摘要:

AbstractGlobal intersection theories for smooth algebraic varieties via products in appropriate Poincaré duality theories are obtained. We assume given a (twisted) cohomology theoryH* having a cup product structure and we consider the ℋ︁‐ cohomology functorX ↝ H#Zar(X, ℋ︁*) whereℋ︁*is the Zariski sheaf associated toH*. We show that the ℋ︁‐ cohomology rings generalize the classical “intersection rings” obtained via rational or algebraic equivalences. Several basic properties e. g. Gysin maps, projection formula and projective bundle decomposition, of ℋ︁‐ cohomology are obtained. We therefore obtain, forXsmooth, Chern classescP, i:Ki(X)→ Hp‐i(X,ℋ︁p) from the QuillenK‐theory to ℋ︁‐ cohomologies according to Gillet and Grothendieck. We finally obtain the “blow‐up formula”whereX′is the blow–up ofXsmooth, along a closed smooth subsetZof pure codimension c. Singular cohomology of associated analityc space, étale cohomology, de Rham and D

ISSN:0025-584X    

DOI:10.1002/mana.19971840102

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractWe compute the following upper bounds for the maximal arithmetic genusPa(d,t) over all locally Cohen ‐ Macaulay space curves of degreed, which are not contained in a surface of degreeThese bounds are sharp for t ≤ 4 abd any d

ISSN:0025-584X    

DOI:10.1002/mana.19971840103

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractAn anisotropic pseudo — differential calculus aimed at solving parabolic differential and pseudo — differential equations in terms of Volterra pseudo–differential operators was studied by Piriou for spatial variables on a closedC∞– manifold. Such a program also makes sense when the spatial variables run over a manifold with edges. Our approach deals with this case. It covers, in particular, manifolds with conical singularities. The main point of the present paper is the anisotropic edge pseudo — differential calculus, obtained as a substructure of our corresponding abstract anisotropic edge calculus with operator — v

ISSN:0025-584X    

DOI:10.1002/mana.19971840104

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractFür gewisse quadratische Erweiterungen wird ein geometrisch interpretierbares Kriterium dafür angegeben, ob ein ungerades Primelement von verzweigt, zerfällt oder träge

ISSN:0025-584X    

DOI:10.1002/mana.19971840105

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractLet (sj)∞j=0be a sequence of real numbers such that the Hankel matrices (si+j)∞0, (Si+j+i)∞0have finite numbers of negative eigenvalues. The indefinite moment problem with the momentsSj(j= 0,1,2, …) and the corresponding Stieltjes string are investigated. We use the approach via the Kreîn — Langer extension theory of symmetric operators in spaces with indefinite metric. In the framework of this approach a description of L– resolvents of a class of symmetric operators in Kreîn space and a simple formula for the calculation of the L– resolvent matrix in terms of boundary oper

ISSN:0025-584X    

DOI:10.1002/mana.19971840106

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractWe prove that for any Köthe matrices a andbifT : λ1(α) → λ0(b) maps bounded sets into relatively compact sets, thenTfactorizes through a Fréchet Montel space. This is a consequence of a given description of those compact subsets in a coechelon spacek∞(v) of type oo which are contained in an absolutely convex hull of a null sequence. An example of a compact set which is not of that form

ISSN:0025-584X    

DOI:10.1002/mana.19971840107

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractGiven a finite fieldFqof orderq, a fixed polynomialgin –Fq[X] of positive degree, and two elementsuandvin the ring of polynomials inR=Fq[X]/gFq[X], the question arises: How many pairs (a, 6) are there inR×Rso thatab 1 modgand so that a is close touwhilebis close tov? The answer is, about as many as one would expect. That is, there are no favored regions inR×Rwhere inverse pairs cluster. The error term is quite sharp in most cases, being comparable to what would happen with random distribution of pairs. The proof uses Kloosterman sums and counting arguments. The exceptional cases involve fields of characteristic 2 and composite values ofg. Even then the error term obtained is nontrivial. There is no computational evidence that inverses are in fact less evenly distributed in this case, ho

ISSN:0025-584X    

DOI:10.1002/mana.19971840108

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractWe are interested in finding the velocity distribution at the wings of an aeroplane. Within the scope of a three — dimensional linear theory we analyse a model which is formulated as a mixed screen boundary value problem for the Helmholtz equation (Δ +k2)Φ = 0 in ℝ3\swhere Φ denotes the perturbation velocity potential, induced by the presence of the wings ands:=LUWwith the projectionLof the wings onto the (x,y)‐plane and the wake W.Not all Cauchy data are given explicitly onL, respectivelyW. These missing Cauchy data depend on the wing circulation Γ· Γ has to be fixed by the Kutta–Joukovskii condition: Λ Φ should be finite near the trailing edgextofL. To fulfil this condition in a way that all appearing terms can be defined mathematically exactly and belong to spaces which are physically meaningful, we propose to fix Γ by the condition of vanishing stress intensity factors of Φ nearxtup to a certain order such that ΛΦ|xtϵW2ϵ(xt)⊂L2(xt),ϵ>0.In the two–dimensional case, and ifLis the left half–plane in ℝ2, we have an explicit formula to calculate Γ and we can co

ISSN:0025-584X    

DOI:10.1002/mana.19971840109

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractAn analog to the Gleason theorem for measures on logics of projections in indefinite metric spaces is proved.

ISSN:0025-584X    

DOI:10.1002/mana.19971840110

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY

摘要:

AbstractThe norm of the inverse operator of ϵA + B‐ λIbetween the Besov spacesB ∞s, ∞ (Ω) andBt∞,∞(Ω) is estimated, whereAandBare uniformly elliptic operators with smooth coefficients and Dirichlet boundary conditions,Ais of order 2m, Bof order 2m, m>m'. The estimate holds for negativet. The Besov spaceB ∞s, ∞ (Ω) reduces to the space of Hölder continuous functionsCs(Ω) ifs<0 is non – integer.In particular, it is shown thatAϵgenerates an analytic semigroup inB ∞s, ∞ (Ω),sϵ (‐1,0), if Ω = ℝnor ℝ +nandA,Bare constant coe

ISSN:0025-584X    

DOI:10.1002/mana.19971840111

出版商:WILEY‐VCH Verlag    

年代:1997

数据来源: WILEY