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1.
This article classifies all {(q + 1), 3, q}-minihypers, small, q = p
h
0, h 1, for a prime number p
0 7, which arise from a maximal partial spread of deficiency . When q is a third power, the minihyper is the disjoint union of projected PG(5,
)'s; when q is a square, also Baer subgeometries PG(3,
) can occur. This leads to a discrete spectrum for the small values of the deficiency of the corresponding maximal partial spreads. 相似文献
2.
Martin Bokler 《Designs, Codes and Cryptography》2001,24(2):131-144
In this paper minimal m-blocking sets of cardinality at most
in projective spaces PG(n,q) of square order q, q 16, are characterized to be (t, 2(m-t-1))-cones for some t with
. In particular we will find the smallest m-blocking sets that generate the whole space PG(n,q) for 2m n m. 相似文献
3.
All finite fields
q (q 2, 3, 4, 5, 7, 9, 13, 25, 121) contain a primitive element for which + 1/ is also primitive. All fields of square order
q
2 (q 3, 5) contain an element of order q + 1 for which + 1/ is a primitive element of the subfield
q. These are unconditional versions of general asymptotic results. 相似文献
4.
Denote by a flock of a quadratic cone of PG(3,q) by S() the spread of PG(3,q) associated with and by l the common line of the base reguli. Suppose that there are two lines not transversal to a base regulus which share the same lines of S() Then we prove that is either linear or a Kantor-Knuth semifield flock. Using this property we can extend the result of J3 on derivable flocks proving that, if a set of q + 1 lines of S() defines a derivable net different from a base regulus-net, then is either linear or a Kantor-Knuth semifield flock. Moreover if l is not a component of the derivable net, then is linear. 相似文献
5.
Atube of even orderq=2
d
is a setT={L,
} ofq+3 pairwise skew lines in PG(3,q) such that every plane onL meets the lines of
in a hyperoval. Thequadric tube is obtained as follows. Take a hyperbolic quadricQ=Q
3
+
(q) in PG(3,q); letL be an exterior line, and let
consist of the polar line ofL together with a regulus onQ.In this paper we show the existence of tubes of even order other than the quadric one, and we prove that the subgroup of PL(4,q) fixing a tube {L,
} cannot act transitively on
. As pointed out by a construction due to Pasini, this implies new results for the existence of flat .C
2 geometries whoseC
2-residues are nonclassical generalized quadrangles different from nets. We also give the results of some computations on the existence and uniqueness of tubes in PG(3,q) for smallq. Further, we define tubes for oddq (replacing hyperoval by conic in the definition), and consider briefly a related extremal problem.Dedicated to luigi antonio rosati on the occasion of his 70th birthday 相似文献
6.
Let be a set of
exterior points of a nondegenerate conic inPG(2,q) with the property that the line joining any 2 points in misses the conic. Ifq1 (mod 4) then consists of the exterior points on a passant, ifq3 (mod 4) then other examples exist (at least forq=7, 11, ..., 31).Support from the Dutch organization for scientific Research (NWO) is gratefully acknowledged 相似文献
7.
Abdelhafed Elkhadiri 《Bulletin of the Brazilian Mathematical Society》2000,31(1):45-71
Let be an open subset of
n
and
be a subalgebra of the algebra of analytic functions on . We suppose that
satisfies some weak conditions of noetherianity such that we can construct a finite stratification for each ideal of
. We also suppose that
satifies global £ojasiewicz's inequalities. We prove the following: Let
andf C
on
flat on ; if for eacha the Taylor's serie off ata, T
a
f, is in the ideal generated byT
a
f
1,...,T
a
f
p
in the ring of formal power series, then there exist
1,...,
p
,C
on
flat on such that
. This result extends the classic Hormander's theorem of division (for a polynomial) or the £ojasiewicz-Malgrange theorem in the local analytic case.Reherches menées dans le cadre du Programme d'Appui à la Recherche Scientifique (PARS MI 33) 相似文献
8.
R. A. Danao 《Journal of Optimization Theory and Applications》1997,95(2):445-454
Consider the parametric linear complementarity problem w=Mz+q+p, w0, z0, w
T
z=0, where p0, 0q0, and 0. We show that a necessary condition for every complementary map z() to be isotone for every nonzero q0 and every p is that M be either a P-matrix or a
-matrix. The Cottle necessary and sufficient conditions for strong and uniform isotonicity for P-matrices are restated, with slight modifications, for
-matrices. 相似文献
9.
A t-cover of a quadric
is a set C of t-dimensional subspaces contained in
such that every point of
is contained in at least one element of C.We consider (n – 1)-covers of the hyperbolic quadric Q
+(2n + 1, q). We show that such a cover must have at least q
n + 1 + 2q + 1 elements, give an example of this size for even q and describe what covers of this size should look like. 相似文献
10.
