• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-07-27
Akansha Arora, Samrith Ram, Ayineedi Venkateswarlu

We consider some combinatorial problems on matrix polynomials over finite fields. Using results from control theory, we give a proof of a result of Lieb, Jordan and Helmke on the number of linear unimodular matrix polynomials over a finite field. As an application of our results, we give a new proof of a theorem of Chen and Tseng which answers a question of Niederreiter on splitting subspaces. We use

更新日期：2020-07-27
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-22
Jing Huang, Shuchao Li

A graph is said to be integral (resp. distance integral) if all the eigenvalues of its adjacency matrix (resp. distance matrix) are integers. Let H be a finite abelian group, and let $${\mathscr {H}}=\langle H,b\,|\,b^2=1,bhb=h^{-1},h\in H\rangle$$ be the generalized dihedral group of H. The contribution of this paper is threefold. Firstly, based on the representation theory of finite groups, we obtain

更新日期：2020-06-22
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-15
Paul Barry, Aoife Hennessy, Nikolaos Pantelidis

We present properties of the group structure of Riordan arrays. We examine similar properties among known Riordan subgroups, and from this, we define H[r, s, p], a family of Riordan arrays. We generalize conditions for involutions, and pseudo-involutions of H[r, s, p], and we present stabilizers of this family. We find abelian subgroups as intersections of Riordan subgroups and show some alternative

更新日期：2020-06-15
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-13
Marston D. E. Conder, Ademir Hujdurović, Klavdija Kutnar, Dragan Marušič

Properties of symmetric cubic graphs are described via their rigid cells, which are maximal connected subgraphs fixed pointwise by some involutory automorphism of the graph. This paper completes the description of rigid cells and the corresponding involutions for each of the 17 ‘action types’ of symmetric cubic graphs.

更新日期：2020-06-13
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-13
Andrea Caggegi, Giovanni Falcone, Marco Pavone

We show that any affine block design $$\mathcal{D}=(\mathcal{P},\mathcal{B})$$ is a subset of a suitable commutative group $${\mathfrak {G}}_\mathcal{D},$$ with the property that a k-subset of $$\mathcal{P}$$ is a block of $$\mathcal{D}$$ if and only if its k elements sum up to zero. As a consequence, the group of automorphisms of any affine design $$\mathcal{D}$$ is the group of automorphisms of $${\mathfrak 更新日期：2020-06-13 • J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-13 Matthew Dyer, Weijia Wang This paper investigates the question of uniqueness of the reduced oriented matroid structure arising from root systems of a Coxeter system in real vector spaces. We settle the question for finite Coxeter systems, irreducible affine Weyl groups and all rank three Coxeter systems. In these cases, the oriented matroid structure is unique unless W is of type \({\widetilde{A}}_n, n\ge 3$$, in which case

更新日期：2020-06-13
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-13
Tien Chih, Laura Scull

We show that the category of graphs has the structure of a 2-category with homotopy as the 2-cells. We then develop an explicit description of homotopies for finite graphs, in terms of what we call ‘spider moves.’ We then create a category by modding out by the 2-cells of our 2-category and use the spider moves to show that for finite graphs, this category is a homotopy category in the sense that it

更新日期：2020-06-13
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-12
Aba Mbirika, Julianna Tymoczko

A sequence of $$S_n$$-representations $$\{V_n\}$$ is said to be uniformly representation stable if the decomposition of $$V_n = \bigoplus _{\mu } c_{\mu ,n} V(\mu )_n$$ into irreducible representations is independent of n for each $$\mu$$—that is, the multiplicities $$c_{\mu ,n}$$ are eventually independent of n for each $$\mu$$. Church–Ellenberg–Farb proved that the cohomology of flag varieties

更新日期：2020-06-12
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-10
Seung Jin Lee

LLT polynomials are q-analogs of products of Schur functions that are known to be Schur positive by Grojnowski and Haiman. However, there is no known combinatorial formula for the coefficients in the Schur expansion. Finding such a formula also provides Schur positivity of Macdonald polynomials. On the other hand, Haiman and Haglund conjectured that LLT polynomials for skew partitions lying on k adjacent

