共查询到20条相似文献,搜索用时 46 毫秒
1.
The Cesàro operator is shown to be subdecomposable on the Bergman spaces Ap (\mathbbD) A^{p} (\mathbb{D}) for p \geqq 2 p \geqq 2 , extending a result of [12] to the case that p < 4. For A2 (\mathbbD) A^{2} (\mathbb{D}) , we show that Cesàro operator is in fact subscalar, but in contrast to the situation in the Hardy space, C |A2 C |_{A^2} fails to be hyponormal. 相似文献
2.
Igor V. Protasov 《Algebra Universalis》2009,62(4):339-343
Let ${\mathbb{A}}Let
\mathbbA{\mathbb{A}} be a universal algebra of signature Ω, and let I{\mathcal{I}} be an ideal in the Boolean algebra
P\mathbbA{\mathcal{P}_{\mathbb{A}}} of all subsets of
\mathbbA{\mathbb{A}} . We say that I{\mathcal{I}} is an Ω-ideal if I{\mathcal{I}} contains all finite subsets of
\mathbbA{\mathbb{A}} and f(An) ? I{f(A^{n}) \in \mathcal{I}} for every n-ary operation f ? W{f \in \Omega} and every A ? I{A \in \mathcal{I}} . We prove that there are 22à0{2^{2^{\aleph_0}}} Ω-ideals in
P\mathbbA{\mathcal{P}_{\mathbb{A}}} provided that
\mathbbA{\mathbb{A}} is countably infinite and Ω is countable. 相似文献
3.
We characterize when an ideal of the algebra ${A(\mathbb{R}^d)}We characterize when an ideal of the algebra
A(\mathbbRd){A(\mathbb{R}^d)} of real analytic functions on
\mathbbRd{\mathbb{R}^d} which is determined by the germ at
\mathbb Rd{\mathbb {R}^d} of a complex analytic set V is complemented under the assumption that either V is homogeneous or
V?\mathbbRd{V\cap \mathbb{R}^d} is compact. The characterization is given in terms of properties of the real singularities of V. In particular, for an arbitrary complex analytic variety V complementedness of the corresponding ideal in
A(\mathbbRd){A(\mathbb{R}^d)} implies that the real part of V is coherent. We also describe the closed ideals of
A(\mathbbRd){A(\mathbb{R}^d)} as sections of coherent sheaves. 相似文献
4.
O. Yu. Dashkova 《Ukrainian Mathematical Journal》2012,63(9):1379-1389
We study a
\mathbbZG \mathbb{Z}G -module A such that
\mathbbZ \mathbb{Z} is the ring of integer numbers, the group G has an infinite sectional p-rank (or an infinite 0-rank), C
G
(A) = 1, A is not a minimax
\mathbbZ \mathbb{Z} -module, and, for any proper subgroup H of infinite sectional p-rank (or infinite 0-rank, respectively), the quotient module A/C
A
(H) is a minimax
\mathbbZ \mathbb{Z} -module. It is shown that if the group G is locally soluble, then it is soluble. Some properties of soluble groups of this kind are discussed. 相似文献
5.
A. Sklar 《Aequationes Mathematicae》2002,64(3):232-247
Summary. The fact that rational numbers of the forms 2-m3n, m and n integers, are dense in the set
\mathbbR+ \mathbb{R}^+ of non-negative real numbers is crucial in determining well-behaved solutions of a key functional equation. A principal aim of this paper is the presentation of a new proof of the statement that many similar sets of rationals are dense in
\mathbbR+ \mathbb{R}^+ . The reason for giving a new proof of this statement is that the "standard" argument uses all the basic properties of logarithms and exponentials. The new proof does not, which means that our result can be used without circularity not only in the characterization, but in the very definition of logarithms and exponential functions. 相似文献
6.
Let
C( \mathbbRm ) C\left( {{\mathbb{R}^m}} \right) be the space of bounded and continuous functions
x:\mathbbRm ? \mathbbR x:{\mathbb{R}^m} \to \mathbb{R} equipped with the norm
|| x ||C = || x ||C( \mathbbRm ): = sup{ | x(t) |:t ? \mathbbRm } \left\| x \right\|C = {\left\| x \right\|_{C\left( {{\mathbb{R}^m}} \right)}}: = \sup \left\{ {\left| {x(t)} \right|:t \in {\mathbb{R}^m}} \right\} 相似文献
7.
