共查询到20条相似文献,搜索用时 31 毫秒
1.
Takahiro SUDO 《数学学报(英文版)》2007,23(7):1337-1340
We study K-theory of continuous deformations of C*-algebras to obtain that their K-theory is the same as that of the fiber at zero. We also consider continuous or discontinuous deformations of Cuntz and Toeplitz algebras. 相似文献
2.
In this paper, we mainly study a family of unbounded non-hyperbolic domains in $$\mathbb {C}^{n+m}$$, called Fock–Bargmann–Hartogs domains $$D_{n,m}(\mu )$$ ($$\mu >0$$) which are defined as a Hartogs type domains with the fiber over each $$z\in \mathbb {C}^{n}$$ being a ball of radius $$e^{-\frac{\mu }{2} {\Vert z\Vert }^{2}}$$. The purpose of this paper is twofold. Firstly, we obtain necessary and sufficient conditions for Rawnsley’s $$\varepsilon $$-function $$\varepsilon _{(\alpha ,g)}(\widetilde{w})$$ of $$\big (D_{n,m}(\mu ), g(\mu ;\nu )\big )$$ to be a polynomial in $$\Vert \widetilde{w}\Vert ^2$$, where $$g(\mu ;\nu )$$ is a Kähler metric associated with the Kähler potential $$\nu \mu {\Vert z\Vert }^{2} -\ln (e^{-\mu {\Vert z\Vert }^{2}}-\Vert w\Vert ^2)$$. Secondly, using above results, we study the Berezin quantization on $$D_{n,m}(\mu )$$ with the metric $$\beta g(\mu ;\nu )$$$$(\beta >0)$$. 相似文献
3.
Certain properties of simply connected spaces with quarter pinched sectional curvature K, −4<K≤1, are considered. Additional
conditions guaranteeing that the corresponding group of isometries is a symmetric space are given.
Published inZapiski Nauchnykh Seminarov POMI, Vol. 234, 1996, pp. 39–40. 相似文献
4.
In this paper, we prove a theorem on convergence of Kähler-Ricci flow on a compact Kähler manifold which admits a Kähler-Ricci soliton.
5.
Vassili N. Kolokoltsov 《Probability Theory and Related Fields》2003,126(3):364-394
Results on existence, uniqueness, non-explosion and stochastic monotonicity are obtained for one-dimensional Markov processes
having non-local pseudo-differential generators with symbols of polynomial growth. It is proven that the processes of this
kind can be obtained as the limits of random evolutions of systems of identical indistinguishable particles with k-nary interaction.
Received: 24 May 2002 / Revised version: 19 February 2003 /
Published online: 12 May 2003
Mathematics Subject Classification (2000): 60K35, 60J75, 60J80
Key words or phrases: Interacting particles – k-nary interaction – Measure-valued processes – One-dimensional Feller processes with polynomially growing symbols – Duality
– Stochastic monotonicity – Heat kernel 相似文献
6.
Silvano Martello 《Central European Journal of Operations Research》2010,18(1):47-58
We discuss some relevant results obtained by Egerváry in the early Thirties, whose importance has been recognized several
years later. We start with a quite well-known historical fact: the first modern polynomial-time algorithm for the assignment
problem, invented by Harold W. Kuhn half a century ago, was christened the “Hungarian method” to highlight that it derives
from two older results, by Kőnig (Math Ann 77:453–465, 1916) and Egerváry (Mat Fiz Lapok 38:16–28, 1931) (A recently discovered
posthumous paper by Jacobi (1804–1851) contains however a solution method that appears to be equivalent to the Hungarian algorithm).
Our second topic concerns a combinatorial optimization problem, independently defined in satellite communication and in scheduling
theory, for which the same polynomial-time algorithm was independently published 30 years ago by various authors. It can be
shown that such algorithm directly implements another result contained in the same 1931 paper by Egerváry. We finally observe
that the latter result also implies the famous Birkhoff-von Neumann theorem on doubly stochastic matrices. 相似文献
7.
A. N. Zubkov 《Algebra and Logic》1999,38(5):299-318
Let H=Sp(n) or H=O(n); and char K≠2 in the orthogonal case. We prove that an invariant algebra K[M(n)m]H is generated by elements σi(Yj1...j2, where every matrix Yi either is Xi or the (symplectic) transpose of Xi.
Supported by RFFR grant No. 98-01-00932.
Translated fromAlgebra i Logika, Vol. 38, No. 5, pp. 549–584, September–October, 1999. 相似文献
8.
Mohamed Boulanouar 《Applications of Mathematics》2008,53(1):1-12
This paper deals with the spectral study of the streaming operator with general boundary conditions defined by means of a
boundary operator K. We study the positivity and the irreducibility of the generated semigroup proved in [M. Boulanouar, L’opérateur d’Advection:
existence d’un C
0-semi-groupe (I), Transp. Theory Stat. Phys. 31, 2002, 153–167], in the case ‖K‖ ⩾ 1. We also give some spectral properties of the streaming operator and we characterize
the type of the generated semigroup in terms of the solution of a characteristic equation. 相似文献
9.