更新日期：2020-06-10
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-10
Dancheng Lu

Let I be a two-dimensional squarefree monomial ideal of a polynomial ring S. We evaluate the geometric regularity, $$a_i$$-invariants of $$S/I^n$$ for $$i\ge 2$$. It turns out that they are all linear functions in n from $$n=2$$. Also, it is shown that $$\text{ g-reg }(S/I^n)={\text {reg}}(S/I^{(n)})$$ for all $$n\ge 1$$.

更新日期：2020-06-10
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-06-09
Soojin Cho, JiSun Huh, Sun-Young Nam

We investigate chromatic symmetric functions in relation to the algebra $$\varGamma$$ of symmetric functions generated by Schur Q-functions. We construct natural bases of $$\varGamma$$ in terms of chromatic symmetric functions. We also consider the p-positivity of skew Schur Q-functions and find a class of p-positive ribbon Schur Q-functions, making a conjecture that they are only p-positive Schur

更新日期：2020-06-09
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-05-25
Daniel Corey

We introduce the notion of tropical curves of hyperelliptic type. These are tropical curves whose Jacobian is isomorphic to that of a hyperelliptic tropical curve, as polarized tropical abelian varieties. We show that this property depends only on the underlying graph of a tropical curve and is preserved when passing to genus $$\ge 2$$ connected minors. The main result is an forbidden minors characterization

更新日期：2020-05-25
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-23
Hanmeng Zhan

We introduce a new type of discrete quantum walks, called vertex-face walks, based on orientable embeddings. We first establish a spectral correspondence between the transition matrix U and the vertex-face incidence structure. Using the incidence graph, we derive a formula for the principal logarithm of $$U^2$$, and find conditions for its underlying digraph to be an oriented graph. In particular,

更新日期：2020-04-23
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-20
Li Cui, Jin-Xin Zhou, Mohsen Ghasemi, Ali Asghar Talebi, Rezvan Varmazyar

A Cayley graph $$\mathrm{Cay}(G, S)$$ on a group G is said to be normal if the right regular representation R(G) of G is normal in the full automorphism group of $$\mathrm{Cay}(G, S)$$. In this paper, a complete classification is given of tetravalent non-normal Cayley graphs of order $$2p^2$$ for each prime p.

更新日期：2020-04-20
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-18
C. J. Jones, L.-K. Lauderdale, Sarah E. Lubow, Carlie J. Triplitt

For a positive integer m, let $${\mathbb {Z}}_m$$ denote the cyclic group of order m. In this article, we discuss the orders of vertex-minimal planar graphs with prescribed automorphism group $${\mathbb {Z}}_m$$. Previously, Marušič investigated the case when m is odd, and Archer et al. considered the case when m is a power of 2. When m even and not a power of 2, Marušič conjectured the order of a

更新日期：2020-04-18
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-15
Jung-Chao Ban, Chih-Hung Chang, Yu-Hsiung Huang

Let $$G=\left\langle S|R_{A}\right\rangle$$ be a semigroup with generating set S and equivalences $$R_{A}$$ among S determined by a matrix A. This paper investigates the complexity of G-shift spaces by yielding the Petersen–Salama entropies [defined in Petersen and Salama (Theoret Comput Sci 743:64–71, 2018)]. After revealing the existence of Petersen–Salama entropy of G-shift of finite type (G-SFT)

更新日期：2020-04-15
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-13
Omar Tout

