The Blok–Ferreirim theorem for normal GBL-algebras and its application

Generalized basic logic algebras (GBL-algebras for short) have been introduced in [JT02] as a generalization of Hájek’s BL-algebras, and constitute a bridge between algebraic logic and ℓ-groups. In this paper we investigate normal GBL-algebras, that is, integral GBL-algebras in which every filter is normal. For these structures we prove an analogue of Blok and Ferreirim’s [BF00] ordinal sum decomposition theorem. This result allows us to derive many interesting consequences, such as the decidability of the universal theory of commutative GBL-algebras, the fact that n-potent GBL-algebras are commutative, and a representation theorem for finite GBL-algebras as poset sums of GMV-algebras, a result which generalizes Di Nola and Lettieri’s [DL03] representation of finite BL-algebras. Presented by J. G. Raftery. Received May 23, 2007; accepted in final form February 20, 2008.     

Tarski monoids: Matui’s spatial realization theorem

This paper continues the study of a class of inverse monoids, called Tarski monoids, that can be regarded as non-commutative generalizations of the unique countable, atomless Boolean algebra. These inverse monoids are related to a class of étale topological groupoids under a non-commutative generalization of classical Stone duality and, significantly, they arise naturally in the theory of dynamical systems as developed by Matui. We are thereby able to reinterpret a theorem of Matui (à la Rubin) on a class of étale groupoids as an equivalent theorem about a class of Tarski monoids: two simple Tarski monoids are isomorphic if and only if their groups of units are isomorphic. The inverse monoids in question may also be viewed as countably infinite generalizations of finite symmetric inverse monoids. Their groups of units therefore generalize the finite symmetric groups and include amongst their number the Thompson groups \(V_{n}\).     

Dimension polynomials in the generalized difference case

The aim of this paper is to generalize results on dimension polynomials of difference modules over difference rings for a wider class of rings of difference operators. We introduce the notion of quasi-commutativity, which generalizes the notion of commutativity and enables one to consider wider classes of monoids and groups of endomorphisms. Some properties of quasi-commutative monoids and groups are established; these properties allow us to apply some methods that are almost similar to the ones used in working with free commutative monoids and groups. Also we prove the theorem of existence of the dimension polynomial of generalized difference modules in the cases where the submonoid of endomorphisms is free quasi-commutative. Also the existence of its analog for the case of a direct product of a free quasi-commutative monoid and a finite cyclic group is established.     

Probabilistic Averaging in Bounded Rℓ-Monoids

Bounded Rℓ-monoids generalize GMV-algebras and pseudo BL-algebras. Such monoids do not admit, in general, any analogue of addition, in contrast to GMV-algebras. Nevertheless we introduce the notion of a state (an analogue of a probability measure). It coincides with that for GMV-algebras. We show that the existence of states is crucially connected with the existence of normal and maximal filters. In addition, some topological properties of the extremal states and the hull-kernel topology of filters are studied.     

Higher spin generalisation of Fueter's theorem

In this paper, we generalize Fueter's theorem to the higher spin setting. To do so, we consider an alternative proof for the celebrated theorem that uses the Fischer decomposition. This decomposition is then extended to spaces of polynomials that depend on wedge variables, after which we can finish the proof of our higher spin Fueter theorem.     

幺半群左正则纯整半直积上的同余

研究了幺半群半直积上的同余，给出了幺半群半直积的所谓同余分解定理，并特别讨论了幺半群左正则纯整半直积及其子类上的同余．     

Embedding theorems for classes of GBL-algebras

The poset product construction is used to derive embedding theorems for several classes of generalized basic logic algebras (GBL-algebras). In particular it is shown that every n-potent GBL-algebra is embedded in a poset product of finite n-potent MV-chains, and every normal GBL-algebra is embedded in a poset product of totally ordered GMV-algebras. Representable normal GBL-algebras have poset product embeddings where the poset is a root system. We also give a Conrad-Harvey-Holland-style embedding theorem for commutative GBL-algebras, where the poset factors are the real numbers extended with −∞. Finally, an explicit construction of a generic commutative GBL-algebra is given, and it is shown that every normal GBL-algebra embeds in the conucleus image of a GMV-algebra.     

AF inverse monoids and the structure of countable MV-algebras

This paper is a further contribution to the developing theory of Boolean inverse monoids. These monoids should be regarded as non-commutative generalizations of Boolean algebras; indeed, classical Stone duality can be generalized to this non-commutative setting to yield a duality between Boolean inverse monoids and a class of étale topological groupoids. MV-algebras are also generalizations of Boolean algebras which arise from many-valued logics. It is the goal of this paper to show how these two generalizations are connected. To do this, we define a special class of Boolean inverse monoids having the property that their lattices of principal ideals naturally form an MV-algebra. We say that an arbitrary MV-algebra can be co-ordinatized if it is isomorphic to an MV-algebra arising in this way. Our main theorem is that every countable MV-algebra can be so co-ordinatized. The particular Boolean inverse monoids needed to establish this result are examples of what we term AF inverse monoids and are the inverse monoid analogues of AF $C^{?}$-algebras. In particular, they are constructed from Bratteli diagrams as direct limits of finite direct products of finite symmetric inverse monoids.     

