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In this article, following [A.~Daneshgar, M.~Hejrati, M.~Madani, {\it On cylindrical graph construction and its applications}, EJC, 23(1) p1.29, 45, 2016] we study the spectra of symmetric cylindrical constructs, generalizing some…

Combinatorics · Mathematics 2016-10-11 Amir Daneshgar , Ali Taherkhani

We explore algebraic and spectral properties of weighted graphs containing twin vertices that are useful in quantum state transfer. We extend the notion of adjacency strong cospectrality to arbitrary Hermitian matrices, with focus on the…

Combinatorics · Mathematics 2023-12-29 Hermie Monterde

The spectral density of random graphs with topological constraints is analysed using the replica method. We consider graph ensembles featuring generalised degree-degree correlations, as well as those with a community structure. In each case…

Disordered Systems and Neural Networks · Physics 2011-04-08 Tim Rogers , Conrad Pérez Vicente , Koujin Takeda , Isaac Pérez Castillo

We introduce a graph renormalization procedure based on the coarse-grained Laplacian, which generates reduced-complexity representations for characteristic scales identified through the spectral gap. This method retains both diffusion…

Statistical Mechanics · Physics 2024-11-20 M. Schmidt , F. Caccioli , T. Aste

Connection graphs (CGs) extend traditional graph models by coupling network topology with orthogonal transformations, enabling the representation of global geometric consistency. They play a key role in applications such as synchronization,…

Machine Learning · Computer Science 2025-10-14 Leonardo Di Nino , Gabriele D'Acunto , Sergio Barbarossa , Paolo Di Lorenzo

Quantum graphs have attracted attention from mathematicians for some time. A quantum graph is defined by having a Laplacian on each edge of a metric graph and imposing boundary conditions at the vertices to get an eigenvalue problem. A…

Spectral Theory · Mathematics 2022-07-26 Mats-Erik Pistol , Pavel Kurasov

In this paper, we will explicitly construct cofree coalgebras, by first constructing cofree precoalgebras (namely those not necessarily coassociative or counital). Our approach does not impose any condition to the coefficient ring, which…

Rings and Algebras · Mathematics 2021-07-05 Yuki Goto

In this paper, we introduce a generalization of corona of graphs. This construction generalizes the generalized corona of graphs (consequently, the corona of graphs), the cluster of graphs, the corona-vertex subdivision graph of graphs and…

Combinatorics · Mathematics 2020-08-13 R. Rajkumar , M. Gayathri

In this work, we develop a spectral theory for hypergraph limits. We prove the convergence of the spectra of adjacency and Laplacian matrices for hypergraph sequences converging in the $1$-cut metric. On the other hand, we give examples of…

Combinatorics · Mathematics 2025-11-06 Ágnes Backhausz , Christian Kuehn , Sjoerd van der Niet , Giulio Zucal

We construct orbifolds with quasitoric boundary and show that they have stable almost complex structure. We show that a quasitoric orbifold is complex cobordant to finite disjoint copies of complex orbifold projective spaces. Finally some…

Algebraic Topology · Mathematics 2016-02-01 Soumen Sarkar

The "Perpendicular Bisectors Construction" is a natural way to seek a replacement for the circumcenter of a noncyclic quadrilateral in the plane. In this paper, we generalize this iterative construction to a construction on polytopes with…

Metric Geometry · Mathematics 2012-03-30 Emmanuel Tsukerman

By natural way the hierarchy structure is introduced on directed graphs with weighted adjacencies. Embedded system of algebras of subsets of the set of vertices of such digraph and it's consolidations, which vertices are the elementary sets…

Combinatorics · Mathematics 2007-05-23 V. A. Buslov

In this paper, we extend our earlier proposal of corona product of signed graphs into generalized corona product of signed graphs inspired by the generalized corona product of unsigned graphs. Then we study structural balance and spectral…

Combinatorics · Mathematics 2023-10-13 Amrik Singh , Ravi Srivastava , Bibhas Adhikari , Sandeep Kumar Yadav

We construct an additive category where objects are embedded graphs in the 3-sphere and morphisms are geometric correspondences given by 3-manifolds realized in different ways as branched covers of the 3-sphere, up to branched cover…

Mathematical Physics · Physics 2009-11-13 Matilde Marcolli , Ahmad Zainy al-Yasry

We introduce a zeta function of digraphs that determines, and is determined by, the spectra of all linear combinations of the adjacency matrix, its transpose, the out-degree matrix, and the in-degree matrix. In particular, zeta-equivalence…

Spectral Theory · Mathematics 2015-05-15 Peter Herbrich

We introduce a new numerically stable method for constructing superoscillatory wave forms inan arbitrary number of dimensions. The method allows the construction of superoscillatory square-integrable functions that match any desired smooth…

Optics · Physics 2020-04-08 Barbara Šoda , Achim Kempf

We present a construction of Neumaier graphs with nexus 1, which generalises two known constructions of Neumaier graphs. We also use W. Wang, L. Qiu, and Y. Hu switching to show that we construct cospectral Neumaier graphs. Finally, we show…

Combinatorics · Mathematics 2023-02-14 Rhys J. Evans , Sergey Goryainov , Elena V. Konstantinova , Alexander D. Mednykh

Networks with a prescribed power-law scaling in the spectrum of the graph Laplacian can be generated by evolutionary optimization. The Laplacian spectrum encodes the dynamical behavior of many important processes. Here, the networks are…

Physics and Society · Physics 2015-08-28 Steffen Karalus , Joachim Krug

We prove two results on convex subsets of Euclidean spaces invariant under an orthogonal group action. First, we show that invariant spectrahedra admit an equivariant spectrahedral description, i.e., can be described by an equivariant…

Algebraic Geometry · Mathematics 2025-11-05 Renato G. Bettiol , Mario Kummer , Ricardo A. E. Mendes

The monography examines the problem of constructing a group of automorphisms of a graph. A graph automorphism is a mapping of a set of vertices onto itself that preserves adjacency. The set of such automorphisms forms a vertex group of a…

History and Overview · Mathematics 2024-07-18 Sergey Kurapov , Maxim Davidovsky