共查询到20条相似文献,搜索用时 15 毫秒
1.
Hengwu Zheng 《Semigroup Forum》2011,83(3):457-467
As a generalization of Preston’s kernel normal systems, P\mathcal{P}-kernel normal systems for P\mathcal{P}-inversive semigroups are introduced, and strongly regular P\mathcal{P}-congruences on P\mathcal{P}-inversive semigroups in terms of their P\mathcal{P}-kernel normal systems are characterized. These results generalize the corresponding results for P\mathcal{P}-regular semigroups and P\mathcal{P}-inversive semigroups. 相似文献
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4.
Dong Zhe 《Czechoslovak Mathematical Journal》2006,56(2):287-298
In this paper we investigate finite rank operators in the Jacobson radical
of Alg(
), where
are nests. Based on the concrete characterizations of rank one operators in Alg(
) and
, we obtain that each finite rank operator in
can be written as a finite sum of rank one operators in
and the weak closure of
equals Alg(
) if and only if at least one of
is continuous. 相似文献
5.
The appearance of the theory of zero-knowledge, presented by Goldwasser, Micali and Rackoff in 1985, opened a way to secure identification schemes. The first application was the famous Fiat-Shamir scheme based on the problem of modular square roots extraction. In the following years, many other schemes have been proposed, some Fiat-Shamir extensions but also new discrete logarithm based schemes. Therefore, all of them were based on problems from number theory. Their main common drawback is high computational load because of arithmetical operations modulo large integers. Implementation on low-cost smart cards was made difficult and inefficient.With the Permuted Kernels Problem (PKP), Shamir proposed the first efficient scheme allowing for an implementation on such low-cost smart cards, but very few others have afterwards been suggested.In this paper, we present an efficient identification scheme based on a combinatorial
-complete problem: the Permuted Perceptrons Problem (PPP). This problem seems hard enough to be unsolvable even with very small parameters, and some recent cryptanalysis studies confirm that position. Furthermore, it admits efficient zero-knowledge proofs of knowledge and so it is well-suited for cryptographic purposes. An actual implementation completes the optimistic opinion about efficiency and practicability on low-cost smart cards, and namely with less than 2KB of EEPROM and just 100 Bytes of RAM and 6.4 KB of communication. 相似文献
6.
$
\mathcal{I}_g
$
\mathcal{I}_g
-normal and $
\mathcal{I}_g
$
\mathcal{I}_g
-regular spaces are introduced and various characterizations and properties are given. Characterizations of normal, mildly
normal, g-normal, regular and almost regular spaces are also given. 相似文献
7.
We investigate the partition property of ${\mathcal{P}_{\kappa}\lambda}$ . Main results of this paper are as follows: (1) If λ is the least cardinal greater than κ such that ${\mathcal{P}_{\kappa}\lambda}$ carries a (λ κ , 2)-distributive normal ideal without the partition property, then λ is ${\Pi^1_n}$ -indescribable for all n?<?ω but not ${\Pi^2_1}$ -indescribable. (2) If cf(λ) ≥?κ, then every ineffable subset of ${\mathcal{P}_{\kappa}\lambda}$ has the partition property. (3) If cf(λ) ≥ κ, then the completely ineffable ideal over ${\mathcal{P}_{\kappa}\lambda}$ has the partition property. 相似文献
8.
We introduce a planar waveguide of constant width with non-Hermitian -symmetric Robin boundary conditions. We study the spectrum of this system in the regime when the boundary coupling function
is a compactly supported perturbation of a homogeneous coupling. We prove that the essential spectrum is positive and independent
of such perturbation, and that the residual spectrum is empty. Assuming that the perturbation is small in the supremum norm,
we show that it gives rise to real weakly-coupled eigenvalues converging to the threshold of the essential spectrum. We derive
sufficient conditions for these eigenvalues to exist or to be absent. Moreover, we construct the leading terms of the asymptotic
expansions of these eigenvalues and the associated eigenfunctions.
相似文献
9.
