共查询到20条相似文献,搜索用时 46 毫秒
1.
A.G. Smirnov 《Journal of Mathematical Analysis and Applications》2009,351(1):57-69
In [A.G. Smirnov, Fourier transformation of Sato's hyperfunctions, Adv. Math. 196 (2005) 310-345] the author introduced a new generalized function space U(Rk) which can be naturally interpreted as the Fourier transform of the space of Sato's hyperfunctions on Rk. It was shown that all Gelfand-Shilov spaces (α>1) of analytic functionals are canonically embedded in U(Rk). While the usual definition of support of a generalized function is inapplicable to elements of and U(Rk), their localization properties can be consistently described using the concept of carrier cone introduced by Soloviev [M.A. Soloviev, Towards a generalized distribution formalism for gauge quantum fields, Lett. Math. Phys. 33 (1995) 49-59; M.A. Soloviev, An extension of distribution theory and of the Paley-Wiener-Schwartz theorem related to quantum gauge theory, Comm. Math. Phys. 184 (1997) 579-596]. In this paper, the relation between carrier cones of elements of and U(Rk) is studied. It is proved that an analytic functional is carried by a cone K⊂Rk if and only if its canonical image in U(Rk) is carried by K. 相似文献
2.
We study isomorphic properties of two generalizations of intersection bodies - the class of k-intersection bodies in Rn and the class of generalized k-intersection bodies in Rn. In particular, we show that all convex bodies can be in a certain sense approximated by intersection bodies, namely, if K is any symmetric convex body in Rn and 1≤k≤n−1 then the outer volume ratio distance from K to the class can be estimated by
3.
Luke G. Rogers 《Journal of Functional Analysis》2006,235(2):619-665
We consider the problem of constructing extensions , where is the Sobolev space of functions with k derivatives in Lp and Ω⊂Rn is a domain. In the case of Lipschitz Ω, Calderón gave a family of extension operators depending on k, while Stein later produced a single (k-independent) operator. For the more general class of locally-uniform domains, which includes examples with highly non-rectifiable boundaries, a k-dependent family of operators was constructed by Jones. In this work we produce a k-independent operator for all spaces on a locally uniform domain Ω. 相似文献
4.
L. Sunil Chandran 《Discrete Mathematics》2008,308(23):5795-5800
For a graph G, its cubicity is the minimum dimension k such that G is representable as the intersection graph of (axis-parallel) cubes in k-dimensional space. (A k-dimensional cube is a Cartesian product R1×R2×?×Rk, where Ri is a closed interval of the form [ai,ai+1] on the real line.) Chandran et al. [L.S. Chandran, C. Mannino, G. Oriolo, On the cubicity of certain graphs, Information Processing Letters 94 (2005) 113-118] showed that for a d-dimensional hypercube Hd, . In this paper, we use the probabilistic method to show that . The parameter boxicity generalizes cubicity: the boxicity of a graph G is defined as the minimum dimension k such that G is representable as the intersection graph of axis-parallel boxes in k-dimensional space. Since for any graph G, our result implies that . The problem of determining a non-trivial lower bound for is left open. 相似文献
5.
A k-dimensional box is the Cartesian product R1×R2×?×Rk where each Ri is a closed interval on the real line. The boxicity of a graph G, denoted as is the minimum integer k such that G is the intersection graph of a collection of k-dimensional boxes. Halin graphs are the graphs formed by taking a tree with no degree 2 vertex and then connecting its leaves to form a cycle in such a way that the graph has a planar embedding. We prove that if G is a Halin graph that is not isomorphic to K4, then . In fact, we prove the stronger result that if G is a planar graph formed by connecting the leaves of any tree in a simple cycle, then unless G is isomorphic to K4 (in which case its boxicity is 1). 相似文献
6.
