A lot of combinatorial objects have algebra and coalgebra structures and posets are important combinatorial objects. In this paper, we construct algebra and coalgebra structures on the vector space spanned by posets. ...A lot of combinatorial objects have algebra and coalgebra structures and posets are important combinatorial objects. In this paper, we construct algebra and coalgebra structures on the vector space spanned by posets. Firstly, by associativity and the unitary property, we prove that the vector space with the conjunction product is a graded algebra. Then by the definition of free algebra, we prove that the algebra is free. Finally, by the coassociativity and the counitary property, we prove that the vector space with the unshuffle coproduct is a graded coalgebra.展开更多
Triangulated categories coming from cyclic posets were originally introduced by the authors in a previous paper as a generalization of the constructions of various triangulated categories with cluster structures.We gi...Triangulated categories coming from cyclic posets were originally introduced by the authors in a previous paper as a generalization of the constructions of various triangulated categories with cluster structures.We give an overview, and then analyze "triangulation clusters" which are those corresponding to topological triangulations of the 2-disk. Locally finite nontriangulation clusters give topological triangulations of the "cactus space" associated to the "cactus cyclic poset".展开更多
In the present paper we investigate prinjective Ringel-Hall algebras, for prinjective modules over incidence algebras of posers of finite prinjective type. Results we obtain are analogous to these, given by C. M. Ring...In the present paper we investigate prinjective Ringel-Hall algebras, for prinjective modules over incidence algebras of posers of finite prinjective type. Results we obtain are analogous to these, given by C. M. Ringel, for representations of Dynkin quivers. In particular we give a description of prinjective Ringel-Hall algebras by generators and relations.展开更多
Let F denote the folded (2D + 1)-cube with vertex set X and diameter D ≥ 3. Fix x∈ X. We first define a partial order ≤ on X as follows. For y,z ∈ X let y ≤ z whenever (x,y)+ (y,z) =- (x, z). Let R ...Let F denote the folded (2D + 1)-cube with vertex set X and diameter D ≥ 3. Fix x∈ X. We first define a partial order ≤ on X as follows. For y,z ∈ X let y ≤ z whenever (x,y)+ (y,z) =- (x, z). Let R (resp. L) denote the raising matrix (resp. lowering matrix) of P. Next we show that there exists a certain linear dependency among RL2, LRL, L2R and L for each given Q-polynomial structure of F. Finally, we determine whether the above linear dependency structure gives this poser a uniform structure or strongly uniform structure.展开更多
In this paper, the definitions of the most common and elementary mappings between matroids are extended to antimatroids first. Then the poset theory is used to find out the fiats of an antimatroid and obtain all of st...In this paper, the definitions of the most common and elementary mappings between matroids are extended to antimatroids first. Then the poset theory is used to find out the fiats of an antimatroid and obtain all of strong maps for a given antimatroid. Besides, the poset theory is also used to deal with the relationships among the mappings between antimatroids. All the discussion is connected with poset theory. This claims that poset theory is an important tool for the study of antimatroid theory.展开更多
We assume that M is a phase space and H an Hilbert space yielded by a quantization scheme. In this paper we consider the set of all “experimental propositions” of M and we look for a model of quantum logic in relati...We assume that M is a phase space and H an Hilbert space yielded by a quantization scheme. In this paper we consider the set of all “experimental propositions” of M and we look for a model of quantum logic in relation to the quantization of the base manifold M. In particular we give a new interpretation about previous results of the author in order to build an “asymptotics quantum probability space” for the Hilbert lattice L(H).展开更多
