共查询到20条相似文献,搜索用时 15 毫秒
1.
P. J. Maher 《Rendiconti del Circolo Matematico di Palermo》2007,56(3):459-463
Sea é un elemento di unaC
*-algebra tale chepa=a per qualche proiezionep, alloraa é una unitá inversa generalizzata, chiamata inversa di Moore-Penrose, e si denotata cona
+. Per leC
*-algebras, si ottiene altrest un risultato sulla minimizzazione di ∥axb−c∥.
相似文献
2.
Kazuyuki Saitô 《Rendiconti del Circolo Matematico di Palermo》2007,56(2):251-272
Every Glimm ideal of anAW
*-algebra is a (minimal) primitive ideal. 相似文献
3.
We define the reduced minimum modulus
of a nonzero element a in a unital C
*-algebra
by
. We prove that
. Applying this result to
and its closed two side ideal
, we get that dist
,
and
for any
if RR
= 0, where
and
is the quotient homomorphism and
. These results generalize corresponding results in Hilbert spaces. 相似文献
4.
Michael T. Jury 《Integral Equations and Operator Theory》2007,58(3):341-362
We analyze the essential sectrum and index theory of elements of Toeplitz-composition C*-algebras (algebras generated by the Toeplitz algebra and a single linear-fractional composition operator, acting on the Hardy
space of the unit disk). For automorphic composition operators we show that the quotient of the Toeplitz-composition algebra
by the compacts is isomorphic to the crossed product C*-algebra for the action of the symbol on the boundary circle. Using this result we obtain sufficient conditions for polynomial
elements of the algebra to be Fredholm, by analyzing the spectrum of elements of the crossed product. We also obtain an integral
formula for the Fredholm index in terms of a generalized Chern character. Finally we prove an index formula for the case of
the non-parabolic, non-automorphic linear fractional maps studied by Kriete, MacCluer and Moorhouse. 相似文献
5.
We prove a decomposition theorem for the cd-index of a Gorenstein* poset analogous to the decomposition theorem for the intersection cohomology of a toric variety. From this we settle a conjecture
of Stanley that the cd-index of Gorenstein* lattices is minimized on Boolean algebras. 相似文献
6.
Choonkil Park 《Acta Appl Math》2008,102(1):71-85
This paper is a survey on the Hyers–Ulam–Rassias stability of the following Cauchy–Jensen functional equation in C
*-algebras:
The concept of Hyers–Ulam–Rassias stability originated from the Th.M. Rassias’ stability theorem (Rassias in Proc. Am. Math.
Soc. 72:297–300, [1978]).
This work was supported by the research fund of Hanyang University (HY-2007-S). 相似文献
7.
Slightly larger than a graph<Emphasis Type="Italic">C</Emphasis><Superscript>*</Superscript>-algebra
To certain higher rank Cuntz algebras
including the classical cases we trace a certain partial isometryU in its strong closure. AdjoiningU to
we obtain a kind of uniqueness property for this largerC
*-algebra. Its explanation is not entirely “Cuntz’s uniqueness argumentation”.
The author is supported by the Austrian Research Foundation (FWF) project S8308. 相似文献
8.
We show that, if a simple C*-algebra A is topologically finite-dimensional in a suitable sense, then not only K0(A) has certain good properties, but A is even accessible to Elliott’s classification program. More precisely, we prove the following results:If A is simple, separable and unital with finite decomposition rank and real rank zero, then K0(A) is weakly unperforated.If A has finite decomposition rank, real rank zero and the space of extremal tracial states is compact and zero-dimensional, then A has stable rank one and tracial rank zero. As a consequence, if B is another such algebra, and if A and B have isomorphic Elliott invariants and satisfy the Universal coefficients theorem, then they are isomorphic.In the case where A has finite decomposition rank and the space of extremal tracial states is compact and zero-dimensional, we also give a criterion (in terms of the ordered K0-group) for A to have real rank zero. As a byproduct, we show that there are examples of simple, stably finite and quasidiagonal C*-algebras with infinite decomposition rank.Supported by: EU-Network Quantum Spaces - Noncommutative Geometry (Contract No. HPRN-CT-2002-00280) and Deutsche Forschungsgemeinschaft (SFB 478). 相似文献
9.
Using \( \mathfrak{G} \)(d, k) to denote the singular series for primes in arithmetic progressions and using the word “tail” to denote the difference of \( \mathfrak{G} \)(d, k) and its partial sums, we establish some asymptotic formulas for weighted sums of the square of the tail and so give more information on the singular series \( \mathfrak{G} \)(d, k). 相似文献
10.