A k-dimensional box is the cartesian product R1×R2×?×Rk where each Ri is a closed interval on the real line. The boxicity of a graph G, denoted as box(G), is the minimum integer k such that G is the intersection graph of a collection of k-dimensional boxes. A unit cube in k-dimensional space or a k-cube is defined as the cartesian product R1×R2×?×Rk where each Ri is a closed interval on the real line of the form [ai,ai+1]. The cubicity of G, denoted as cub(G), is the minimum k such that G is the intersection graph of a collection of k-cubes. In this paper we show that cub(G)≤t+⌈log(n−t)⌉−1 and , where t is the cardinality of a minimum vertex cover of G and n is the number of vertices of G. We also show the tightness of these upper bounds.F.S. Roberts in his pioneering paper on boxicity and cubicity had shown that for a graph G, and , where n is the number of vertices of G, and these bounds are tight. We show that if G is a bipartite graph then and this bound is tight. We also show that if G is a bipartite graph then . We point out that there exist graphs of very high boxicity but with very low chromatic number. For example there exist bipartite (i.e., 2 colorable) graphs with boxicity equal to . Interestingly, if boxicity is very close to , then chromatic number also has to be very high. In particular, we show that if , s≥0, then , where χ(G) is the chromatic number of G. 相似文献
7.
In this article we classify all positive finite energy solutions of the equation in Rn where and a point x∈Rn is denoted as x=(y,z)∈Rk×Rn-k. As a consequence we obtain the best constant and extremals of a related Hardy-Sobolev inequality. 相似文献
8.
F. Couchot 《Journal of Pure and Applied Algebra》2006,207(1):63-76
If is the pure-injective hull of a valuation ring R, it is proved that is the pure-injective hull of M, for every finitely generated R-module M. Moreover , where (Ak)1≤k≤n is the annihilator sequence of M. The pure-injective hulls of uniserial or polyserial modules are also investigated. Any two pure-composition series of a countably generated polyserial module are isomorphic. 相似文献
9.
Douglas S. Stones 《Journal of Combinatorial Theory, Series A》2010,117(2):204-215
A k×n Latin rectangle on the symbols {1,2,…,n} is called reduced if the first row is (1,2,…,n) and the first column is T(1,2,…,k). Let Rk,n be the number of reduced k×n Latin rectangles and m=⌊n/2⌋. We prove several results giving divisors of Rk,n. For example, (k−1)! divides Rk,n when k?m and m! divides Rk,n when m<k?n. We establish a recurrence which determines the congruence class of for a range of different t. We use this to show that Rk,n≡((−1)k−1(k−1)!)n−1. In particular, this means that if n is prime, then Rk,n≡1 for 1?k?n and if n is composite then if and only if k is larger than the greatest prime divisor of n. 相似文献
10.
For a commutative noetherian ring R with residue field k stable cohomology modules have been defined for each n∈Z, but their meaning has remained elusive. It is proved that the k-rank of any characterizes important properties of R, such as being regular, complete intersection, or Gorenstein. These numerical characterizations are based on results concerning the structure of Z-graded k-algebra carried by stable cohomology. It is shown that in many cases it is determined by absolute cohomology through a canonical homomorphism of algebras . Some techniques developed in the paper are applicable to the study of stable cohomology functors over general associative rings. 相似文献
11.
M. Bhakta 《Journal of Differential Equations》2009,247(1):119-139
We study the regularity, Palais-Smale characterization and existence/nonexistence of solutions of the Hardy-Sobolev-Maz'ya equation in a bounded domain in RN where x∈RN is denoted as x=(y,z)∈Rk×RN−k and . We show different behaviors of PS sequences depending on t=0 or t>0. 相似文献
12.
Lech Bart?omiejczyk Janusz Morawiec 《Journal of Mathematical Analysis and Applications》2006,319(1):295-301
For all integers m,k>1 with m≡1modk we construct, among others, a function with dense graph in the set [0,k]×R such that
13.