In 1986, G.X. Viennot introduced the theory of heaps of pieces as a visualization of Cartier and Foata’s “partially commutative monoids”. These are essentially labeled posets satisfying a few additional properties,...In 1986, G.X. Viennot introduced the theory of heaps of pieces as a visualization of Cartier and Foata’s “partially commutative monoids”. These are essentially labeled posets satisfying a few additional properties, and one natural setting where they arise is as models of reduced words in Coxeter groups. In this paper, we introduce a cyclic version of a heap, which loosely speaking, can be thought of as taking a heap and wrapping it into a cylinder. We call this object a toric heap, because we formalize it as a labeled toric poset, which is a cyclic version of an ordinary poset. Defining the category of toric heaps leads to the notion of certain morphisms such as toric extensions. We study toric heaps in Coxeter theory, because a cyclic shift of a reduced word is simply a conjugate by an initial or terminal generator. As such, we formalize and study a framework that we call cyclic reducibility in Coxeter theory, which is closely related to conjugacy. We introduce what it means for elements to be torically reduced, which is a stronger condition than simply being cyclically reduced. Along the way, we encounter a new class of elements that we call torically fully commutative (TFC), which are those that have a unique cyclic commutativity class, and comprise a strictly bigger class than the cyclically fully commutative (CFC) elements. We prove several cyclic analogues of results on fully commutative (FC) elements due to Stembridge. We conclude with how this framework fits into recent work in Coxeter groups, and we correct a minor flaw in a few recently published theorems.展开更多
In this work, join and meet algebraic structure which exists in non-near-linear finite geometry are discussed. Lines in non-near-linear finite geometry ?were expressed as products of lines in near-linear finite geomet...In this work, join and meet algebraic structure which exists in non-near-linear finite geometry are discussed. Lines in non-near-linear finite geometry ?were expressed as products of lines in near-linear finite geometry ?(where?p?is a prime). An existence of lattice between any pair of near-linear finite geometry ?of ?is confirmed. For q|d, a one-to-one correspondence between the set of subgeometry ?of ?and finite geometry ?from the subsets of the set {D(d)}?of divisors of d?(where each divisor represents a finite geometry) and set of subsystems {∏(q)}?(with variables in Zq) of a finite quantum system ∏(d)?with variables in Zd?and a finite system from the subsets of the set of divisors of d?is established.展开更多
In this paper,we focus on p-sober spaces and prove that(1)the To space X is p-sober if and only if the Smyth power space of X is p-sober;(2)the space X has a p-sober dcpo model if and only if X is T_(1)and p-sober;(3)...In this paper,we focus on p-sober spaces and prove that(1)the To space X is p-sober if and only if the Smyth power space of X is p-sober;(2)the space X has a p-sober dcpo model if and only if X is T_(1)and p-sober;(3)every non-p-sober T_(0)space does not have a p-sobrification;(4)the T_(0)space X is sober if and only if X is p-sober and PD.展开更多
Let G be a group,and let →/ΓC(G) be a digraph whose vertices are the nontrivial conjugacy classes of G and there is an arc from a vertex C to a vertex C' if and only if C≠C' and(C)■(C').In this paper,w...Let G be a group,and let →/ΓC(G) be a digraph whose vertices are the nontrivial conjugacy classes of G and there is an arc from a vertex C to a vertex C' if and only if C≠C' and(C)■(C').In this paper,we characterize finite groups G whose associated digraphs →/ΓC(G) are oriented trees.展开更多
In this short note we prove that the finite non-abelian simple groups PSL(2,q),where g=5,7,are determincd by their posets of classes of isomorphic subgroups.Several interesting open problems are also formulated.
An excellent introduction to the topic of poset matroids is due to Barnabei, Nicoletti and Pezzoli. In this paper, we investigate the rank axioms for poset matroids; thereby we can characterize poset matroids in a “g...An excellent introduction to the topic of poset matroids is due to Barnabei, Nicoletti and Pezzoli. In this paper, we investigate the rank axioms for poset matroids; thereby we can characterize poset matroids in a “global” version and a “pseudo-global” version. Some corresponding properties of combinatorial schemes are also obtained.展开更多
Let n and k be arbitrary positive integers, p a prime number and L(kn)(p) the subgroup lattice of the Abelian p-group ( /pk )n. Then there is a positive integer N( n, k) such that when p 】 N( n, k), L(kn)(p) has the ...Let n and k be arbitrary positive integers, p a prime number and L(kn)(p) the subgroup lattice of the Abelian p-group ( /pk )n. Then there is a positive integer N( n, k) such that when p 】 N( n, k), L(kn)(p) has the strong Sperner property.展开更多
