自反代数的双局部导子

证明了自反Banach空间X中自反代数A到B(x)的导子集合是拓扑代数双自反的.     

Lie Derivations of Reflexive Algebras

A Lie derivation is called standard if it is a sum of a derivation and a linear map with image in the center vanishing on commutators. In this paper we show that Lie derivations of a reflexive algebra on a Banach space are standard if is a nest, or has the non-trivial smallest element, or has the non-trivial greatest element. This work was supported by NNSFC (No. 10771154) and PNSFJ (No. BK2007049).     

Jordan Derivations of Reflexive Algebras

Let ${\mathcal L}Let L{\mathcal L} be a subspace lattice on a Banach space X and suppose that ú{L ? L: L_- < X}=X{\vee\{L\in\mathcal L: L_- < X\}=X} or ${\land\{L_- : L \in \mathcal L, L>(0)\}=(0)}${\land\{L_- : L \in \mathcal L, L>(0)\}=(0)} . Then each Jordan derivation from AlgL{\mathcal L} into B(X) is a derivation. This result can apply to completely distributive subspace lattice algebras, J{\mathcal J} -subspace lattice algebras and reflexive algebras with the non-trivial largest or smallest invariant subspace.     

自反代数上的局部Lie $n$-导子

令$\mathcal{L}$是一个满足$X_{-} \neq X$和$(0)_{+} \neq(0)$的Banach空间$X$上的子空间格.我们证明了从${\rm Alg}\,L$映到$B(X)$中的每个局部Lie $n$-导子是一个Lie $n$-导子.     

Lie and Jordan Ideals in Reflexive Algebras

A CDCSL algebra is a reflexive operator algebra with completely distributive and commutative subspace lattice. In this paper, we show, for a weakly closed linear subspace of a CDCSL algebra , that is a Lie ideal if and only if for all invertibles A in , and that is a Jordan ideal if and only if it is an associative ideal.     

自反代数的环自同构和环反自同构

设A为Banach空间X中一自反代数使得在LatA中O ≠0且X_≠X,则A的每一环自同构￠（环反自同构φ）具有形式￠（A）=TAT^-1(φ（A）=TA^*T^-1),其中T：X→X（T：X^*→X）或为一有界线性双射算子或为一有界共轭线性性双射算子。特别地,￠和φ都是连续的。     

自反算子代数的导子和同构

本文证明了：Ｂａｎａｃｈ空间上完全分配格代数间的导子都是自动连续的；进而证明了套代数的可加导子是内的，套代数间的代数同构是自动连续的、空间的     

Jordan Modules and Jordan Ideals of Reflexive Algebras

Let ${\mathcal{L}}$ be a completely distributive subspace lattice on a Banach space and alg ${\mathcal{L}}$ the associated reflexive algebra. Suppose that the following $$\mbox{Condition A:}\dim(F/F\wedge F_-)\ne1\;\; \mbox{for all}\;\;F\in\mathcal{L}$$ holds; note that if ${\mathcal{L}}$ is an atomic Boolean subspace lattice, this condition means that every atom of ${\mathcal{L}}$ has dimension at least two. It is shown that every reflexive Jordan Alg ${\mathcal{L}}$ -module is an associative Alg ${\mathcal{L}}$ -module. We give an example which shows that if the Condition A is removed, then the conclusion is not necessarily true. Moreover, we prove that all reflexive Jordan ideals of Alg ${\mathcal{L}}$ are associative ideals in the case that no the Condition A is assumed. The same conclusions hold for weakly closed Jordan modules and weakly closed Jordan ideals if the rank one subalgebra of Alg ${\mathcal{L}}$ is weakly dense in Alg ${\mathcal{L}}$ .     