Laurent Denis 《Monatshefte für Mathematik》1997,123(1):43-51
Lete and be the Carlitz-module analogues of their usual counterparts. We have proved in [4]-that these elements of
are algebraically independent over
whenq3. We study here the remaining caseq=2 and prove among other things that 1,e, are linearly independent over
. 相似文献
11.
Liming Yang 《Integral Equations and Operator Theory》1996,25(3):373-376
Let 1<p< and
. LetC
q
denote the Bessel capacity in the plane. Let
be the set of homomorphisms ofH
(G) such that (z)= and letNP denote the set of points in G for which
is not a peak set forH
(G). In this note, we show that ifC
q
(NP)=0, thenH
(G) is dense inL
a
p
(G), the Bergman space overG.Partially supported by NSF DMS-9401234 相似文献
12.
Noboru Hamada 《Designs, Codes and Cryptography》1997,10(1):41-56
Let k and d be any integers such that k 4 and
. Then there exist two integers and in {0,1,2} such that
. The purpose of this paper is to prove that (1) in the case k 5 and (,) = (0,1), there exists a ternary
code meeting the Griesmer bound if and only if
and (2) in the case k 4 and (,) = (0,2) or (1,1), there is no ternary
code meeting the Griesmer bound for any integers k and d and (3) in the case k 5 and
, there is no projective ternary
code for any integers k and such that 1k-3, where
and
for any integer i 0. In the special case k=6, it follows from (1) that there is no ternary linear code with parameters [233,6,154] , [234,6,155] or [237,6,157] which are new results. 相似文献
13.
In this article we study minimal1-blocking sets in finite projective spaces PG(n,q),n 3. We prove that in PG(n,q
2),q = p
h
, p prime, p > 3,h 1, the second smallest minimal 1-blockingsets are the second smallest minimal blocking sets, w.r.t.lines, in a plane of PG(n,q
2). We also study minimal1-blocking sets in PG(n,q
3), n 3, q = p
h, p prime, p > 3,q 5, and prove that the minimal 1-blockingsets of cardinality at most q
3 + q
2 + q + 1 are eithera minimal blocking set in a plane or a subgeometry PG(3,q). 相似文献
14.
We obtain exact order estimates for the trigonometric widths of the classes
of periodic functions of many variables in the space L
q, 1 < p 2 q < p/(p – 1). 相似文献
15.
Summary Suppose thatf:
n
, 0
p
, 0 is finitely
-determined withnp. We define a Milnor fiber for the discriminant off; it is the discriminant of a stabilization off. We prove that this discriminant Milnor fiber has the homotopy type of a wedge of spheres of dimensionp–1, whose number we denote byµ
(f). One of the main theorems of the paper is a = type result: if (n, p) is in the range of nice dimensions in the sense of Mather, then
-codium,with equality iff is weighted homogeneous. Outside the nice dimensions we obtain analogous formulae with correction terms measuring the presence of unstable but topologically stable germs in the stabilization. These results are further extended to nonlinear sections of free divisors.Oblatum 15-VIII-1990Partially supported by a grant from the National Science Foundation and a Fullbright Fellowship 相似文献
16.
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
17.
Let p be a prime, G
a finite group which has a normal p-subgroup
containing its own centralizer in G, and
R a commutative local ring with residue class
field of characteristic p. In this paper, it is
shown that if
is an augmented automorphism of
RG which fixes a Sylow
p-subgroup P
of G, there is
such that
for all
and
is an inner automorphism of
RG.
Received: 26 July 2000 相似文献
18.
The flag geometry =(
) of a finite projective plane of order s is the generalized hexagon of order (s, 1) obtained from by putting
equal to the set of all flags of , by putting
equal to the set of all points and lines of and where I is the natural incidence relation (inverse containment), i.e., is the dual of the double of in the sense of Van Maldeghem Mal:98. Then we say that is fully and weakly embedded in the finite projective space PG(d, q) if is a subgeometry of the natural point-line geometry associated with PG(d, q), if s = q, if the set of points of generates PG(d, q), and if the set of points of not opposite any given point of does not generate PG(d, q). Preparing the classification of all such embeddings, we construct in this paper the classical examples, prove some generalities and show that the dimension d of the projective space belongs to {6,7,8}. 相似文献
19.
Tatsuya Maruta 《Designs, Codes and Cryptography》2001,22(2):165-177
There do not exist
codes over the Galois field GF
attaining the Griesmer bound for
for
andfor
for
. 相似文献
20.
We characterize the Sobolev spaces W1,p(n) (p]1,+]), the space BV(n) of functions of bounded variation, the Nikol'skij spacesN
p
(R
n
=B
p
(R
n
) (p [1, + [, ]0,1[).This research was partially supported by M.U.R.S.T. 相似文献