algebra be Cohen-Macaulay or have good depth? A series of partial answers to this question is given, relating the Serre condition (S r ) of the associated graded ring to the depth of the Rees algebra. A useful device in arguments of this nature is the canonical module of the Rees algebra. By making use of the technique of the fundamental divisor, it is shown that the canonical module has the expected form: ω R[It] ≅(t(1−t) g−2). The third author was partially supported by the NSF This article was processed by the author using theLaTex style filecljour1 from Springer-Verlag.  相似文献   

19.
LetH be the algebra of bounded analytic functions in the unit diskD. LetI=I(f 1,...,f N) be the ideal generated byf 1,...,f NH andJ=J(f 1,...,f N) the ideal of the functionsf∈H for which there exists a constantC=C(f) such that |f(z)|≤C(|f 1 (z)|+...;+|f N (z)|),zD. It is clear that , but an example due to J. Bourgain shows thatJ is not, in general, in the norm closure ofI. Our first result asserts thatJ is included in the norm closure ofI ifI contains a Carleson-Newman Blaschke product, or equivalently, if there existss>0 such that
Our second result says that there is no analogue of Bourgain's example in any Hardy spaceH p, 1≤p<∞. More concretely, ifg∈H p and the nontangential maximal function of belongs toL p (T), theng is in theH p-closure of the idealI. Both authors are supported in part by DGICYT grant PB98-0872 and CIRIT grant 1998SRG00052.  相似文献   

20.
We optimise a distribution of two isotropic materials α I and β I (α < β) occupying the given body in R d . The optimality is described by an integral functional (cost) depending on temperatures u 1, . . . , u m of the body obtained for different source terms f 1, . . . ,f m with homogeneous Dirichlet boundary conditions. The relaxation of this optimal design problem with multiple state equations is needed, introducing the notion of composite materials as fine mixtures of different phases, mathematically described by the homogenisation theory. The necessary conditions of optimality are derived via the Gateaux derivative of the cost functional. Unfortunately, there could exist points in which necessary conditions of optimality do not give any information on the optimal design. In the case m < d we show that there exists an optimal design which is a rank-m sequential laminate with matrix material α I almost everywhere on Ω. Contrary to the optimality criteria method, which is commonly used for the numerical solution of optimal design problems (although it does not rely on a firm theory of convergence), this result enables us to effectively use classical gradient methods for minimising the cost functional.   相似文献   

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