Manuel del Pino Frank Pacard Angela Pistoia 《Journal of Differential Equations》2011,251(9):2568-2597
We consider the Yamabe equation in Rn, n?3. Let k?1 and . For all large k we find a solution of the form , where , for n?4, for n=3 and o(1)→0 uniformly as k→+∞. 相似文献
14.
Joaquín Motos María Jesús Planells César F. Talavera 《Journal of Mathematical Analysis and Applications》2008,338(1):162-174
It is proved that the Hörmander and spaces (Ω1⊂Rn, Ω2⊂Rm open sets, 1?p<∞, ki Beurling-Björck weights, k=k1⊗k2) are isomorphic whereas the iterated spaces and are not if 1<p≠q<∞. A similar result for weighted Lp-spaces of entire analytic functions is also obtained. Finally a result on iterated Besov spaces is given: and are not isomorphic when 1<q≠2<∞. 相似文献
15.
Reza Sazeedeh 《Journal of Pure and Applied Algebra》2008,212(1):275-280
Let R=?n∈N0Rn be a Noetherian homogeneous ring with local base ring (R0,m0) and irrelevant ideal R+, let M be a finitely generated graded R-module. In this paper we show that is Artinian and is Artinian for each i in the case where R+ is principal. Moreover, for the case where , we prove that, for each i∈N0, is Artinian if and only if is Artinian. We also prove that is Artinian, where and c is the cohomological dimension of M with respect to R+. Finally we present some examples which show that and need not be Artinian. 相似文献
16.
Zhongxiang Zhang 《Journal of Mathematical Analysis and Applications》2006,315(2):491-505
In this paper, we mainly study properties of nullsolutions of the operator Dk (k∈N∗=N?{0}), so-called k-regular functions. Firstly, we study the set of all homogeneous polynomials of degree p in x1,…,xn which are k-regular in the whole Rn, clearly is a right module over C(Vn,n), we construct a basis for the right module . Secondly, we study the k-regular and analytic functions, and we give the Taylor expansions for these functions. At last, the corresponding Taylor expansions for k-regular functions are given since each k-regular function is a real analytic function. 相似文献
17.
Karim Samei 《Journal of Pure and Applied Algebra》2007,209(3):813-821
In this paper the zero-divisor graph Γ(R) of a commutative reduced ring R is studied. We associate the ring properties of R, the graph properties of Γ(R) and the topological properties of . Cycles in Γ(R) are investigated and an algebraic and a topological characterization is given for the graph Γ(R) to be triangulated or hypertriangulated. We show that the clique number of Γ(R), the cellularity of and the Goldie dimension of R coincide. We prove that when R has the annihilator condition and ; Γ(R) is complemented if and only if is compact. In a semiprimitive Gelfand ring, it turns out that the dominating number of Γ(R) is between the density and the weight of . We show that Γ(R) is not triangulated and the set of centers of Γ(R) is a dominating set if and only if the set of isolated points of is dense in . 相似文献
18.
19.
Takeshi Kurosawa 《Journal of Number Theory》2007,123(1):35-58
Duverney and Nishioka [D. Duverney, Ku. Nishioka, An inductive method for proving the transcendence of certain series, Acta Arith. 110 (4) (2003) 305-330] studied the transcendence of , where Ek(z), Fk(z) are polynomials, α is an algebraic number, and r is an integer greater than 1, using an inductive method. We extend their inductive method to the case of several variables. This enables us to prove the transcendence of , where Rn is a binary linear recurrence and {ak} is a sequence of algebraic numbers. 相似文献
20.
Let k be a positive integer and G be a connected graph. This paper considers the relations among four graph theoretical parameters: the k-domination number γk(G), the connected k-domination number ; the k-independent domination number and the k-irredundance number irk(G). The authors prove that if an irk-set X is a k-independent set of G, then , and that for k?2, if irk(G)=1, if irk(G) is odd, and if irk(G) is even, which generalize some known results. 相似文献