We generalize the concept of partial permutations of Ivanov and Kerov and introduce k-partial permutations. This allows us to show that the structure coefficients of the center of the wreath product $${\mathcal {S}}_k\wr {\mathcal {S}}_n$$ algebra are polynomials in n with nonnegative integer coefficients. We use a universal algebra $${\mathcal {I}}_\infty ^k$$, which projects on the center $$Z({\mathbb 更新日期：2020-04-13 • J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-10 Ralph Morrison Abstractly, tropical hyperelliptic curves are metric graphs that admit a two-to-one harmonic morphism to a tree. They also appear as embedded tropical curves in the plane arising from triangulations of polygons with all interior lattice points collinear. We prove that hyperelliptic graphs can only arise from such polygons. Along the way, we will prove certain graphs do not embed tropically in the plane 更新日期：2020-04-10 • J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-09 Michal Sedlák, Alessandro Bisio Based on the work of Vershik (J Sov Math 59(5):1029–1040, 1992), we introduce two new combinatorial identities. We show how these identities can be used to prove a new hook-content identity. The main motivation for deriving this identity was a particular optimization problem in the field of quantum information processing. 更新日期：2020-04-09 • J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-06 Yunnan Li, Li Guo This paper studies the braidings of several Hopf algebras of rooted trees which have found broad applications. First by studying free braided dendriform algebras, we obtain the braiding of the Loday–Ronco Hopf algebra of planar binary rooted trees. We also give a variation of the braiding obtained by Foissy for the noncommutative Connes–Kreimer (a.k.a the Foissy–Holtkamp) Hopf algebra of planar rooted 更新日期：2020-04-06 • J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-06 Per Alexandersson We conjecture an explicit positive combinatorial formula for the expansion of unicellular LLT polynomials in the elementary symmetric basis. This is an analogue of the Shareshian–Wachs conjecture previously studied by Panova and the author in 2018. We show that the conjecture for unicellular LLT polynomials implies a similar formula for vertical-strip LLT polynomials. We prove positivity in the elementary 更新日期：2020-04-06 • J. Algebraic Comb. (IF 0.805) Pub Date : 2020-04-06 Paul-Henry Leemann, Mikael de la Salle We show that every finitely generated group G with an element of order at least \(\bigl (5{{\,\mathrm{rank}\,}}(G)\bigr )^{12}$$ admits a locally finite directed Cayley graph with automorphism group equal to G. If moreover G is not generalized dihedral, then the above Cayley directed graph does not have bigons. On the other hand, if G is neither generalized dicyclic nor abelian and has an element of

更新日期：2020-04-06
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-03-31
Tushar D. Parulekar, Sharad S. Sane

A Ryser design $${\mathcal {D}}$$ on v points is a collection of v proper subsets (called blocks) of a point-set with v points such that every two blocks intersect each other in $$\lambda$$ points (and $$\lambda < v$$ is a fixed number) and there are at least two block sizes. A design $${\mathcal {D}}$$ is called a symmetric design, if every point of $${\mathcal {D}}$$ has the same replication number

更新日期：2020-03-31
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-03-18
Connor Ahlbach

We introduce tableau stabilization, a new phenomenon and statistic on Young tableaux based on jeu de taquin. We investigate bounds for tableau stabilization, the shape of stabilized tableaux, and tableau stabilization as a permutation statistic. We apply tableau stabilization to construct the sufficiently large rectangular tableaux fixed by powers of promotion, which were counted by Brendon Rhoades

更新日期：2020-03-18
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-02-28
Josep Àlvarez Montaner, Fatemeh Sohrabi

We develop splitting techniques to study the Lyubeznik numbers of cover ideals of graphs which allow us to describe them for large families of graphs including forests, cycles, wheels and cactus graphs. More generally, we are able to compute all the Bass numbers and the shape of the injective resolution of local cohomology modules by considering the connected components of all the induced subgraphs

更新日期：2020-02-28
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-02-21
Y. S. Kwon, A. D. Mednykh, I. A. Mednykh

In the present paper, we investigate the complexity of infinite family of graphs $$H_n=H_n(G_1,\,G_2,\ldots ,G_m)$$ obtained as a circulant foliation over a graph H on m vertices with fibers $$G_1,\,G_2,\ldots ,G_m.$$ Each fiber $$G_i=C_n(s_{i,1},\,s_{i,2},\ldots ,s_{i,k_i})$$ of this foliation is the circulant graph on n vertices with jumps $$s_{i,1},\,s_{i,2},\ldots ,s_{i,k_i}.$$ This family includes

