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1.
We show that for each positive integerk there is ak×k matrixB with ±1 entries such that puttingE to be the span of the rows of thek×2k matrix [√kI
k,B], thenE,E
⊥ is a Kashin splitting: TheL
1
2k
and theL
2
2k
are universally equivalent on bothE andE
⊥. Moreover, the probability that a random ±1 matrix satisfies the above is exponentially close to 1.
Supported by the Israel Science Foundation. 相似文献
2.
In this paper, we investigate a generalization of graph decomposition, called hypergraph decomposition. We show that a decomposition of a 3-uniform hypergraph K(3)v into a special kind of hypergraph K(3)4 - e exists if and only if v ≡ 0, 1, 2 (mod 9) and v ≥ 9. 相似文献
3.
A. M. Shapiro 《Theoretical and Mathematical Physics》2010,165(2):1421-1434
We establish explicit isomorphisms between three realizations of the quantum twisted affine algebra U
q
(A
2
(2): the Drinfeld current realization, the Chevalley realization, and the so-called RLL realization proposed by Reshetikhin, Takhtajan,
and Faddeev. 相似文献
4.
U. Goginava 《Ukrainian Mathematical Journal》2005,57(11):1818-1824
In this paper, a necessary and sufficient condition for the inclusion of the class ΛBV in the class H
p
ω
is found.
Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 57, No. 11, pp. 1557–1562, November, 2005. 相似文献
5.
N. V. Parfinovych 《Ukrainian Mathematical Journal》2005,57(10):1652-1662
We determine the exact order of relative widths of classes W
1
r
of periodic functions in the space L
1 as n → ∞ under restrictions on higher derivatives of approximating functions.
__________
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 57, No. 10, pp. 1409–1417, October, 2005. 相似文献
6.
A. I. Khrabrov 《Journal of Mathematical Sciences》2005,129(4):4040-4048
We study classical, modified, and weak Banach-Mazur distances between sums of the spaces ℓ
n
p
. We calculate explicitly the classical and weak Banach-Mazur distances between sums of the spaces ℓ
n
p
and obtain bounds for ratios of distances between sums of the spaces ℓ
n
p
. Bibliography: 14 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 303, 2003, pp. 203–217. 相似文献
7.
ZhangJianfeng 《高校应用数学学报(英文版)》2005,20(2):183-196
Let M^n be a closed spacelike submanifold isometrically immersed in de Sitter space Sp^(n p)(c), Denote by R,H and S the normalized scalar curvature,the mean curvature and the square of the length of the second fundamental form of M^n ,respectively. Suppose R is constant and R≤c. The pinching problem on S is studied and a rigidity theorem for M^n immersed in Sp^(n p)(c) with parallel normalized mean curvature vector field is proved. When n≥3, the pinching constant is the best. Thus, the mistake of the paper “Space-like hypersurfaces in de Sitter space with constant scalar curvature”(see Manus Math, 1998,95 :499-505) is corrected. Moreover,the reduction of the codimension when M^n is a complete submanifold in Sp^(n p)(c) with parallel normalized mean curvature vector field is investigated. 相似文献
8.
9.
It is proved that finite simple groups L4(2m), m ⩾ 2, and U4(2m), m ⩾ 2, are, up to isomorphism, recognized by spectra, i.e., sets of their element orders, in the class of finite groups.
As a consequence the question on recognizability by spectrum is settled for all finite simple groups without elements of order
8.
Supported by RFBR (grant Nos. 05-01-00797 and 06-01-39001), by SB RAS (Complex Integration project No. 1.2), and by the Ministry
of Education of China (Project for Retaining Foreign Expert).
Supported by NSF of Chongqing (CSTC: 2005BB8096).
__________
Translated from Algebra i Logika, Vol. 47, No. 1, pp. 83–93, January–February, 2008. 相似文献
10.
Countably generated prime ideals in <Emphasis Type="Italic">H</Emphasis><Superscript>∞</Superscript>
We confirm a twenty year old conjecture by showing that a nonzero prime ideal P in the algebra H∞ of bounded analytic functions in the open unit disk is countably generated if and only if it is either a principal ideal
generated by the polynomial z−z0, |z0|<1, or if P is generated by the n-th roots of an atomic inner function. The case of the algebra H∞+C is also dealt with.
Dedicated to the 70th birthday of Joseph Cima
Research supported by the RIP-program Oberwolfach 2004. 相似文献
11.
As the main result, we show that if G is a finite group such that Γ(G) = Γ(2
F
4(q)), where q = 22m+1 for some m ≧ 1, then G has a unique nonabelian composition factor isomorphic to 2
F
4(q). We also show that if G is a finite group satisfying |G| =|2
F
4(q)| and Γ(G) = Γ(2
F
4(q)), then G ≅ 2
F
4(q). As a consequence of our result we give a new proof for a conjecture of W. Shi and J. Bi for 2
F
4(q).
The third author was supported in part by a grant from IPM (No. 87200022). 相似文献
12.