Note on Reflexive Algebras with Non—distributive Invariant Lattices

§０．　ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔＬｂｅａｃｏｌｌｅｃｔｉｏｎｏｆｃｌｏｓｅｄｓｕｂｓｐａｃｅｓｏｆａＨｉｌｂｅｒｔｓｐａｃｅＨｃｏｎｔａｉｎｉｎｇ｛０｝ａｎｄＨｗｈｉｃｈｆｏｒｍｓａｃｏｍｐｌｅｔｅｓｕｂｓｐａｃｅｌａｔｔｉｃｅｕｎｄｅｒｔｈｅｏｐｅｒａｔｉｏｎｓ∧（ｉｎｔｅｒｓｅｃｔｉｏｎ）ａｎｄ∨（ｃｌｏｓｅｄｌｉｎｅａｒｓｐａｎ）．ＷｅｄｅｎｏｔｅｂｙａｌｇＬｔｈｅａｌｇｅｂｒａｏｆａｌｌｂｏｕｎｄｅｄｌｉｎｅａｒｏｐｅｒａｔｏｒｓｗｈｉｃｈｌｅａｖｅａｌｌｓｕｂｓｐａｃｅｓｉｎＬｉ…     

Ternary Numbers, Algebras of Reflexive Numbers and Berger Graphs

The Calabi-Yau spaces with SU(n) holonomy can be studied by the algebraic way through the integer lattice where one can construct the Newton reflexive polyhedra or the Berger graphs. Our conjecture is that the Berger graphs can be directly related with the n-ary algebras. To find such algebras we study the n-ary generalization of the well-known binary norm division algebras, , which helped to discover the most important “minimal” binary simple Lie groups, U(1), SU(2) and G(2). As the most important example, we consider the case n = 3, which gives the ternary generalization of quaternions (octonions), 3 ⁿ , n = 2, 3, respectively. The ternary generalization of quaternions is directly related to the new ternary algebra (group) which are related to the natural extensions of the binary su(3) algebra (SU(3) group). Using this ternary algebra we found the solution for the Berger graph: a tetrahedron.

“Why geniosis live so short? They wanna stay kids.”

Alexey Dubrovski: On leave from JINR, Russia. Guennadi Volkov: On leave from PNPI, Russia.     

自反算子代数的模和交换子以及一阶上同调空间

设L是赋范线性空间上的子空间格,一个子空间是自反AlgL-模的充分必要条件被得到,当L是完全分配子空间格时,自反AlgL-模的二次交换子被描述,进而,本文引入V-生成子稠格,这是一种严格地包含了完全分配格和五角格的格类。当L是可换的V-生成子稠格时,模模交换子C(AlgL;M)和代数AlgLatM都被分解成直和,并且满足条件H~1(AlgL,B(H))=0的一阶上同调空间H~1(AlgL,M)被刻划。     

Algebras of Singular Integral Operators with Piecewise Continuous Coefficients on Reflexive Orlicz Spaces

We consider singular integral operators with piecewise continuous coefficients on reflexive Orlicz spaces L_m(σ) which are generalizations of the Lebesgue spaces L_P(σ), 1 < p < ∞. We suppose that σ belongs to a large class of Carleson curves, including curves with corners and cusps as well as curves that look locally like two logarithmic spirals scrolling up at the same point. For the singular integral operator associated with the Riemann boundary value problem with a piecewise continuous coefficient G, we establish a Fredholm criterion and an index formula in terms of the essential range of G complemented by spiralic horns depending on the Boyd indices of L_M(σ) and contour properties. Our main result is a symbol calculus for the closed algebra of singular integral operators with piecewise continuous matrix - valued coefficients on L_Mⁿ(σ).     

Decomposability of Polytopes

A known characterization of the decomposability of polytopes is reformulated in a way which may be more computationally convenient, and a more transparent proof is given. New sufficient conditions for indecomposability are then deduced, and illustrated with some examples.     

f-Vectors Implying Vertex Decomposability

We prove that if a pure simplicial complex $\Delta $ of dimension $d$ with $n$ facets has the least possible number of $(d-1)$ -dimensional faces among all complexes with $n$ faces of dimension $d$ , then it is vertex decomposable. This answers a question of J. Herzog and T. Hibi. In fact, we prove a generalization of their theorem using combinatorial methods.     

