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991.
Brian Conrad 《Compositio Mathematica》1999,119(3):239-326
Let A be a complete characteristic (0,p) discrete valuation ring with absolute ramification degree e and a perfect residue field. We are interested in studying the category FF
A' of finite flat commutative group schemes over A withp-power order. When e= 1, Fontaine formulated the purely linear algebra notion of a finite Honda system over A and constructed an anti-equivalence of categories betweenineFF
A'> and the category of finite Honda systems over A when p> 2. We generalize this theory to the case e – 1. 相似文献
992.
Milan Kučera 《Czechoslovak Mathematical Journal》1999,49(3):449-474
Variational inequalities
are studied, where K is a closed convex cone in
, 3, B
is a × matrix, G is a small perturbation, a real parameter. The assumptions guaranteeing a Hopf bifurcation at some 0 for the corresponding equation are considered and it is proved that then, in some situations, also a bifurcation of periodic solutions to our inequality occurs at some I 0. Bifurcating solutions are obtained by the limiting process along branches of solutions to penalty problems starting at 0 constructed on the basis of the Alexander-Yorke theorem as global bifurcation branches of a certain enlarged system. 相似文献
993.
Let ( G) be a flag-transitive c.c*-geometry whose point-stabilizer is not an affine group. We list all known examples and show that, if (, G) is a minimal unknown example, then G is an almost simple group and the commutator subgroup G is a simple group of Lie type. 相似文献
994.
Tatsuya Maruta 《Geometriae Dedicata》1999,74(3):305-311
Any {f,r- 2+s; r,q}-minihyper includes a hyperplane in PG(r, q) if fr-1 + s 1 + q – 1 for 1 s q – 1, q 3, r 4, where i = (qi + 1 – 1)/ (q – 1 ). A lower bound on f for which an {f, r – 2 + 1; r, q}-minihyper with q 3, r 4 exists is also given. As an application to coding theory, we show the nonexistence of [ n, k, n + 1 – qk – 2 ]q codes for k 5, q 3 for qk – 1 – 2q – 1 < n qk – 1 – q – 1 when k > q –
q - \sqrt q + 2$$
" align="middle" border="0">
and for
when
, which is a generalization of [18, Them. 2.4]. 相似文献
995.
Hauke Klein 《Geometriae Dedicata》1999,77(3):271-277
We consider a four-dimensional compact projective plane
whose collineation group is six-dimensional and solvable with a nilradical N isomorphic to Nil×R, where Nil denotes the three-dimensional, simply connected, non-Abelian, nilpotent Lie group. We assume that fixes a flag p W, acts transitively on
and fixes no point in the set W\p. Under these conditions, we will prove that either contains a three-dimensional group of elations or acts doubly transitively on
. 相似文献
996.
Jin-Ming Chao 《Geometriae Dedicata》1999,74(1):91-94
Let m2(n,q), m2(n,q) be, respectively, the maximum value, the second largest value of k for which there exists a complete k-cap in PG(n,q). In this paper, the known upper bound on m2(3,q), q even, q 8, is improved. This new upper bound on m2(3,q) is then used to improve the upper bounds on m2(n,q), q even, q 8 and n 4. 相似文献
997.
Sheila Sundaram 《Journal of Algebraic Combinatorics》1999,9(3):251-269
We present a class of subposets of the partition lattice
n
with the following property: The order complex is homotopy equivalent to the order complex of
n
– 1, and the S
n
-module structure of the homology coincides with a recently discovered lifting of the S
n
– 1-action on the homology of
n
– 1. This is the Whitehouse representation on Robinson's space of fully-grown trees, and has also appeared in work of Getzler and Kapranov, Mathieu, Hanlon and Stanley, and Babson et al.One example is the subposet P
n
n
– 1 of the lattice of set partitions
n
, obtained by removing all elements with a unique nontrivial block. More generally, for 2 k n – 1, let Q
n
k
denote the subposet of the partition lattice
n
obtained by removing all elements with a unique nontrivial block of size equal to k, and let P
n
k
=
i = 2
k
Q
n
i
. We show that P
n
k
is Cohen-Macaulay, and that P
n
k
and Q
n
k
are both homotopy equivalent to a wedge of spheres of dimension (n – 4), with Betti number
. The posets Q
n
k
are neither shellable nor Cohen-Macaulay. We show that the S
n
-module structure of the homology generalises the Whitehouse module in a simple way.We also present a short proof of the well-known result that rank-selection in a poset preserves the Cohen-Macaulay property. 相似文献
998.
Questions of approximative nature are considered for a space of functions L
p(G, ), 1 p , defined on a locally compact abelian Hausdorff group G with Haar measure . The approximating subspaces which are analogs of the space of exponential type entire functions are introduced. 相似文献
999.
Robert Gilmer William Heinzer Moshe Roitman 《Proceedings of the American Mathematical Society》1999,127(11):3141-3151
Suppose is a maximal ideal of a commutative integral domain and that some power of is finitely generated. We show that is finitely generated in each of the following cases: (i) is of height one, (ii) is integrally closed and , (iii) is a monoid domain over a field , where is a cancellative torsion-free monoid such that , and is the maximal ideal . We extend the above results to ideals of a reduced ring such that is Noetherian. We prove that a reduced ring is Noetherian if each prime ideal of has a power that is finitely generated. For each with , we establish existence of a -dimensional integral domain having a nonfinitely generated maximal ideal of height such that is -generated.
1000.
Susanne C. Brenner. 《Mathematics of Computation》1999,68(225):25-53
We consider nonconforming multigrid methods for symmetric positive definite second and fourth order elliptic boundary value problems which do not have full elliptic regularity. We prove that there is a bound () for the contraction number of the -cycle algorithm which is independent of mesh level, provided that the number of smoothing steps is sufficiently large. We also show that the symmetric variable -cycle algorithm is an optimal preconditioner.