arXiv subjects

Anatolij Dvurečenskij

Publications and source records attributed to Anatolij Dvurečenskij.

At least 19 recordsLinked to original sources

arXiv2023

Representation and Embedding of Pseudo MV-algebras with Square Roots I. Strict Square Roots

In \cite{DvZa3}, we started the investigation of pseudo MV-algebras with square roots. In the present paper, we continue to study the structure of pseudo MV-algebras with square roots focusing on their new characterizations. The paper is divided into two parts. In the present first part, we investigate the relationship between a pseudo MV-algebra with square root and its corresponding unital $\ell$-group in the scene of two-divisibility. In the second part, we find some conditions under which a particular class of pseudo MV-algebras can be embedded into pseudo MV-algebras with square roots. We introduce and investigate the concepts of a strict square root of a pseudo MV-algebra and a square root closure, and we compare both notions. We show that each MV-algebra has a square root closure. Finally, using the square root of individual elements of a pseudo MV-algebra, we find the greatest subalgebra of a special pseudo MV-algebra with weak square root.

math.RA↗

arXiv2023

Representation and Embedding of Pseudo MV-algebras with Square Roots II. Closures

In \cite{DvZa3}, we started the investigation of pseudo MV-algebras with square roots. In the present paper, the main aim is to continue to study the structure of pseudo MV-algebras with square roots focusing on their new characterizations. The paper is divided into two parts. In the first part, we investigate the relationship between a pseudo MV-algebra with square root and its corresponding unital $\ell$-group in the scene of two-divisibility. In the present second part, we find some conditions under which a particular class of pseudo MV-algebras can be embedded into pseudo MV-algebras with square roots. We introduce and investigate the concepts of a strict square root of a pseudo MV-algebra and a square root closure, and we compare both notions. We show that each MV-algebra has a square root closure. Finally, using the square root of individual elements of a pseudo MV-algebra, we find the greatest subalgebra of a special pseudo MV-algebra with weak square root.

math.RA↗

arXiv2022

Some results on pseudo MV-algebras with square roots

The paper provides a study of pseudo MV-algebras with square roots. We introduce different notions of a square root on a pseudo MV-algebra, and present their main properties. We show that the class of pseudo-MV-algebras with square roots is a proper subvariety of the variety of pseudo MV-algebras. Then, we define a strict square root to classify the class of pseudo MV-algebras with square roots. We found a relationship between strongly atomless pseudo MV-algebras and strict pseudo MV-algebras. Finally, we investigate square roots on representable symmetric pseudo MV-algebras, and we present a complete characterization of a square root and a weak square root on a representable symmetric pseudo MV-algebra using addition in a unital $\ell$-group. Some interesting examples are provided.

math.AC↗

arXiv2022

On EMV-algebras with square roots

A square root is a unary operation with some special properties. In the paper, we introduce and study square roots on EMV-algebras. First, the known properties of square roots defined on MV-algebras will be generalized for EMV-algebras, and we also find some new ones for MV-algebras. We use square roots to characterize EMV-algebras. Then, we find a relation between the square root of an EMV-algebra and the square root on its representing EMV-algebra with top element. We show that each strict EMV-algebra has a top element and we investigate the relation between divisible EMV-algebras and EMV-algebras with a special square root. Finally, we present square roots on tribes, EMV-tribes, and we present a complete characterization of any square root on an MV-algebra and on an EMV-algebra by group addition in the corresponding unital $\ell$-group.

math.RA↗

arXiv2020

$n$-dimensional Observables on $k$-Perfect MV-Algebras and $k$-Perfect Effect Algebras. I. Characteristic Points

In the paper, we investigate a one-to-one correspondence between $n$-dimensional observables and $n$-dimensional spectral resolutions with values in a kind of a lexicographic form of quantum structures like perfect MV-algebras or perfect effect algebras. The multidimensional version of this problem is more complicated than a one-dimensional one because if our algebraic structure is $k$-perfect for $k>1$, then even for the two-dimensional case we have more characteristic points. The obtained results are also applied to existence of an $n$-dimensional meet joint observable of $n$ one-dimensional observables on a perfect MV-algebra. The results are divided into two parts. In Part I, we present notions of $n$-dimensional observables and $n$-dimensional spectral resolutions with accent on lexicographic type effect algebras and lexicographic MV-algebras. We concentrate on characteristic points of spectral resolutions and the main body is in Part II where one-to-one relations between observables and spectral resolutions are presented.

math.FA↗

arXiv2020

$n$-dimensional Observables on $k$-Perfect MV-Algebras and $k$-Perfect Effect Algebras. II. One-to-one Correspondence