Conchita Martínez-Pérez 《Archiv der Mathematik》2003,80(1):25-36
The subject of this paper is the relationship between the set of chief factors of a finite group G and extensions of an irreducible
\mathbbK \mathbb{K} G-module U (
\mathbbK \mathbb{K} a field). Let H / L be a p-chief factor of G. We prove that, if H / L is complemented in a vertex of U, then there is a short exact sequence of Ext-functors for the module U and any
\mathbbK \mathbb{K} G-module V. In some special cases, we prove the converse, which is false in general. We also consider the intersection of the centralizers of all the extensions of U by an irreducible module and provide new bounds for this group. 相似文献
8.
Gabriela Putinar 《Archiv der Mathematik》2003,80(2):130-138
We compare two concepts from distance geometry of finite sets: quasi-isometry and isometry. We show that for every n 3 5 n\geq5 there exist sets of n points in
\mathbbRn-1 \mathbb{R}^{n-1} that are quasi-isometric and not isometric. By contrast, for finite sets in S1 we show that under some additional hypotheses, quasi-isometric sets are isometric. 相似文献
9.
M. Grangé 《Archiv der Mathematik》2002,79(3):197-207
Let W \Omega be a convex open subset of \mathbbCn \mathbb{C}^n with cal C2 {cal C}^2 -boundary, and let a be a point in W \Omega . We prove that for a holomorphic function belonging to the Hardy class Hq(W) H^{q}(\Omega) , the Leibensons divisors at the point a are also in that class. 相似文献
10.
Let A be an absolute valued algebra with left unit. We prove that if A contains a nonzero central element, then A is finite dimensional and is isomorphic to
\mathbb R, \mathbb C{\mathbb {R}, \mathbb {C}} or new classes of four and eight–dimensional absolute valued algebras with left unit. This is more general than those results
in [2] and [3]. 相似文献
11.
12.
Michael Wemyss 《Mathematische Annalen》2011,350(3):631-659
In this paper we show that for any affine complete rational surface singularity the quiver of the reconstruction algebra can
be determined combinatorially from the dual graph of the minimal resolution. As a consequence the derived category of the
minimal resolution is equivalent to the derived category of an algebra whose quiver is determined by the dual graph. Also,
for any finite subgroup G of
GL(2,\mathbbC){{\rm GL}(2,\mathbb{C})}, it means that the endomorphism ring of the special CM
\mathbbC{\mathbb{C}} [[x, y]]
G
-modules can be used to build the dual graph of the minimal resolution of
\mathbbC2/G{\mathbb{C}^{2}/G}, extending McKay’s observation (McKay, Proc Symp Pure Math, 37:183–186, 1980) for finite subgroups of
SL(2,\mathbbC){{\rm SL}(2,\mathbb{C})} to all finite subgroups of
GL(2,\mathbbC){{\rm GL}(2,\mathbb{C})}. 相似文献
13.
Carlson and Toledo conjectured that if an infinite group Γ is the fundamental group of a compact K?hler manifold, then virtually
H2(G, \mathbb R) 1 0{H^{2}(\Gamma, {\mathbb R}) \ne 0} . We assume that Γ admits an unbounded reductive rigid linear representation. This representation necessarily comes from
a complex variation of Hodge structure (
\mathbbC{\mathbb{C}} -VHS) on the K?hler manifold. We prove the conjecture under some assumption on the
\mathbbC{\mathbb{C}} -VHS. We also study some related geometric/topological properties of period domains associated to such a
\mathbbC{\mathbb{C}} -VHS. 相似文献
14.
Olavi Nevanlinna 《Integral Equations and Operator Theory》2011,70(3):419-427
We discuss upper bounds for the resolvent of an
\mathbbR{\mathbb{R}}-linear operator in
\mathbbCd{\mathbb{C}^d}. 相似文献
15.