更新日期：2020-02-21
• J. Algebraic Comb. (IF 0.805) Pub Date : 2020-02-20
Behnam Khosravi, Behrooz Khosravi, Bahman Khosravi

In 1982, Babai and Godsil conjectured that almost all Cayley digraphs are digraphical regular representations. In 1998, Xu conjectured that almost all Cayley digraphs are normal [i.e., $$G_L$$ is a normal subgroup of the automorphism group of $$\text {Cay}(G,C)$$]. Finally, in 1994, Praeger and Mckay conjectured that almost all undirected vertex-transitive graphs are Cayley graphs of groups. In this

更新日期：2020-02-20
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-06-18
Geoffrey R. Grimmett, Zhongyang Li

We study the connective constants of weighted self-avoiding walks (SAWs) on infinite graphs and groups. The main focus is upon weighted SAWs on finitely generated, virtually indicable groups. Such groups possess so-called height functions, and this permits the study of SAWs with the special property of being bridges. The group structure is relevant in the interaction between the height function and

更新日期：2019-06-18
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-06-10
Yan-Quan Feng, István Kovács, Da-Wei Yang

A Cayley graph of a group H is a finite simple graph $$\Gamma$$ such that $$\mathrm{Aut}(\Gamma )$$ contains a subgroup isomorphic to H acting regularly on $$V(\Gamma ),$$ while a Haar graph of H is a finite simple bipartite graph $$\Sigma$$ such that $$\mathrm{Aut}(\Sigma )$$ contains a subgroup isomorphic to H acting semiregularly on $$V(\Sigma )$$ and the H-orbits are equal to the bipartite sets

更新日期：2019-06-10
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-06-06

In this article, we introduce the Laplacian matching polynomial of a graph. We prove some results concerning this new polynomial which can be viewed as analogue results on the classical matching polynomial.

更新日期：2019-06-06
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-06-04
Majid Arezoomand

A graph $$\varGamma$$ is called n-Cayley graph over a group G if $$\mathrm{Aut}(\varGamma )$$ has a semiregular subgroup isomorphic to G with n orbits (of equal size). In this paper, we give a decomposition of the Laplacian and signless Laplacian polynomials of n-Cayley graphs in terms of irreducible representations of G. Also, we construct several families of graphs with integral Laplacian and signless

更新日期：2019-06-04
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-06-04
Jarod Alper, Rowan Rowlands

We investigate the space of syzygies of the apolar ideals $${\text {det}}_n^\perp$$ and $${\mathrm{perm}}_n^\perp$$ of the determinant $${\text {det}}_n$$ and permanent $${\mathrm{perm}}_n$$ polynomials. Shafiei had proved that these ideals are generated by quadrics and provided a minimal generating set. Extending on her work, in characteristic distinct from two, we prove that the space of relations

更新日期：2019-06-04
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-06-04
Andrea Pasquali, Erik Thörnblad, Jakob Zimmermann

We investigate the existence of maximal collections of mutually noncrossing k-element subsets of $$\left\{ 1, \ldots , n \right\}$$ that are invariant under adding $$k\pmod n$$ to all indices. Our main result is that such a collection exists if and only if k is congruent to 0, 1 or $$-1$$ modulo $$n/{\text {GCD}}(k,n)$$. Moreover, we present some algebraic consequences of our result related to self-injective

更新日期：2019-06-04
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-06-03
Xiaojing Chen, Wenchang Chu

The duplicate form of the Carlitz inversions is employed to prove new identities for terminating balanced $$_4\phi _3$$-series. Their limiting series are deduced as consequences. The “dual formulae” are also derived by means of the polynomial argument.