In the present paper we describe a specialization of prinjective Ringel-Hall algebra to 1, for prinjective modules over incidence algebras of posets of finite prinjective type, by generators and relations. This gives ...In the present paper we describe a specialization of prinjective Ringel-Hall algebra to 1, for prinjective modules over incidence algebras of posets of finite prinjective type, by generators and relations. This gives us a generalisation of Serre relations for semisimple Lie algebras. Connections of prinjective Ringel-Hall algebras with classical Lie algebras are also discussed.展开更多
In this paper, some properties of order topology and bi-Scott topology on a poset are obtained. Order-convergence in posets is further studied. Especially, a sufficient and necessary condition for order-convergence to...In this paper, some properties of order topology and bi-Scott topology on a poset are obtained. Order-convergence in posets is further studied. Especially, a sufficient and necessary condition for order-convergence to be topological is given for some kind of posers.展开更多
In this paper, we introduce some new definitions such as the U*L* condition to describe the zero-divisor graph G = F(P) of a poser P, and give a new and quick proof to a main result in [2, 4]. By deleting a typica...In this paper, we introduce some new definitions such as the U*L* condition to describe the zero-divisor graph G = F(P) of a poser P, and give a new and quick proof to a main result in [2, 4]. By deleting a typical vertex with least degree, we provide an algorithm for finding a maximum clique of a finite graph G. We study some properties of the zero-divisor graphs of posets concerning diameters and girths. We also provide stratified presentations of posets.展开更多
文摘A lot of combinatorial objects have algebra and coalgebra structures and posets are important combinatorial objects. In this paper, we construct algebra and coalgebra structures on the vector space spanned by posets. Firstly, by associativity and the unitary property, we prove that the vector space with the conjunction product is a graded algebra. Then by the definition of free algebra, we prove that the algebra is free. Finally, by the coassociativity and the counitary property, we prove that the vector space with the unshuffle coproduct is a graded coalgebra.
文摘Triangulated categories coming from cyclic posets were originally introduced by the authors in a previous paper as a generalization of the constructions of various triangulated categories with cluster structures.We give an overview, and then analyze "triangulation clusters" which are those corresponding to topological triangulations of the 2-disk. Locally finite nontriangulation clusters give topological triangulations of the "cactus space" associated to the "cactus cyclic poset".
文摘In the present paper we investigate prinjective Ringel-Hall algebras, for prinjective modules over incidence algebras of posers of finite prinjective type. Results we obtain are analogous to these, given by C. M. Ringel, for representations of Dynkin quivers. In particular we give a description of prinjective Ringel-Hall algebras by generators and relations.
基金Supported by the Natural Science Foundation of China(No.11471097)the Innovative Fund Project of Hebei Province(sj.2017084)
文摘Let F denote the folded (2D + 1)-cube with vertex set X and diameter D ≥ 3. Fix x∈ X. We first define a partial order ≤ on X as follows. For y,z ∈ X let y ≤ z whenever (x,y)+ (y,z) =- (x, z). Let R (resp. L) denote the raising matrix (resp. lowering matrix) of P. Next we show that there exists a certain linear dependency among RL2, LRL, L2R and L for each given Q-polynomial structure of F. Finally, we determine whether the above linear dependency structure gives this poser a uniform structure or strongly uniform structure.
文摘In this paper, the definitions of the most common and elementary mappings between matroids are extended to antimatroids first. Then the poset theory is used to find out the fiats of an antimatroid and obtain all of strong maps for a given antimatroid. Besides, the poset theory is also used to deal with the relationships among the mappings between antimatroids. All the discussion is connected with poset theory. This claims that poset theory is an important tool for the study of antimatroid theory.
文摘We assume that M is a phase space and H an Hilbert space yielded by a quantization scheme. In this paper we consider the set of all “experimental propositions” of M and we look for a model of quantum logic in relation to the quantization of the base manifold M. In particular we give a new interpretation about previous results of the author in order to build an “asymptotics quantum probability space” for the Hilbert lattice L(H).