A.A. Baranov 《Archiv der Mathematik》1999,72(2):101-106
An algebra is called finitary if it consists of finite-rank transformations of a vector space. We classify finitary simple Lie algebras over an algebraically closed field of zero characteristic. It is shown that any such algebra is isomorphic to one of the following¶ (1) a special transvection algebra
\frak t(V,P)\frak t(V,\mit\Pi );¶ (2) a finitary orthogonal algebra
\frak fso (V,q)\frak {fso} (V,q); ¶ (3) a finitary symplectic algebra
\frak fsp (V,s)\frak {fsp} (V,s).¶Here V is an infinite dimensional K-space; q (respectively, s) is a symmetric (respectively, skew-symmetric) nondegenerate bilinear form on V; and P\Pi is a subspace of the dual V* whose annihilator in V is trivial: 0={v ? V | Pv=0}0=\{{v}\in V\mid \Pi {v}=0\}. 相似文献
16.
In this paper we describe, via the Laplace transformation of analytic functionals, a pre-dual to the function algebra A
−∞(D) (D being either a bounded C
2-smooth convex domain in ${\mathbb{C}^N (N > 1)}${\mathbb{C}^N (N > 1)} , or a bounded convex domain in
\mathbbC{\mathbb{C}}) as a space of entire functions with certain growth. A possibility of representation of functions from the pre-dual space
in a form of Dirichlet series with frequencies from D, is also studied. 相似文献
17.
We give some general results on proper-biharmonic submanifolds of a complex space form and, in particular, of the complex
projective space. These results are mainly concerned with submanifolds with constant mean curvature or parallel mean curvature
vector field. We find the relation between the bitension field of the inclusion of a submanifold [`(M)]{\bar{M}} in
\mathbbCPn{\mathbb{C}P^n} and the bitension field of the inclusion of the corresponding Hopf-tube in
\mathbbS2n+1{\mathbb{S}^{2n+1}}. Using this relation we produce new families of proper-biharmonic submanifolds of
\mathbbCPn{\mathbb{C}P^n}. We study the geometry of biharmonic curves of
\mathbbCPn{\mathbb{C}P^n} and we characterize the proper-biharmonic curves in terms of their curvatures and complex torsions. 相似文献
18.
Raul Quiroga-Barranco A. Sanchez-Nungaray 《Integral Equations and Operator Theory》2011,71(2):225-243
We prove the existence of commutative C*-algebras of Toeplitz operators on every weighted Bergman space over the complex projective space
\mathbbPn\mathbb(C){{\mathbb{P}^n}\mathbb{(C)}}. The symbols that define our algebras are those that depend only on the radial part of the homogeneous coordinates. The algebras
presented have an associated pair of Lagrangian foliations with distinguished geometric properties and are closely related
to the geometry of
\mathbbPn\mathbb(C){{\mathbb{P}^n}\mathbb{(C)}}. 相似文献
19.
Cristina Fernández-Córdoba Jaume Pujol Mercè Villanueva 《Designs, Codes and Cryptography》2010,56(1):43-59
A code C{{\mathcal C}} is
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-additive if the set of coordinates can be partitioned into two subsets X and Y such that the punctured code of C{{\mathcal C}} by deleting the coordinates outside X (respectively, Y) is a binary linear code (respectively, a quaternary linear code). The corresponding binary codes of
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-additive codes under an extended Gray map are called
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear codes. In this paper, the invariants for
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear codes, the rank and dimension of the kernel, are studied. Specifically, given the algebraic parameters of
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear codes, the possible values of these two invariants, giving lower and upper bounds, are established. For each possible
rank r between these bounds, the construction of a
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear code with rank r is given. Equivalently, for each possible dimension of the kernel k, the construction of a
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear code with dimension of the kernel k is given. Finally, the bounds on the rank, once the kernel dimension is fixed, are established and the construction of a
\mathbbZ2\mathbbZ4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear code for each possible pair (r, k) is given. 相似文献
20.
We prove that the moduli space \mathfrakML{\mathfrak{M}_L} of Lüroth quartics in \mathbbP2{\mathbb{P}^2}, i.e. the space of quartics which can be circumscribed around a complete pentagon of lines modulo the action of PGL3 (\mathbbC){\mathrm{PGL}_3 (\mathbb{C})} is rational, as is the related moduli space of Bateman seven-tuples of points in \mathbbP2{\mathbb{P}^2}. 相似文献
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