更新日期：2019-06-03
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-25
Cécile Mammez

In this article, we study the Hopf algebra $$\mathcal {H}_{\tiny \textsc {D}}$$ of dissection diagrams introduced by Dupont in his thesis, more precisely we focus on its underlying coalgebra. We use the version with a parameter x in the base field. We conjecture it is cofree if $$x=1$$ or x is not a root of unity. If $$x=-1$$, then we know there is no cofreeness. Since $$\mathcal {H}_{\tiny \textsc 更新日期：2019-05-25 • J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-23 Ulrich Dempwolff In the predecessor to this paper Dempwolff (Comm Algebra 34(3):1077–1131, 2006), group-theoretic methods were used to solve automorphism and equivalence questions for (certain) ordinary bent functions, i.e., bent functions over \(\mathbb {F}_2$$. Here, we consider the same problems for p-ary bent functions, p an odd prime and solve these questions for functions analogous to those which appear in Dempwolff

更新日期：2019-05-23
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-22
Yan-Hong Bao, Yi-Zheng Fan, Yi Wang, Ming Zhu

Using the Poisson formula for resultants, and variants of the chip-firing game on graphs, we provide a combinatorial method for computing a class of resultants corresponding to the characteristic polynomials of the adjacency tensors of starlike hypergraphs including hyperpaths and hyperstars, which are given recursively and explicitly.

更新日期：2019-05-22
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-21
Fatemeh Mohammadi, Patricia Pascual-Ortigosa, Eduardo Sáenz-de-Cabezón, Henry P. Wynn

Polarization is a powerful technique in algebra which provides combinatorial tools to study algebraic invariants of monomial ideals. We study the reverse of this process, depolarization which leads to a family of ideals which share many common features with the original ideal. Given a squarefree monomial ideal, we describe a combinatorial method to obtain all its depolarizations, and we highlight their

更新日期：2019-05-21
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-20
Shilpa Gondhali

The topological $$K^{*}$$ ring is one of the important tools used for understanding the topology of a manifold. We settle a problem of computing the $$K^{*}$$ ring of complex projective Stiefel manifold using combinatorics. We calculate $$K^{*}$$ ring of the right generalized projective Stiefel manifold, denoted by $$P_{\ell }W_{n,k}$$ , which gives us description of complex $$K^{*}$$ ring of complex

更新日期：2019-05-20
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-20
Yi Zhang, Xing Gao

Parallel to operated algebras built on top of planar rooted trees via the grafting operator $$B^+$$, we introduce and study $$\vee$$-algebras and more generally $$\vee _\Omega$$-algebras based on planar binary trees. Involving an analogy of the Hochschild 1-cocycle condition, cocycle $$\vee _\Omega$$-bialgebras (resp. $$\vee _\Omega$$-Hopf algebras) are also introduced and their free objects are

更新日期：2019-05-20
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-18
Dean Crnković, Sanja Rukavina, Andrea Švob

We construct distance-regular graphs, including strongly regular graphs, admitting a transitive action of the Chevalley groups $$G_2(4)$$ and $$G_2(5)$$, the orthogonal group O(7, 3) and the Tits group $$T=$$$$^2F_4(2)'$$. Most of the constructed graphs have more than 1000 vertices, and the number of vertices goes up to 28431. Some of the obtained graphs are new.

更新日期：2019-05-18
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-05-18
Elisa Gorla, Relinde Jurrius, Hiram H. López, Alberto Ravagnani

This paper contributes to the study of rank-metric codes from an algebraic and combinatorial point of view. We introduce q-polymatroids, the q-analogue of polymatroids, and develop their basic properties. We associate a pair of q-polymatroids with a rank-metric code and show that several invariants and structural properties of the code, such as generalized weights, the property of being MRD or an optimal

更新日期：2019-05-18
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-04-09
František Marko

Let $$G=GL(m|n)$$ be the general linear supergroup over an algebraically closed field K of characteristic zero, and let $$G_{ev}=GL(m)\times GL(n)$$ be its even subsupergroup. The induced supermodule $$H^0_G(\lambda )$$, corresponding to a dominant weight $$\lambda$$ of G, can be represented as $$H^0_{G_{ev}}(\lambda )\otimes \Lambda (Y)$$, where $$Y=V_m^*\otimes V_n$$ is a tensor product of the dual

