共查询到20条相似文献,搜索用时 31 毫秒
1.
Diarmuid Crowley 《Geometriae Dedicata》2010,148(1):15-33
We calculate \({\mathcal{S}^{{\it Diff}}(S^p \times S^q)}\), the smooth structure set of S p × S q , for p, q ≥ 2 and p + q ≥ 5. As a consequence we show that in general \({\mathcal{S}^{Diff}(S^{4j-1}\times S^{4k})}\) cannot admit a group structure such that the smooth surgery exact sequence is a long exact sequence of groups. We also show that the image of the forgetful map \({\mathcal{S}^{Diff}(S^{4j}\times S^{4k}) \rightarrow \mathcal{S}^{Top}(S^{4j}\times S^{4k})}\) is not in general a subgroup of the topological structure set. 相似文献
2.
Crossing numbers of graphs are in general very difficult to compute. There are several known exact results on the crossing
number of the Cartesian products of paths, cycles or stars with small graphs. In this paper we study cr(Km □ Pn), the crossing number of the Cartesian product Km □ Pn. We prove that
for m ≥ 3,n ≥ 1 and cr(Km □ Pn)≥ (n − 1)cr(Km+2 − e) + 2cr(Km+1). For m≤ 5, according to Klešč, Jendrol and Ščerbová, the equality holds. In this paper, we also prove that the equality holds for
m = 6, i.e., cr(K6 □ Pn) = 15n + 3.
Research supported by NFSC (60373096, 60573022). 相似文献
3.
The minimum number of total independent partition sets of V ∪ E of graph G(V,E) is called the total chromatic number of G denoted by χ
t
(G). If the difference of the numbers of any two total independent partition sets of V ∪ E is no more than one, then the minimum number of total independent partition sets of V ∪ E is called the equitable total chromatic number of G, denoted by χ
et
(G). In this paper, we obtain the equitable total chromatic number of the join graph of fan and wheel with the same order.
Supported by the National Natural Science Foundation of China (No. 10771091). 相似文献
4.
In this paper, the structure of the critical group of the graph K
m
× C
n
is determined, where m, n ≥ 3. 相似文献
5.
Tao Feng 《Designs, Codes and Cryptography》2009,51(2):175-194
Let D be a (v, k, λ)-difference set in an abelian group G, and (v, 31) = 1. If n = 5p
r
with p a prime not dividing v and r a positive integer, then p is a multiplier of D. In the case 31|v, we get restrictions on the parameters of such difference sets D for which p may not be a multiplier.
相似文献
6.
In this paper, we show that, for each p 〉 1, there are continuum many Borel equivalence relations between Rω/l1 and Rω/p ordered by ≤B which are pairwise Borel incomparable. 相似文献
7.
Topological free involutions on S
1 × S
n
are classified up to conjugation. We prove that this is the same as classifying quotient manifolds up to homeomorphism. There
are exactly four possible homotopy types of such quotients, and surgery theory is used to classify all manifolds within each
homotopy type. 相似文献
8.
There is a natural duality between orbits of a real form G of a complex semisimple group G
on a homogeneous rational manifold Z=G
/P and those of the complexification K
of any of its maximal compact subgroups K: (,) is a dual pair if is a K-orbit. The cycle space C() is defined to be the connected component containing the identity of the interior of {g:g() is non-empty and compact}. Using methods which were recently developed for the case of open G-orbits, geometric properties of cycles are proved, and it is shown that C() is contained in a domain defined by incidence geometry. In the non-Hermitian case this is a key ingredient for proving that C() is a certain explicitly computable universal domain.Research of the first author partially supported by Schwerpunkt Global methods in complex geometry and SFB-237 of the Deutsche Forschungsgemeinschaft.The second author was supported by a stipend of the Deutsche Akademische Austauschdienst. 相似文献
9.
In this paper theI andII regularn-simplices are introduced. We prove that the sufficient and necessary conditions for existence of anI regularn-simplex in ℝ
n
are that ifn is even thenn = 4m(m + 1), and ifn is odd thenn = 4m + 1 with thatn + 1 can be expressed as a sum of two integral squares orn = 4m - 1, and that the sufficient and necessary condition for existence of aII regularn-simplex in ℝ
n
isn = 2m
2 - 1 orn = 4m(m + 1)(m ∈ ℕ). The connection between regularn-simplex in ℝ
n
and combinational design is given. 相似文献
10.
This paper is concerned with the study of the set P
-1(0), when P varies over all orthogonally additive polynomials on
p
and L
p
spaces. We apply our results to obtain characterizations of the weak-polynomial topologies associated to this class of polynomials. 相似文献
11.
We define and construct Ramanujan complexes. These are simplicial complexes which are higher dimensional analogues of Ramanujan graphs (constructed in [LPS]). They are obtained as quotients of the buildings of typeà d?1 associated with PGL d (F) whereF is a local field of positive characteristic. 相似文献
12.