We compute the space of Poisson traces on a classical W \mathcal{W} -algebra, i.e., linear functionals invariant under Hamiltonian derivations. Modulo any central character, this space identifies
with the top cohomology of the corresponding Springer fiber. As a consequence, we deduce that the zeroth Hochschild homology
of the corresponding quantum W \mathcal{W} -algebra modulo a central character identifies with the top cohomology of the corresponding Springer fiber. This implies that
the number of irreducible finite-dimensional representations of this algebra is bounded by the dimension of this top cohomology,
which was established earlier by C. Dodd using reduction to positive characteristic. Finally, we prove that the entire cohomology
of the Springer fiber identifies with the so-called Poisson-de Rham homology (defined previously by the authors) of the centrally
reduced classical W \mathcal{W} -algebra. 相似文献
10.
Patrice P. Ntumba 《Rendiconti del Circolo Matematico di Palermo》1936,60(1-2):173-180
As for the classical complexification of real vector spaces, the sheaf-theoretic version shows that free \(\mathcal{A}\)-modules of finite rank, with \(\mathcal{A}\) an ordered nonzero-nilsquare free ?-algebra sheaf, admits a complex structure if and only if there exists on \(\mathcal{E}\) an \(\mathcal{A}\)-automorphism J such that J 2=?I. 相似文献
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V. Renukadevi 《Acta Mathematica Hungarica》2009,122(4):329-338
We characterize and discuss the properties of $
\mathcal{I}R
$
\mathcal{I}R
-closed sets and $
A_{\mathcal{I}R}
$
A_{\mathcal{I}R}
-sets. Also, we give characterizations of weakly $
\mathcal{I}
$
\mathcal{I}
-locally closed sets and $
\mathcal{I}
$
\mathcal{I}
-submaximal spaces. A characterization of codense ideals in terms of $
\mathcal{I}R
$
\mathcal{I}R
-closed sets is also given. 相似文献
14.
Let G be a connected graph. For at distance 2, we define , and , if then . G is quasi-claw-free if it satisfies , and G is P
3-dominated() if it satisfies , for every pair (x, y) of vertices at distance 2. Certainly contains as a subclass. In this paper, we prove that the circumference of a 2-connected P
3-dominated graph G on n vertices is at least min or , moreover if then G is hamiltonian or , where is a class of 2-connected nonhamiltonian graphs. 相似文献
15.
Mario Petrich 《Semigroup Forum》2008,77(2):227-247
A nontrivial regular semigroup S with zero in which every interval of idempotents is a finite chain is said to be
-regular. The structure of these semigroups is described in terms of trees of completely 0-simple semigroups. For S in this form, we study congruences which we express in terms of congruence aggregates.
We determine the inclusion relation, meet and join of congruences, their kernel and trace, and the ends of the intervals which
form their classes. We characterize those S for which the kernel relation on the congruence lattice is a congruence, and those for which the operators
and
are homomorphisms. 相似文献
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17.
Hongliang Yao 《Proceedings Mathematical Sciences》2010,120(2):199-207
Lin and Su classified A$
\mathcal{T}
$
\mathcal{T}
-algebras of real rank zero. This class includes all A$
\mathbb{T}
$
\mathbb{T}
-algebras of real rank zero as well as many C*-algebras which are not stably finite. An A$
\mathcal{T}
$
\mathcal{T}
-algebra often becomes an extension of an A$
\mathbb{T}
$
\mathbb{T}
-algebra by an AF-algebra. In this paper, we show that there is an essential extension of an A$
\mathbb{T}
$
\mathbb{T}
-algebra by an AF-algebra which is not an A$
\mathcal{T}
$
\mathcal{T}
-algebra. We describe a characterization of an extension E of an A$
\mathbb{T}
$
\mathbb{T}
-algebra by an AF-algebra if E is an A$
\mathcal{T}
$
\mathcal{T}
-algebra. 相似文献
18.
D. H. Kochloukova 《Monatshefte für Mathematik》2014,175(3):367-384
Let \({\mathcal {C}}\) be a class of finite groups. We study some sufficient conditions for the pro- \({\mathcal {C}}\) completion of an orientable \(\text{ PD }^3\) -pair over \(\mathbb {Z}\) to be an orientable profinite \(\text{ PD }^3\) -pair over \(\mathbb {F}_p\) . More results are proven for the pro- \(p\) completion of \(\text{ PD }^3\) -pairs. 相似文献
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A. V. Kravchenko 《Algebra and Logic》2002,41(3):173-181
It is proved that a quasivariety K of undirected graphs without loops is
-universal if and only if K contains some non-bipartite graph. 相似文献