V. A. Solonnikov 《Journal of Mathematical Sciences》2008,150(1):1890-1916
We prove sharp estimates in the norms of the Sobolev-Slobodetskii space W
2
l
, l > 0, for volume and surface potentials in domains with boundary of Sobolev class. The estimates are used in the study
of some problems in hydrodynamics for self-gravitating fluids. Bibliography: 4 titles.
__________
Translated from Problemy Matematicheskogo Analiza, No. 36, 2007, pp. 93–111. 相似文献
13.
Romain Dujardin 《Mathematische Annalen》2003,325(4):745-765
In this paper we study laminar currents in ℙ2. Given a sequence of irreducible algebraic curves (C
n
) converging in the sense of currents to T, we find geometric conditions on the curves ensuring that the limit current T is laminar. This criterion is then applied to meromorphic dynamical systems in ℙ2, and laminarity of the dynamical ``Green' current is obtained for a wide class of meromorphic self maps of ℙ2, as well as for all bimeromorphic maps of projective surfaces.
Received: 24 September 2001 / Published online: 10 February 2003
Mathematics Subject Classification (2000): 32U40, 37Fxx, 32H50 相似文献
14.
For any module V over the two-dimensional non-abelian Lie algebra b and scalar α ∈ C, we define a class of weight modules F α (V) with zero central charge over the affine Lie algebra A 1 (1) . These weight modules have infinitedimensional weight spaces if and only if V is infinite dimensional. In this paper, we will determine necessary and sufficient conditions for these modules F α(V) to be irreducible. In this way, we obtain a lot of irreducible weight A 1 (1) -modules with infinite-dimensional weight spaces. 相似文献
15.
A. G. Bakan 《Ukrainian Mathematical Journal》2005,57(3):364-381
In the criterion for polynomial denseness in the space C
w
0
established by de Branges in 1959, we replace the requirement of the existence of an entire function by an equivalent requirement
of the existence of a polynomial sequence. We introduce the notion of strict compactness of polynomial sets and establish
sufficient conditions for a polynomial family to possess this property.
__________
Translated from Ukrains'kyi Matematychnyi Zhurnal, Vol. 57, No. 3, pp. 305–319, March, 2005. 相似文献
16.
Yun Qing Xu 《数学学报(英文版)》2009,25(8):1325-1336
A Latin squares of order v with ni missing sub-Latin squares (holes) of order hi (1 〈= i 〈 k), which are disjoint and spanning (i.e. ∑k i=l1 nihi = v), is called a partitioned incomplete Latin squares and denoted by PILS. The type of PILS is defined by (h1n1 h2n2…hknk ). If any two PILS inaset of t PILS of type T are orthogonal, then we denote the set by t-HMOLS(T). It has been proved that 3-HMOLS(2n31) exist for n ≥6 with 11 possible exceptions. In this paper, we investigate the existence of 3-HMOLS(2nu1) with u ≥ 4, and prove that 3-HMOLS(2~u1) exist if n ≥ 54 and n ≥7/4u + 7. 相似文献
17.
Y. Chiang 《Journal of Optimization Theory and Applications》2005,124(3):581-594
In this paper, we extend the (S)
+
1
condition to multivalued mappings in an ordered Hausdorff topological vector space and we derive some existence results for generalized vector variational inequalities associated with multivalued mappings satisfying the (S)
+
1
condition. We generalize also an existence result of Cubiotti and Yao for generalized variational inequalities of class (S)
+
1
to barreled normed spaces. As consequences, some existence results for vector variational inequalities are established.This work was partially supported by grants from the National Science Council of the Republic of China.
Communicated by H. P. Benson 相似文献
18.
19.
Let M{\mathcal M} be a σ-finite von Neumann algebra and
\mathfrak A{\mathfrak A} a maximal subdiagonal algebra of M{\mathcal M} with respect to a faithful normal conditional expectation F{\Phi} . Based on Haagerup’s noncommutative L
p
space Lp(M){L^p(\mathcal M)} associated with M{\mathcal M} , we give a noncommutative version of H
p
space relative to
\mathfrak A{\mathfrak A} . If h
0 is the image of a faithful normal state j{\varphi} in L1(M){L^1(\mathcal M)} such that j°F = j{\varphi\circ \Phi=\varphi} , then it is shown that the closure of
{\mathfrak Ah0\frac1p}{\{\mathfrak Ah_0^{\frac1p}\}} in Lp(M){L^p(\mathcal M)} for 1 ≤ p < ∞ is independent of the choice of the state preserving F{\Phi} . Moreover, several characterizations for a subalgebra of the von Neumann algebra M{\mathcal M} to be a maximal subdiagonal algebra are given. 相似文献
20.
Jeffrey D. Streets 《Journal of Geometric Analysis》2008,18(1):249-271
We study the gradient flow of the Riemannian functional ℱ(g):=∫
M
|Rm|2. This flow corresponds to a fourth-order degenerate parabolic equation for a Riemannian metric. We prove that the degeneracies
may be accounted for entirely by diffeomorphism flow, and hence we show short-time existence using the DeTurck method. We
prove L
2 derivative estimates of Bernstein-Bando-Shi type and use these to give a basic obstruction to long time existence and prove
a compactness theorem.
相似文献