Takeshi Katsura 《Acta Appl Math》2009,108(3):617-624
In this short paper, we give an explanation of the fact that the Cuntz-Krieger algebras depend only on the one-sided Markov
chains, using topological graphs and factor maps between them. 相似文献
11.
Paulina Szyszkowska 《Lithuanian Mathematical Journal》2018,58(4):500-504
In this paper, we characterize the family of quotients of internally quasicontinuous functions. Moreover, we study cardinal invariants related to quotients in the case of internally quasicontinuous functions and the complement of this family. 相似文献
12.
Alexandr S. Mishchenko 《Central European Journal of Mathematics》2005,3(4):766-793
These notes represent the subject of five lectures which were delivered as a minicourse during the VI conference in Krynica,
Poland, “Geometry and Topology of Manifolds”, May, 2–8, 2004. 相似文献
13.
We classify graph C
*-algebras, namely, Cuntz-Krieger algebras associated to the Bass-Hashimoto edge incidence operator of a finite graph, up to
strict isomorphism. This is done by a purely graph theoretical calculation of the K-theory of the C
*-algebras and the method also provides an independent proof of the classification up to Morita equivalence and stable equivalence
of such algebras, without using the boundary operator algebra. A direct relation is given between the K
1-group of the algebra and the cycle space of the graph.
We thank Jakub Byszewski for his input in Sect. 2.8. The position of the unit in K
0(
Ч) was guessed based on some example calculations by Jannis Visser in his SCI 291 Science Laboratory at Utrecht University
College. 相似文献
14.
15.
Maria Joiţa 《Czechoslovak Mathematical Journal》2004,54(3):727-737
In this paper the tensor products of Hilbert modules over locally C
*-algebras are defined and their properties are studied. Thus we show that most of the basic properties of the tensor products of Hilbert C
*-modules are also valid in the context of Hilbert modules over locally C
*-algebras. 相似文献
16.
The C
*-algebra
generated by the n poly-Bergman and m antipoly-Bergman projections and by the operators of multiplication by piecewise continuous functions on the Lebesgue space
L
2(Π) over the upper half-plane is studied. Making use of a local principle, limit operators techniques, and the Plamenevsky
results on two-dimensional convolution operators with symbols admitting homogeneous discontinuities we reduce the study to
simpler C
*-algebras associated with points
and pairs
. Applying a symbol calculus for the abstract unital C
*-algebras generated by N orthogonal projections sum of which equals the unit and by M = n + m one-dimensional orthogonal projections and using relations for the Gauss hypergeometric function, we study local algebras
at points
being the discontinuity points of coefficients. A symbol calculus for the C
*-algebra
is constructed and a Fredholm criterion for the operators
is obtained. 相似文献
17.
An atomic decomposition is proved for Banach spaces which satisfy some affine geometric axioms compatible with notions from the quantum mechanical measuring process. This is then applied to yield, under appropriate assumptions, geometric characterizations, up to isometry, of the unit ball of the dual space of a JB*-triple, and up to complete isometry, of one-sided ideals in C*-algebras.Mathematics Subject Classification (2000):17C65, 46L07Both authors are supported by NSF grant DMS-0101153 相似文献
18.
R.V. Gurjar 《Transformation Groups》2007,12(1):117-125
We will prove that any two-dimensional quotient of an affine space modulo a reductive algebraic group is isomorphic to a quotient
of C2 modulo a finite group. The proof uses some new results due to Koras and Russell on contractible surfaces with at most quotient
singularities and also several results about reductive group actions on affine varieties. 相似文献
19.
In this paper, generalized random linear mappings are viewed as random field indexed by random parameters. This point of view leads to questions about sample paths properties. We obtain various necessary and sufficient conditions ensuring the existence of nice sample paths of a generalized random linear mapping. We also give illustrative examples and applications. 相似文献
20.
Giedrius Alkauskas 《Lithuanian Mathematical Journal》2017,57(1):1-12
Consider the full modular group PSL2(?) with presentation 〈U,?S|U 3,?S 2〉. Motivated by our investigations on quasi-modular forms and the Minkowski question mark function (so that this paper may be considered as a necessary appendix), we are led to the following natural question. Some words in the alphabet {U, S} are equal to the unity; for example, USU 3 SU 2 is such a word of length 8, and USU 3 SUSU 3 S 3 U is such a word of length 15. We consider the following integer sequence. For each n ∈ ?0, let t(n) be the number of words in the alphabet {U, S} that equal the identity in the group. This is the new entry A265434 into the Online Encyclopedia of Integer Sequences. We investigate the generating function of this sequence and prove that it is an algebraic function over ?(x) of degree 3. As an interesting generalization, we formulate the problem of describing all algebraic functions with a Fermat property. 相似文献