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We define the Ricci curvature on simplicial complexes by modifying the definition of the Ricci curvature on graphs, and we prove the upper and lower bounds of the Ricci curvature. These properties are generalizations of previous studies.…

Spectral Theory · Mathematics 2022-06-06 Taiki Yamada

In this paper has been proved the pluripolarity of graphs of algebroid functions

Complex Variables · Mathematics 2010-05-10 Zafar Ibragimov

New criteria for which Cayley graphs of cyclic groups of any order can be completely determined--up to isomorphism--by the eigenvalues of their adjacency matrices is presented. Secondly, a new construction for pairs of nonisomorphic Cayley…

Combinatorics · Mathematics 2009-04-14 Julia Brown

In this paper, we continue the classification work done in the first paper of the same name. With careful modifications of our previous approach, we are able to deduce (with two notable exceptions) which members of the previously introduced…

Group Theory · Mathematics 2021-08-20 Sara DeGroot , Jacob Laubacher , Mark Medwid

Graphs derived from groups are a widely studied class of graphs, motivated by their highly symmetric structure. In particular, G-graphs offer an easy and interesting alternative construction of semi-symmetric graphs. After recalling the…

Combinatorics · Mathematics 2016-11-25 David Ellison , Ruxandra Marinescu-Ghemeci , Cerasela Tanasescu

A short proof of the linear nested Artin approximation property of the algebraic power series rings is given here.

Commutative Algebra · Mathematics 2016-01-28 Dorin Popescu

We give a brief survey of some known results on intrinsically linked or knotted graphs.

Geometric Topology · Mathematics 2020-06-15 Ramin Naimi

A version of Dehn's algorithm for simple diagrams on a once punctured surface representing simple diagrams on a closed surface is presented

Geometric Topology · Mathematics 2015-02-13 Charles Frohman , Joanna Kania-Bartoszynska

A broader definition of generalized truncations of graphs is introduced followed by an exploration of some standard concepts and parameters with regard to generalized truncations.

Combinatorics · Mathematics 2020-07-10 Brian Alspach , Joshua B. Connor

We state and prove some counting formulas relating to cliques in the distant graphs of projective lines over finite rings. As a preliminary to this, we prove a decomposition theorem for the graphs in terms of the direct-product…

Combinatorics · Mathematics 2016-12-26 Tim Silverman

We show NP-completeness for the recognition problem of 2-line-bend graphs.

Computational Complexity · Computer Science 2015-10-05 Martin Pergel

Let $N_g^k$ be a nonorientable surface of genus \ $g\geq 5$ \ with \ $k$-punctures. In this note, we will give an algebraic characterization of a Dehn twist about a simple closed curve on $N_g^k$. Along the way, we will fill some little…

Geometric Topology · Mathematics 2016-03-15 Ferihe Atalan

We prove new lower bounds on the crossing number of a complete graphs assuming that it is drawn in such a way that it contains a Hamiltonian cycle with no crossings.

Combinatorics · Mathematics 2013-09-13 Daniel M. Kane

We survey some of the known results on eigenvalues of Cayley graphs and their applications, together with related results on eigenvalues of Cayley digraphs and generalizations of Cayley graphs.

Combinatorics · Mathematics 2022-04-25 Xiaogang Liu , Sanming Zhou

In this short note we give a characterization of ZM-groups that uses the functions defined and studied in [3,4]. This leads to a proof of Conjecture 6 in [4].

Group Theory · Mathematics 2017-04-12 Marius Tărnăuceanu

It is known that isomorphisms of graph Jacobians induce cyclic bijections on the associated graphs. We characterize when such cyclic bijections can be strengthened to graph isomorphisms, in terms of an easily computed divisor. The result…

Combinatorics · Mathematics 2023-07-25 Sarah Griffith

We define a natural class of graphs by generalizing prior notions of visibility, allowing the representing regions and sightlines to be arbitrary. We consider mainly the case of compact connected representing regions, proving two results…

Combinatorics · Mathematics 2007-05-23 Mike Develin , Stephen Hartke , David Petrie Moulton

In this paper, we completely characterize the niche graphs of bipartite tournaments and find their interesting properties.

Combinatorics · Mathematics 2018-10-15 Soogang Eoh , Jihoon Choi , Suh-Ryung Kim , Miok Oh

In this note, we give short inductive proofs of two known results on $k$-extendible graphs based on a property proved in [Qinglin Yu, A note on $n$-extendable graphs. Journal of Graph Theory, 16:349-353, 1992].

Combinatorics · Mathematics 2021-10-08 Shenwei Huang , Yongtang Shi

A new shortest proof of Kotzig's Theorem about graphs with unique perfect matching is presented in this paper. It is well known that Kotzig's theorem is a consequence of Yeo's Theorem about edge-colored graph without alternating cycle. We…

Combinatorics · Mathematics 2014-02-06 Gleb Nenashev