共查询到20条相似文献,搜索用时 31 毫秒
1.
V.M. Petrogradsky 《Journal of Pure and Applied Algebra》2007,208(3):1137-1158
We define the multiple zeta function of the free Abelian group Zd as
ζZd(s1,…,sd)=∑|Zd:H|<∞α1(H)−s1?αd(H)−sd, 相似文献
2.
B.A.F. Wehrfritz 《Journal of Pure and Applied Algebra》2007,209(2):301-309
Let D be a division ring of finite degree d and let n be a positive integer. If G is any soluble subgroup of , we prove that G has derived length at most
9+log2d+(11/3)log2n 相似文献
3.
Philippe Bonnet 《Bulletin des Sciences Mathématiques》2006,130(4):312-329
Let C be a complex affine reduced curve, and denote by H1(C) its first truncated cohomology group, i.e. the quotient of all regular differential 1-forms by exact 1-forms. First we introduce a nonnegative invariant μ′(C,x) that measures the complexity of the singularity of C at the point x, and we establish the following formula:
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Let (X,x0) be any one-pointed compact connected Riemann surface of genus g, with g≥3. Fix two mutually coprime integers r>1 and d. Let MX denote the moduli space parametrizing all logarithmic -connections, singular over x0, on vector bundles over X of degree d. We prove that the isomorphism class of the variety MX determines the Riemann surface X uniquely up to an isomorphism, although the biholomorphism class of MX is known to be independent of the complex structure of X. The isomorphism class of the variety MX is independent of the point x0∈X. A similar result is proved for the moduli space parametrizing logarithmic -connections, singular over x0, on vector bundles over X of degree d. The assumption r>1 is necessary for the moduli space of logarithmic -connections to determine the isomorphism class of X uniquely. 相似文献
6.
In this paper, we prove a sufficient and necessary condition for the stability of the equilibrium x=x′=0 of the damped oscillator with damping changing sign
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The hypersurfaces of degree d in the projective space Pn correspond to points of PN, where . Now assume d=2e is even, and let X(n,d)⊆PN denote the subvariety of two e-fold hyperplanes. We exhibit an upper bound on the Castelnuovo regularity of the ideal of X(n,d), and show that this variety is r-normal for r?2. The latter result is representation-theoretic, and says that a certain GLn+1-equivariant morphism
Sr(S2e(Cn+1))→S2(Sre(Cn+1)) 相似文献
9.
Let (X,D) be an ?-pointed compact Riemann surface of genus at least two. For each point x∈D, fix parabolic weights such that . Fix a holomorphic line bundle ξ over X of degree one. Let PMξ denote the moduli space of stable parabolic vector bundles, of rank two and determinant ξ, with parabolic structure over D and parabolic weights . The group of order two line bundles over X acts on PMξ by the rule E∗⊗L?E∗⊗L. We compute the Chen-Ruan cohomology ring of the corresponding orbifold. 相似文献
10.
Satoshi Murai 《Journal of Pure and Applied Algebra》2008,212(6):1321-1336
Let S=K[x1,…,xn] be a standard graded polynomial ring over a field K. In this paper, we show that the lex-plus-powers ideal has the largest graded Betti numbers among all Borel-plus-powers monomial ideals with the same Hilbert function. In addition in the case of characteristic 0, by using this result, we prove the lex-plus-powers conjecture for graded ideals containing , where p is a prime number. 相似文献
11.
Morou Amidou 《Linear algebra and its applications》2008,429(7):1687-1698
We present a new and simple algorithm for completion of unimodular vectors with entries in a multivariate Laurent polynomial ring over an infinite field K. More precisely, given n?3 and a unimodular vector V=t(v1,…,vn)∈Rn (that is, such that 〈v1,…,vn〉=R), the algorithm computes a matrix M in Mn(R) whose determinant is a monomial such that MV=t(1,0,…,0), and thus M-1 is a completion of V to an invertible matrix. 相似文献
12.
Xiongping Dai 《Journal of Differential Equations》2011,250(9):3584-3629
Let {A1,…,AK}⊂Cd×d be arbitrary K matrices, where K and d both ?2. For any 0<Δ<∞, we denote by the set of all switching sequences u=(λ.,t.):N→{1,…,K}×R+ satisfying tj−tj−1?Δ and
13.
We find a sufficient condition that is not level based on a reduction number. In particular, we prove that a graded Artinian algebra of codimension 3 with Hilbert function cannot be level if hd≤2d+3, and that there exists a level O-sequence of codimension 3 of type for hd≥2d+k for k≥4. Furthermore, we show that is not level if , and also prove that any codimension 3 Artinian graded algebra A=R/I cannot be level if . In this case, the Hilbert function of A does not have to satisfy the condition hd−1>hd=hd+1.Moreover, we show that every codimension n graded Artinian level algebra having the Weak-Lefschetz Property has a strictly unimodal Hilbert function having a growth condition on (hd−1−hd)≤(n−1)(hd−hd+1) for every d>θ where
h0<h1<<hα==hθ>>hs−1>hs.