文摘In 1986, G.X. Viennot introduced the theory of heaps of pieces as a visualization of Cartier and Foata’s “partially commutative monoids”. These are essentially labeled posets satisfying a few additional properties, and one natural setting where they arise is as models of reduced words in Coxeter groups. In this paper, we introduce a cyclic version of a heap, which loosely speaking, can be thought of as taking a heap and wrapping it into a cylinder. We call this object a toric heap, because we formalize it as a labeled toric poset, which is a cyclic version of an ordinary poset. Defining the category of toric heaps leads to the notion of certain morphisms such as toric extensions. We study toric heaps in Coxeter theory, because a cyclic shift of a reduced word is simply a conjugate by an initial or terminal generator. As such, we formalize and study a framework that we call cyclic reducibility in Coxeter theory, which is closely related to conjugacy. We introduce what it means for elements to be torically reduced, which is a stronger condition than simply being cyclically reduced. Along the way, we encounter a new class of elements that we call torically fully commutative (TFC), which are those that have a unique cyclic commutativity class, and comprise a strictly bigger class than the cyclically fully commutative (CFC) elements. We prove several cyclic analogues of results on fully commutative (FC) elements due to Stembridge. We conclude with how this framework fits into recent work in Coxeter groups, and we correct a minor flaw in a few recently published theorems.
文摘In this work, join and meet algebraic structure which exists in non-near-linear finite geometry are discussed. Lines in non-near-linear finite geometry ?were expressed as products of lines in near-linear finite geometry ?(where?p?is a prime). An existence of lattice between any pair of near-linear finite geometry ?of ?is confirmed. For q|d, a one-to-one correspondence between the set of subgeometry ?of ?and finite geometry ?from the subsets of the set {D(d)}?of divisors of d?(where each divisor represents a finite geometry) and set of subsystems {∏(q)}?(with variables in Zq) of a finite quantum system ∏(d)?with variables in Zd?and a finite system from the subsets of the set of divisors of d?is established.
基金Supported by the National Natural Science Foundation of China(Grant No.11531009)。
文摘In this paper,we focus on p-sober spaces and prove that(1)the To space X is p-sober if and only if the Smyth power space of X is p-sober;(2)the space X has a p-sober dcpo model if and only if X is T_(1)and p-sober;(3)every non-p-sober T_(0)space does not have a p-sobrification;(4)the T_(0)space X is sober if and only if X is p-sober and PD.
文摘Let G be a group,and let →/ΓC(G) be a digraph whose vertices are the nontrivial conjugacy classes of G and there is an arc from a vertex C to a vertex C' if and only if C≠C' and(C)■(C').In this paper,we characterize finite groups G whose associated digraphs →/ΓC(G) are oriented trees.
文摘In this short note we prove that the finite non-abelian simple groups PSL(2,q),where g=5,7,are determincd by their posets of classes of isomorphic subgroups.Several interesting open problems are also formulated.
基金Supported by the National Natural Science Foundation of China (Granted No.103710438)Education Ministry of China (Granted No.02139)
文摘An excellent introduction to the topic of poset matroids is due to Barnabei, Nicoletti and Pezzoli. In this paper, we investigate the rank axioms for poset matroids; thereby we can characterize poset matroids in a “global” version and a “pseudo-global” version. Some corresponding properties of combinatorial schemes are also obtained.
文摘Let n and k be arbitrary positive integers, p a prime number and L(kn)(p) the subgroup lattice of the Abelian p-group ( /pk )n. Then there is a positive integer N( n, k) such that when p 】 N( n, k), L(kn)(p) has the strong Sperner property.
文摘In the present paper we describe a specialization of prinjective Ringel-Hall algebra to 1, for prinjective modules over incidence algebras of posets of finite prinjective type, by generators and relations. This gives us a generalisation of Serre relations for semisimple Lie algebras. Connections of prinjective Ringel-Hall algebras with classical Lie algebras are also discussed.
基金Supported by National Natural Science Foundation of China (Grant Nos. 10871121, 11001158)
文摘In this paper, some properties of order topology and bi-Scott topology on a poset are obtained. Order-convergence in posets is further studied. Especially, a sufficient and necessary condition for order-convergence to be topological is given for some kind of posers.
基金Supported by the National Natural Science Foundation of China (11271250).Acknowledgements. The authors express their sincere thanks to the referees for the careful reading and suggestions which improved the exposition of the paper.
文摘In this paper, we introduce some new definitions such as the U*L* condition to describe the zero-divisor graph G = F(P) of a poser P, and give a new and quick proof to a main result in [2, 4]. By deleting a typical vertex with least degree, we provide an algorithm for finding a maximum clique of a finite graph G. We study some properties of the zero-divisor graphs of posets concerning diameters and girths. We also provide stratified presentations of posets.