Electronic Journal of Combinatorics  

Angela Carnevale, Elena Tielker

We show that the numerators of genus zeta function associated with local hereditary orders studied by Denert can be described in terms of the joint distribution of Euler-Mahonian statistics on multiset permutations defined by Han. We use this result to de... see more

Joshua Kiers

We give an inductive procedure for finding the extremal rays of the equivariant Littlewood-Richardson cone, which is closely related to the solution space to S. Friedland's majorized Hermitian eigenvalue problem. In so doing, we solve the "rational versio... see more

Shreya Ahirwar, Susanna Fishel, Parikshita Gya, Pamela E. Harris, Nguyen Pham, Andrés R. Vindas Meléndez, Dan Khanh Vo

David J. Grynkiewicz, Chao Liu

Melanie Tian, Enrique Treviño

Nathan Clisby, Andrew R. Conway, Anthony J. Guttmann, Yuma Inoue

Greg Malen, Fedor Manin, Érika Roldán

Megumi Harada, Martha Precup

In 2015, Brosnan and Chow, and independently Guay-Paquet, proved the Shareshian-Wachs conjecture, which links the Stanley-Stembridge conjecture in combinatorics to the geometry of Hessenberg varieties through Tymoczko's permutation group action on the coh... see more

T. Karthick , Jenny Kaufmann, Vaidy Sivaraman

Bryce McLaughlin, Mohamed Omar

Domagoj Bradac

The Po´sa-Seymour conjecture asserts that every graph on n vertices with minimum degree at least (1-1/(r +1))n contains the r-th power of a Hamilton cycle. Komlo´s, Sa´rko¨zy and Szemere´di famously proved the conjecture for large n. The notion of discrep... see more

Stoyan Dimitrov

Alessio D'Alì, Emanuele Delucchi, Mateusz Michalek

Symmetric edge polytopes are a class of lattice polytopes constructed from finite simple graphs. In the present paper we highlight their connections to the Kuramoto synchronization model in physics — where they are called adjacency polytopes — and to Kant... see more

Chaya Keller, Balázs Keszegh, Dömötör Pálvölgyi

Masahiro Hachimori, Akihiro Higashitani, Yumi Yamada

Oliver Cooley, Nicola Del Giudice, Mihyun Kang, Philipp Sprüssel

Logan Crew, Sophie Spirkl

Plethysm is a fundamental operation in symmetric function theory, derived directly from its connection with representation theory. However, it does not admit a simple combinatorial interpretation, and finding coefficients of Schur function plethysms is a ... see more

Lins Denaux

Lihong Yang, Sherry H.F. Yan

Zi-Xia Song

Daniel W. Cranston, Bernard Lidický, Xiaonan Liu, Abhinav Shantanam

Mingqing Zhai, Ruifang Liu, Jie Xue

Simone Costa, Stefano Della Fiore, M. A. Ollis, Sarah Z. Rovner-Frydman

Nicholas Proudfoot

We define a type B analogue of the category of finite sets with surjections, and we study the representation theory of this category. We show that the opposite category is quasi-Gröbner, which implies that submodules of finitely generated modules are agai... see more

Vincent E. Coll Jr., Nicholas W. Mayers, Nicholas Russoniello

We provide a combinatorial recipe for constructing all posets of height at most two for which the corresponding type-A Lie poset algebra is contact. In the case that such posets are connected, a discrete Morse theory argument establishes that the posets' ... see more

Narad Rampersad, Jeffrey Shallit

Certain famous combinatorial sequences, such as the Catalan numbers and the Motzkin numbers, when taken modulo a prime power, can be computed by finite automata. Many theorems about such sequences can therefore be proved using Walnut, which is an implemen... see more

Vladimir N. Potapov

Danila Cherkashin, Pavel Prozorov

Let GG be a simple graph with nn vertices and ±1\pm 1-weights on edges. Suppose that for every edge ee the sum of edges adjacent to ee (including ee itself) is positive. Then the sum of weights over edges of GG is at least -n225-\frac{n^2}{25}. Also we pr... see more

Shoni Gilboa, Roman Glebov, Dan Hefetz, Nati Linial, Avraham Morgenstern

AJ Bu

Bogdan Chornomaz

We give a characterization of shattering-extremal set systems in terms of forbidden projections, in the spirit of Dietrich's characterization of antimatroids. Apart from that, we prove several metric and topological properties of such systems, which, howe... see more

Sean English, Tomáš Masarík, Grace McCourt, Erin Meger, Michael S. Ross, Sam Spiro

Peter Bradshaw, Brandon Hanson, Misha Rudnev

Benjamin Przybocki

We study words that barely avoid repetitions, for several senses of "barely". A squarefree (respectively, overlap-free, cubefree) word is irreducible if removing any one of its interior letters creates a square (respectively, overlap, cube). A squarefree ... see more

Anton Bernshteyn, Eugene Lee