更新日期：2019-04-09
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-04-01
Pasquale Petrullo, Domenico Senato

We introduce the monoid of the admissible KF polynomials. These polynomials are invariant under uniform translation of partitions. Moreover, each Kostka–Foulkes polynomial turns out to be a linear combination of admissible KF polynomials with coefficients $$-1$$ or 1. Elementary manipulations of triangular matrices provide identities on Kostka–Foulkes polynomials which are not obvious a priori.

更新日期：2019-04-01
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-03-27

We introduce a weighted quasisymmetric enumerator function associated with generalized permutohedra. It refines the Billera, Jia and Reiner quasisymmetric function which also includes the Stanley chromatic symmetric function. Besides that, it carries information of face numbers of generalized permutohedra. We consider more systematically the cases of nestohedra and matroid base polytopes.

更新日期：2019-03-27
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-03-26
Ricardo Grande, István Kovács, Klavdija Kutnar, Aleksander Malnič, Luis Martínez, Dragan Marušič

We introduce a special kind of partial sum families, which we call equisizable partial sum families, that can be used to obtain directed strongly regular graphs admitting a semiregular group of automorphisms. We give a construction of an infinite family of equisizable partial sum families depending on two parameters that produce directed strongly regular graphs with new parameters. We also determine

更新日期：2019-03-26
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-03-26
Anna Maria Bigatti, Elisa Palezzato, Michele Torielli

In this article, we describe two new characterizations of freeness for hyperplane arrangements via the study of the generic initial ideal and of the sectional matrix of the Jacobian ideal of arrangements.

更新日期：2019-03-26
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-03-23
Mandira Mondal, Vijaylaxmi Trivedi

We prove that, analogous to the Hilbert–Kunz density function, (used for studying the Hilbert–Kunz multiplicity, the leading coefficient of the Hibert–Kunz function), there exists a $$\beta$$-density function $$g_{R, \mathbf{m}}:[0,\infty )\longrightarrow {\mathbb {R}}$$, where $$(R, \mathbf{m})$$ is the homogeneous coordinate ring associated with the toric pair (X, D), such that \begin{aligned}

更新日期：2019-03-23
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-02-02
Jie Du, Yanan Lin, Zhongguo Zhou

As a homomorphic image of the hyperalgebra $$U_{q,R}(m|n)$$ associated with the quantum linear supergroup $$U_{\varvec{\upsilon }}(\mathfrak {gl}_{m|n})$$, we first give a presentation for the q-Schur superalgebra $$S_{q,R}(m|n,r)$$ over a commutative ring R. We then develop a criterion for polynomial supermodules of $$U_{q,F}(m|n)$$ over a field F and use this to determine a classification of polynomial

更新日期：2019-02-02
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-01-31
Xiuyun Wang, Jihui Wang, Yan Liu

A graph is half-arc-transitive if its automorphism group acts transitively on its vertex set, edge set, but not arc set. Let p be a prime. It is known that there exist no tetravalent half-arc-transitive graphs of order p or 2p. Feng et al. (J Algebraic Combin 26:431–451, 2007) gave the classification of tetravalent half-arc-transitive graphs of order 4p. In this paper, a classification is given of

更新日期：2019-01-31
• J. Algebraic Comb. (IF 0.805) Pub Date : 2019-01-23
Michela Di Marca, Grzegorz Malara, Alessandro Oneto

In a recent paper, Cook et al. (Compos Math 154:2150–2194, 2018) used the splitting type of a line arrangement in the projective plane to study the number of conditions imposed by a general fat point of multiplicity j on the linear system of curves of degree $$j+1$$ passing through the configuration of points dual to the given arrangement. If the number of conditions is less than the expected, they

更新日期：2019-01-23
Contents have been reproduced by permission of the publishers.

down
wechat
bug