Decomposition results for stochastic storage processes and queues with alternating Lévy inputs

In this paper we generalize known workload decomposition results for Lévy queues with secondary jump inputs and queues with server vacations or service interruptions. Special cases are polling systems with either compound Poisson or more general Lévy inputs. Our main tools are new martingale results, which have been derived in a companion paper.     

Arithmetic of Mori domains and monoids

In this paper we introduce weakly C-monoids as a new class of v-noetherian monoids. Weakly C-monoids generalize C-monoids and make it possible to study multiplicative properties of a wide class of Mori domains, e.g., rings of generalized power series with coefficients in a field and exponents in a finitely generated monoid. The main goal of the paper is to study the question when a weakly C-monoid is locally tame. After having proved a classification theorem for local tameness, we use it to show that every locally tame weakly C-monoid whose complete integral closure has finite class group has finite catenary degree and finite set of distances.     

Decomposition of transformations

The decomposition theorem for transformations without any additivity assumptions is proved. This result is new even for image transformations. We also introduce a new class of transformations with some additivity assumpt ions which includes image transformations. Using the transformation from this class we generalize the Aarnes factorization theorem to representable deficient topological measures. We also establish the relationship between the decomposition of a representable deficient topological measure and the decomposition of the transformation mentioned above.     

Slice theorem and orbit type stratification in infinite dimensions

We establish a general slice theorem for the action of a locally convex Lie group on a locally convex manifold, which generalizes the classical slice theorem of Palais to infinite dimensions. We discuss two important settings under which the assumptions of this theorem are fulfilled. First, using Glöckner's inverse function theorem, we show that the linear action of a compact Lie group on a Fréchet space admits a slice. Second, using the Nash–Moser theorem, we establish a slice theorem for the tame action of a tame Fréchet Lie group on a tame Fréchet manifold. For this purpose, we develop the concept of a graded Riemannian metric, which allows the construction of a path-length metric compatible with the manifold topology and of a local addition. Finally, generalizing a classical result in finite dimensions, we prove that the existence of a slice implies that the decomposition of the manifold into orbit types of the group action is a stratification.     

Helly-type theorems for pseudoline arrangements in P2

We prove duals of Radon's theorem, Helly's theorem, Carathéodory's theorem, and Kirchberger's theorem for arrangements of pseudolines in the real projective plane, which generalize the original versions of those theorems for plane configurations of points. We also prove a topological generalization of the pseudoline-dual of Helly's theorem.     

A characterization of Lévy probability distribution functions on Euclidean spaces

In 1937, Paul Lévy proved two theorems that characterize one-dimensional distribution functions of class L. In 1972, Urbanik generalized Lévy's first theorem. In this note, we generalize Lévy's second theorem and obtain a new characterization of Lévy probability distribution functions on Euclidean spaces. This result is used to obtain a new characterization of operator stable distribution functions on Euclidean spaces and to show that symmetric Lévy distribution functions on Euclidean spaces need not be symmetric unimodal.     

From an iteration formula to Poincaré's Isochronous Center Theorem for holomorphic vector fields

We first generalize a classical iteration formula for one variable holomorphic mappings to a formula for higher dimensional holomorphic mappings. Then, as an application, we give a short and intuitive proof of a classical theorem, due to H. Poincaré, for the condition under which a singularity of a holomorphic vector field is an isochronous center.

     

独异点的同构定理和独异点列

随着自动机理论的发展,独异点(monoid,即含单位元的半群)理论得到了重要的应用,其地位也日益提高。虽然,作为泛代数(universal algebra)的特例之独异点的同构定理等早巳随着泛代数有关定理的给出(见[1],[2])而给出了,但其反映不出独异点的特点。特别是如何把独异点与群在这方面统一地描述出来,更是许多人所关注的问题。Jacobson在[3]内就这样做了,但很不完美;[4]就一种极特殊的情形,给出了     

The classification of (J, σ)-irreducible monoids of type A 4

In this paper we develop a very basic method to classify (J, σ)-irreducible monoids of type A ₄. As a typical example, we list all the types for the monoids corresponding to the strongly dominant weights. This example also shows that there is no general theorem to determine the cross-section lattices for reductive monoids according to their Dynkin diagrams as Putcha and Renner’s recipe for J-irreducible monoids.     

Tensor product of partially-additive monoids

Partially-additive monoids (pams) were introduced by Arbib and Manes in order to provide an algebraic semantics for programming languages. In this paper, we prove that the categoryP a m of pams and additive maps is a closed category whose monoids are partially-additive semirings. We follow the tensor product construction of R. Guitart [7] for categories of algebras which generalize the case of modules. Nevertheless, the problem here is more difficult owing to the fact that pams are partial algebras rather than algebras. Thus, we have to make some modifications to Guitart’s approach.     

Poisson Lie Groups and Non-Linear Convexity Theorems

In this paper we describe how one can derive nonlinear convexity theorems which are similar to Kostant's nonlinear convexity theorem for the Iwasawa decomposition from Hamiltonian actions on Poisson Lie groups. Our results generalize those of LU and Ratiu ([24]) and aim at a unified symplectic framework for the convexity theorem in [32] and the linear convexity theorems for coadjoint orbits of convex type in [15].     

Almost sure convergence of weighted partial sums

Sufficient conditions of covariance type are presented for weighted averages of random variables with arbitrary dependence structure to converge to 0, both for logarithmic and general weighting. As an application, an a.s. local limit theorem of Csáki, Földes and Révész is revisited and slightly improved.