Let κ be a semifield plane of order q4 with kernel K≅GF(q2), where q=pr, p is prime. Previously, Johnson determined the form of p-primitive semifield planes of order q4, q=pr, and Cordero specified the form of autotopisms and proved the solvability of an autotopism group for the particular case
q=p. The goal of the present article is to give an explication of the form of autotopisms and prove the solvability of an
autotopism group in the general case.
Translated fromAlgebra i Logika, Vol. 35, No. 3, pp. 334–344, May–June, 1996. 相似文献
10.
We consider an operator K˚ϕ = Lϕ−: <CDU(x), Dϕ> in a Hilbert space H, where L is an Ornstein–Uhlenbeck operator, U∈W
1,4(H, μ) and μ is the invariant measure associated with L. We show that K˚ is essentially self-adjoint in the space L
2(H, ν) where ν is the “Gibbs” measure ν(dx) = Z
−:1
e
−:2U(x)
dx. An application to Stochastic quantization is given.
Received: 13 August 1998 / Revised version: 20 September 1999 / Published online: 8 August 2000 相似文献
11.
Pablo Spiga 《Journal of Algebraic Combinatorics》2007,26(3):343-355
In this paper we prove that an elementary Abelian p-group of rank 4p−2 is not a CI(2)-group, i.e. there exists a 2-closed transitive permutation group containing two non-conjugate regular elementary Abelian
p-subgroups of rank 4p−2, see Hirasaka and Muzychuk (J. Comb. Theory Ser. A 94(2), 339–362, 2001). It was shown in Hirasaka and Muzychuk (loc cit) and Muzychuk (Discrete Math. 264(1–3), 167–185, 2003) that this is related to the problem of determining whether an elementary Abelian p-group of rank n is a CI-group.
As a strengthening of this result we prove that an elementary Abelian p-group E of rank greater or equal to 4p−2 is not a CI-group, i.e. there exist two isomorphic Cayley digraphs over E whose corresponding connection sets are not conjugate in Aut E.
This research was supported by a fellowship from the Pacific Institute for the Mathematical Sciences. 相似文献
12.
A. K. Shlyopkin 《Algebra and Logic》1998,37(5):345-350
A group G is saturated with groups of the set X if every finite subgroup K≤G is embedded in G into a subgroup L isomorphic
to some group of X. We study periodic conjugate biprimitive finite groups saturated with groups in the set {U3(2n)}. It is proved that every such group is isomorphic to a simple group U3(Q) over a locally finite field Q of characteristic 2.
Supported by the RF State Committee of Higher Education.
Translated fromAlgebra i Logika, Vol. 37, No. 5, pp. 606–615, September–October, 1998. 相似文献
13.
Friendly walkers is a stochastic model obtained from independent one-dimensional simple random walks {S
k
j
}
j≥0
, k=1,2,…,d by introducing ``non-crossing condition': and ``reward for collisions' characterized by parameters . Here, the reward for collisions is described as follows. If, at a given time n, a site in ℤ is occupied by exactly m≥2 walkers, then the site increases the probabilistic weight for the walkers by multiplicative factor exp (β
m
)≥1. We study the localization transition of this model in terms of the positivity of the free energy and describe the location
and the shape of the critical surface in the (d−1)-dimensional space for the parameters .
Received: 13 June 2002 / Revised version: 24 August 2002 Published online: 28 March 2003
Mathematics Subject Classification (2000): 82B41, 82B26, 82D60, 60G50
Key words or phrases: Random walks – Random surfaces – Lattice animals – Phase transitions – Polymers – Random walks 相似文献
14.
Gideon Maschler 《Transactions of the American Mathematical Society》2003,355(6):2161-2182
The determinant of the Ricci endomorphism of a Kähler metric is called its central curvature, a notion well-defined even in the Riemannian context. This work investigates two types of Kähler metrics in which this curvature potential gives rise to a potential for a gradient holomorphic vector field. These metric types generalize the Kähler-Einstein notion as well as that of Bando and Mabuchi (1986). Whenever possible the central curvature is treated in analogy with the scalar curvature, and the metrics are compared with the extremal Kähler metrics of Calabi. An analog of the Futaki invariant is employed, both invariants belonging to a family described in the language of holomorphic equivariant cohomology. It is shown that one of the metric types realizes the minimum of an functional defined on the space of Kähler metrics in a given Kähler class. For metrics of constant central curvature, results are obtained regarding existence, uniqueness and a partial classification in complex dimension two. Consequently, on a manifold of Fano type, such metrics and Kähler-Einstein metrics can only exist concurrently. An existence result for the case of non-constant central curvature is stated, and proved in a sequel to this work.
15.