The paper is a continuation of the research on a one-to-one correspondence between $n$-dimensional spectral resolutions and $n$-dimensional observables on lexicographic types of quantum structures which started in \cite{DvLa4}. In Part I, we presented the main properties of $n$-dimensional spectral resolutions and observables, and we deeply studied characteristic points which are crucial for our study. In present Part II, there is a main body of our research. We investigate a one-to-one correspondence between $n$-dimensional observables and $n$-dimensional spectral resolutions with values in a kind of a lexicographic form of quantum structures like perfect MV-algebras or perfect effect algebras. The multidimensional version of this problem is more complicated than a one-dimensional one because if our algebraic structure is $k$-perfect for $k>1$, then even for the two-dimensional case of spectral resolutions we have more characteristic points. The obtained results are applied to existence of an $n$-dimensional meet joint observable of $n$ one-dimensional observables on a perfect MV-algebra and a sum of $n$-dimensional observables.

math.FA↗

arXiv2020

Lifting, $n$-Dimensional Spectral Resolutions, and $n$-Dimensional Observables

We show that under some natural conditions, we are able to lift an $n$-dimensional spectral resolution from one monotone $σ$-complete unital po-group into another one, when the first one is a $σ$-homomorphic image of the second one. We note that an $n$-dimensional spectral resolution is a mapping from $\mathbb R^n$ into a quantum structure which is monotone, left-continuous with non-negative increments and which is going to $0$ if one variable goes to $-\infty$ and it goes to $1$ if all variables go to $+\infty$. Applying this result to some important classes of effect algebras including also MV-algebras, we show that there is a one-to-one correspondence between $n$-dimensional spectral resolutions and $n$-dimensional observables on these effect algebras which are a kind of $σ$-homomorphisms from the Borel $σ$-algebra of $\mathbb R^n$ into the quantum structure. An important used tool are two forms of the Loomis--Sikorski theorem which use two kinds of tribes of fuzzy sets. In addition, we show that we can define three different kinds of $n$-dimensional joint observables of $n$ one-dimensional observables.

math.AC↗

arXiv2019

A Variety Containing EMV-Algebras and Pierce Sheaves

According to \cite{Dvz}, we know that the class of all EMV-algebras, $\mathsf{EMV}$, is not a variety, since it is not closed under the subalgebra operator. The main aim of this work is to find the least variety containing $\mathsf{EMV}$. For this reason, we introduced the variety $\mathsf{wEMV}$ of wEMV-algebras of type $(2,2,2,2,0)$ induced by some identities. We show that, adding a derived binary operation $\ominus$ to each EMV-algebra $(M;\vee,\wedge,\oplus,0)$, we extend its language, so that $(M;\vee,\wedge,\oplus,\ominus,0)$, called an associated wEMV-algebra, belongs to $\mathsf{wEMV}$. Then using the congruence relations induced by the prime ideals of a wEMV-algebra, we prove that each wEMV-algebra can be embedded into an associated wEMV-algebra. We show that $\mathsf{wEMV}$ is the least subvariety of the variety of wEMV-algebras containing $\mathsf{EMV}$. Finally, we study Pierce sheaves of proper EMV-algebras.

math.RA↗

arXiv2017

Morphisms on $EMV$-algebras and Their Applications

For a new class of algebras, called $EMV$-algebras, every idempotent element $a$ determines an $MV$-algebra which is important for the structure of the $EMV$-algebra. Therefore, instead of standard homomorphisms of $EMV$-algebras, we introduce $EMV$-morphisms as a family of $MV$-homomorphisms from $MV$-algebras $[0,a]$ into other ones. $EMV$-morphisms enable us to study categories of $EMV$-algebras where objects are $EMV$-algebras and morphisms are special classes of $EMV$-morphisms. The category is closed under product. In addition, we define free $EMV$-algebras on a set $X$ with respect to $EMV$-morphisms. If $X$ is finite, then the free $MV$-algebra on $X$ is a free $EMV$-algebras. For an infinite set $X$, the same is true introducing a so-called weakly free $EMV$-algebra.

math.AC↗

arXiv2017

Riesz space-valued states on pseudo MV-algebras

We introduce Riesz space-valued states, called $(R,1_R)$-states, on a pseudo MV-algebra, where $R$ is a Riesz space with a fixed strong unit $1_R$. Pseudo MV-algebras are a non-commutative generalization of MV-algebras. Such a Riesz space-valued state is a generalization of usual states on MV-algebras. Any $(R,1_R)$-state is an additive mapping preserving a partial addition in pseudo MV-algebras. Besides we introduce $(R,1_R)$-state-morphisms and extremal $(R,1_R)$-states, and we study relations between them. We study metrical completion of unital $\ell$-groups with respect to an $(R,1_R)$-state. If the unital Riesz space is Dedekind complete, we study when the space of $(R,1_R)$-states is a Choquet simplex or even a Bauer simplex.