Iwo Labuda 《Positivity》2010,14(4):801-813
Let μ be a measure from a σ-algebra of subsets of a set T into a sequentially complete Hausdorff topological vector space X. Assume that μ is convexly bounded, i.e., the convex hull of its range is bounded in X, and denote by L
1(μ) the space of scalar valued functions on T which are integrable with respect to the vector measure μ. We study the inheritance of some properties from X to L
1(μ). We show that the bounded multiplier property passes from X to L
1(μ). Answering a 1972 problem of Erik Thomas, we show that for a rather large class of F-spaces X the non-containment of c
0 passes from X to L
1(μ). 相似文献
13.
Emília Draženská 《Mathematica Slovaca》2011,61(5):675-686
The crossing numbers of Cartesian products of paths, cycles or stars with all graphs of order at most four are known. The
crossing numbers of G□C
n
for some graphs G on five and six vertices and the cycle C
n
are also given. In this paper, we extend these results by determining the crossing number of the Cartesian product G □ C
n
, where G is a specific graph on six vertices. 相似文献
14.
Guy David 《Journal of Geometric Analysis》2010,20(4):837-954
We give a new proof and a partial generalization of Jean Taylor’s result (Ann. Math. (2) 103(3), 489–539, 1976) that says that Almgren almost-minimal sets of dimension 2 in ℝ3 are locally C
1+α
-equivalent to minimal cones. The proof is rather elementary, but uses a local separation result proved in Ann. Fac. Sci.
Toulouse 18(1), 65–246, 2009 and an extension of Reifenberg’s parameterization theorem (David et al. in Geom. Funct. Anal. 18, 1168–1235, 2008). The key idea is still that if X is the cone over an arc of small Lipschitz graph in the unit sphere, but X is not contained in a disk, we can use the graph of a harmonic function to deform X and substantially diminish its area. The local separation result is used to reduce to unions of cones over arcs of Lipschitz
graphs. A good part of the proof extends to minimal sets of dimension 2 in ℝ
n
, but in this setting our final regularity result on E may depend on the list of minimal cones obtained as blow-up limits of E at a point. 相似文献
15.
Free completely <Emphasis Type="Italic">J</Emphasis><Superscript>(<Emphasis Type="Italic">ℓ</Emphasis>)</Superscript>-simple Semigroups 下载免费PDF全文
A semigroup is called completely J(ι)-simple if it is isomorphic to some Rees matrix semigroup over a left cancellative monoid and each entry of whose sandwich matrix is in the group of units of the left cancellative monoid. It is proved that completely J(ι)-simple semigroups form a quasivarity. Moreover, the construction of free completely J(ι)-simple semigroups is given. It is found that a free completely J(ι)-simple semigroup is just a free completely J *-simple semigroup and also a full subsemigroup of some completely simple semigroups. 相似文献
16.
Yu. K. Dem’yanovich 《Journal of Mathematical Sciences》2009,156(4):577-588
A general approach to the construction of asymptotics of coordinate (not necessarily polynomial) B
φ
-splines of an arbitrary order is proposed. Asymptotic representations for Lagrange type third order B
φ
-splines are obtained. Bibliography: 4 titles.
Translated from Problemy Matematicheskogo Analiza, No. 38, December 2008, pp. 11–21. 相似文献
17.
The set of all non-increasing nonnegative integer sequences π = (d(v
1), d(v
2), …, d(v
n
)) is denoted by NS
n
. A sequence π ∈ NS
n
is said to be graphic if it is the degree sequence of a simple graph G on n vertices, and such a graph G is called a realization of π. The set of all graphic sequences in NS
n
is denoted by GS
n
. A graphical sequence π is potentially H-graphical if there is a realization of π containing H as a subgraph, while π is forcibly H-graphical if every realization of π contains H as a subgraph. Let K
k
denote a complete graph on k vertices. Let K
m
−H be the graph obtained from Km by removing the edges set E(H) of the graph H (H is a subgraph of K
m
). This paper summarizes briefly some recent results on potentially K
m
−G-graphic sequences and give a useful classification for determining σ (H, n). 相似文献
18.
By an extended triangle, we mean a loop, a loop with an edge attached (known as a lollipop), or a copy of K
3 (known as a triangle). In this paper, we completely solve the problem of decomposing the graph (λK
υ
)+ into extended triangles for all possible number of loops.
Dedicated to Professor Alex Rosa on the occasion of his 70th birthday 相似文献
19.
M. A. Podkolzina 《Moscow University Mathematics Bulletin》2009,64(1):39-40
The problem on the number of precomplete classes in the functional system P κ τ is considered, elements of P κ τ are deterministic S-functions defined on words of length τ composed from letters of an alphabet of cardinality κ. An asymptotics for the number of S-precomplete classes in P κ τ is obtained for arbitrary fixed κ and τ tending to infinity. 相似文献
20.
Let X be a (closed) subspace of Lp with 1≤p<∞, and let A be any sectorial operator on X. We consider associated square functions on X, of the form and we show that if A admits a bounded H∞ functional calculus on X, then these square functions are equivalent to the original norm of X. Then we deduce a similar result when X=H1(ℝN) is the usual Hardy space, for an appropriate choice of || ||F. For example if N=1, the right choice is the sum for h ∈ H1(ℝ), where H denotes the Hilbert transform. 相似文献