The following results are proved. In Theorem 1, it is stated that there exist both finitely presented and not finitely presented
2-generated nonfree groups which are k-free-like for any k ⩾ 2. In Theorem 2, it is claimed that every nonvirtually cyclic (resp., noncyclic and torsion-free) hyperbolic m-generated group is k-free-like for every k ⩾ m + 1 (resp., k ⩾ m). Finally, Theorem 3 asserts that there exists a 2-generated periodic group G which is k-free-like for every k ⩾ 3.
Supported by NSF (grant Nos. DMS 0455881 and DMS-0700811). (A. Yu. Olshanskii, M. V. Sapir)
Supported by RFBR project No. 08-01-00573. (A. Yu. Olshanskii)
Supported by BSF grant (USA–Israel). (M. V. Sapir)
Translated from Algebra i Logika, Vol. 48, No. 2, pp. 245–257, March–April, 2009. 相似文献
16.
Mihály Hujter 《Central European Journal of Operations Research》2010,18(1):37-45
We survey some combinatorial results which are all related to some former results of ours, and, at the same time, they are
all related to the famous Kőnig–Egerváry theorem from 1931. 相似文献
17.
Anders Skovsted Buch Andrew Kresch Mark Shimozono Harry Tamvakis Alexander Yong 《Mathematische Annalen》2008,340(2):359-382
We formulate a nonrecursive combinatorial rule for the expansion of the stable Grothendieck polynomials of Fomin and Kirillov
(Proc Formal Power Series Alg Comb, 1994) in the basis of stable Grothendieck polynomials for partitions. This gives a common
generalization, as well as new proofs of the rule of Fomin and Greene (Discret Math 193:565–596, 1998) for the expansion of
the stable Schubert polynomials into Schur polynomials, and the K-theoretic Grassmannian Littlewood–Richardson rule of Buch (Acta Math 189(1):37–78, 2002). The proof is based on a generalization
of the Robinson–Schensted and Edelman–Greene insertion algorithms. Our results are applied to prove a number of new formulas
and properties for K-theoretic quiver polynomials, and the Grothendieck polynomials of Lascoux and Schützenberger (C R Acad Sci Paris Ser I Math
294(13):447–450, 1982). In particular, we provide the first K-theoretic analogue of the factor sequence formula of Buch and Fulton (Invent Math 135(3):665–687, 1999) for the cohomological
quiver polynomials. 相似文献
18.
Functional data analysis, as proposed by Ramsay (Psychometrika 47:379–396, 1982), has recently attracted many researchers.
The most popular approach taken in recent studies of functional data has been the extension of statistical methods for the
analysis of usual data to that of functional data (e.g., Ramsay and Silverman in Functional data Analysis Springer, Berlin
Heidelberg New York, 1997, Applied functional data analysis: methods and case studies. Springer, Berlin Heidelberg New York,
2002; Mizuta in Proceedings of the tenth Japan and Korea Joint Conference of Statistics, pp 77–82, 2000; Shimokawa et al.
in Japan J Appl Stat 29:27–39, 2000). In addition, several methods for clustering functional data have been proposed (Abraham
et al. in Scand J Stat 30:581–595, 2003; Gareth and Catherine in J Am Stat Assoc 98:397–408, 2003; Tarpey and kinateder in
J Classif 20:93–114, 2003; Rossi et al. in Proceedings of European Symposium on Artificial Neural Networks pp 305–312, 2004).
Furthermore, Tokushige et al. (J Jpn Soc Comput Stat 15:319–326, 2002) defined several dissimilarities between functions for
the case of functional data. In this paper, we extend existing crisp and fuzzy k-means clustering algorithms to the analysis of multivariate functional data. In particular, we consider the dissimilarity
between functions as a function. Furthermore, cluster centers and memberships, which are defined as functions, are determined
at the minimum of a certain target function by using a calculus-of-variations approach. 相似文献
19.
P. Danchev 《Lithuanian Mathematical Journal》2007,47(2):129-134
We prove the following theorem: Any abelian p-group is an n-Σ-group which is a strong ω-elongation of a totally projective group by a p
ω+n
-projective group precisely when it is totally projective. In particular, each p-torsion p
ω+n
-projective n-Σ-group is a direct sum of countable p-groups of length not exceeding ω + n and vice versa. These two claims generalize our recent results in [6] and [7].
Published in Lietuvos Matematikos Rinkinys, Vol. 47, No. 2, pp. 155–162, April–June, 2007. 相似文献
20.
T. S. Kopaliani 《Ukrainian Mathematical Journal》2008,60(12):2006-2014
We point out that if the Hardy–Littlewood maximal operator is bounded on the space L
p(t)(ℝ), 1 < a ≤ p(t) ≤ b < ∞, t ∈ ℝ, then the well-known characterization of the spaces L
p
(ℝ), 1 < p < ∞, by the Littlewood–Paley theory extends to the space L
p(t)(ℝ). We show that, for n > 1 , the Littlewood–Paley operator is bounded on L
p(t) (ℝ
n
), 1 < a ≤ p(t) ≤ b < ∞, t ∈ ℝ
n
, if and only if p(t) = const.
Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 60, No. 12, pp. 1709–1715, December, 2008. 相似文献