math.AC↗

arXiv2017

States on EMV-algebras

We define a state as a $[0,1]$-valued, finitely additive function attaining the value $1$ on an EMV-algebra, which is an algebraic structure close to MV-algebras, where the top element is not assumed. We show that states always exist, the extremal states are exactly state-morphisms. Nevertheless the state space is a convex space that is not necessarily compact, a variant of the Krein--Mil'man theorem saying states are generated by extremal states, is proved. We define a weaker form of states, pre-states and strong pre-states, and also Jordan signed measures which form a Dedekind complete $\ell$-group. Finally, we show that every state can be represented by a unique regular probability measure, and a variant of the Horn--Tarski theorem is proved.

math.LO↗

arXiv2017

Kites and Residuated Lattices

We investigate a construction of an integral residuated lattice starting from an integral residuated lattice and two sets with an injective mapping from one set into the second one. The resulting algebra has a shape of a Chinese cascade kite, therefore, we call this algebra simply a kite. We describe subdirectly irreducible kites and we classify them. We show that the variety of integral residuated lattices generated by kites is generated by all finite-dimensional kites. In particular, we describe some homomorphisms among kites.

math.RA↗

arXiv2017

The Loomis--Sikorski Theorem for $EMV$-algebras

Recently, in [DvZa], we have introduced $EMV$-algebras which resemble $MV$-algebras but the top element is not guaranteed for them. For $σ$-complete $EMV$-algebras, we prove an analogue of the Loomis--Sikorski Theorem showing that every $σ$-complete $EMV$-algebra is a $σ$-homomorphic image of an $EMV$-tribe of fuzzy sets where all algebraic operations are defined by points. To prove it, some topological properties of the state-morphism space and the space of maximal ideals are established.

math.AC↗

arXiv2017

On EMV-algebras

The paper deals with an algebraic extension of $MV$-algebras based on the definition of generalized Boolean algebras. We introduce a new algebraic structure, not necessarily with a top element, which is called an $EMV$-algebra and every $EMV$-algebra contains an $MV$-algebra. First, we present basic properties of $EMV$-algebras, give some examples, introduce and investigate congruence relations, ideals and filters on this algebra. We show that each $EMV$-algebra can be embedded into an $MV$-algebra and we characterize $EMV$-algebras either as $MV$-algebras or maximal ideals of $MV$-algebras. We study the lattice of ideals of an $EMV$-algebra and prove that any $EMV$-algebra has at least one maximal ideal. We define an $EMV$-clan of fuzzy sets as a special $EMV$-algebra. We show any semisimple $EMV$-algebra is isomorphic to an $EMV$-clan of fuzzy functions on a set. We consider the variety of $EMV$-algebra and we present an equational base for each proper subvariety of the variety of $EMV$-algebras. We establish a categorical equivalencies of the category of proper $EMV$-algebras, the category of $MV$-algebras with a fixed special maximal ideal, and a special category of Abelian unital $\ell$-groups.

math.AC↗

arXiv2016

Sum of Observables on MV-Effect Algebras

Using a one-to-one correspondence between observables and their spectral resolutions, we introduce the sum of any two bounded observables of a $σ$-MV-effect algebra. This sum is commutative, associative and with neutral element. Under the Olson order of observables, the set of bounded observables is a partially ordered semigroup, and the set of sharp observables is even a Dedekind $σ$-complete $\ell$-group with strong unit.

math.FA↗

arXiv2016

Quantum Observables and Effect Algebras

We study observables on monotone $σ$-complete effect algebras. We find conditions when a spectral resolution implies existence of the corresponding observable. The set of sharp elements of a monotone $σ$-complete homogeneous effect algebra is a monotone $σ$-complete subalgebra. In addition, we study compatibility in orthoalgebras.

math-ph↗

arXiv2016

On epicomplete $MV$-algebras

The aim of the paper is to study epicomplete objects in the category of $MV$-algebras. A relation between injective $MV$-algebras and epicomplete $MV$-algebras is found, an equivalence condition for an $MV$-algebra to be epicomplete is obtained, and it is shown that the class of divisible $MV$-algebras and the class of epicomplete $MV$-algebras are the same. Finally, the concept of an epicompletion for $MV$-algebras is introduced, and the conditions under which an $MV$-algebra has an epicompletion are obtained. As a result we show that each $MV$-algebra has an epicompletion.

math.AC↗

arXiv2016

When Lexicographic Product of Two po-Groups has the Riesz Decomposition Property

We study conditions when a certain type of the Riesz Decomposition Property (RDP for short) holds in the lexicographic product of two po-groups. Defining two important properties of po-groups, we extend known situations showing that the lexicographic product satisfies RDP or even RDP$_1$, a stronger type of RDP. We recall that a very strong type of RDP, RDP$_2$, entails that the group is lattice ordered. RDP's of the lexicographic products are important for the study of lexicographic pseudo effect algebras, or perfect types of pseudo MV-algebras and pseudo effect algebras, where infinitesimal elements play an important role both for algebras as well as for the first order logic of valid but not provable formulas.

math.RA↗