Decomposability index of tournaments

Given a tournament $T$, a module of $T$ is a subset $X$ of $V\left(T\right)$ such that for $x,y\in X$ and $v\in V\left(T\right)?X$, $(x,v)\in A\left(T\right)$ if and only if $(y,v)\in A\left(T\right)$. The trivial modules of $T$ are $?$, $\left\{u\right\}$ $(u\in V\left(T\right))$ and $V\left(T\right)$. The tournament $T$ is indecomposable if all its modules are trivial; otherwise it is decomposable. The decomposability index of $T$, denoted by $\delta \left(T\right)$, is the smallest number of arcs of $T$ that must be reversed to make $T$ indecomposable. For $n\ge 5$, let $\delta \left(n\right)$ be the maximum of $\delta \left(T\right)$ over the tournaments $T$ with $n$ vertices. We prove that $?\frac{n+1}{4}?\le \delta \left(n\right)\le ?\frac{n?1}{3}?$ and that the lower bound is reached by the transitive tournaments.     

Decomposability of topological groups

We prove that every countable Abelian group with finitely many second-order elements can be decomposed into countably many subsets that are dense in any nondiscrete group topology. Lutsk Industrial Institute, Lutsk. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 51, No. 1, pp. 41–47, January, 1999.     

Decomposability of symmetric multilinear functions

Let V denote a finite dimensional vector space over a field K of characteristic 0, let T_n(V) denote the vector space whose elements are the K-valued n-linear functions on V, and let S_n(V) denote the subspace of T_n(V) whose members are the fully symmetric members of T_n(V). If $\text{L}$_n denotes the symmetric group on {1,2,…,n} then we define the projection $\text{P}{}_{\mathrm{<mtext>L</mtext>}}\text{: T}{}_{\mathrm{n}}\text{(V) → S}{}_{\mathrm{n}}\text{(V)}$ by the formula , where P_σ : T_n(V) → T_n(V) is defined so that P_σ(A)(y₁,y₂,…,y_n = A(y_σ(1),y_σ(2),…,y_σ(n)) for each A?T_n(V) and y_i?V, 1 ? i ? n. If $\text{x}{}_{\mathrm{i}}\text{? V}{}^1\text{, 1 ? i ? n}$, then x₁?x₂? … ?x_n denotes the member of T_n(V) such that $\text{(x}{}_1\text{?x}{}_2\text{· ? ? ?x}{}_{\mathrm{n}}\text{)(y}{}_1\text{,y}{}_2\text{,…,y}{}_{\mathrm{n}}\text{) = П}{}^{\mathrm{n}}{}_{\mathrm{i=1}}\text{x}{}_{\mathrm{i}}\text{(y}{}_{\mathrm{i}}\text{)}$ for each y₁ ,₂,…,y_n in V, and x₁·x₂… x_n denotes $\text{P}{}_{\mathrm{<mtext>L</mtext>}}\text{(x}{}_1\text{?x}{}_2\text{? … ?x}{}_{\mathrm{n}}\text{)}$. If B? S_n(V) and there exists $\text{x}{}_{\mathrm{i}}\text{? V}{}^1\text{, 1 ? i ? n}$, such that B = x₁·x₂…x_n, then B is said to be decomposable. We present two sets of necessary and sufficient conditions for a member B of S_n(V) to be decomposable. One of these sets is valid for an arbitrary field of characteristic zero, while the other requires that K = R or C.     

Decomposability criterion for linear sheaves

We establish a decomposability criterion for linear sheaves on ℙ ⁿ . Applying it to instanton bundles, we show, in particular, that every rank 2n instanton bundle of charge 1 on ℙ ⁿ is decomposable. Moreover, we provide an example of an indecomposable instanton bundle of rank 2n − 1 and charge 1, thus showing that our criterion is sharp.