English
Related papers

Related papers: Spectral maps associated to semialgebraic branched…

200 papers

We present a parallelized bijective graph matching algorithm that leverages seeds and is designed to match very large graphs. Our algorithm combines spectral graph embedding with existing state-of-the-art seeded graph matching procedures.…

Spectrahedra are sets defined by linear matrix inequalities. Projections of spectrahedra are called semidefinitely representable sets. Both kinds of sets are of practical use in polynomial optimization, since they occur as feasible sets in…

Optimization and Control · Mathematics 2009-12-17 Tim Netzer

A family of graphs is called degenerate if it contains at least one bipartite graph. In this paper, we investigate the spectral extremal problems for a degenerate family of graphs $\mathcal{F}$. By employing covering and independent…

Combinatorics · Mathematics 2025-07-17 Jiadong Wu , Liying Kang , Zhenyu Ni

A graph is $1$-planar if it has a drawing in the plane such that each edge is crossed at most once by another edge. Moreover, if this drawing has the additional property that for each crossing of two edges the end vertices of these edges…

Combinatorics · Mathematics 2020-01-27 Igor Fabrici , Jochen Harant , Tomáš Madaras , Samuel Mohr , Roman Soták , Carol T. Zamfirescu

We determine the structure of linear maps on complex (real) square matrices sending unitary (orthogonal) matrices to multiples of unitary (orthogonal) matrices. The result is used to determine the linear preservers of matrix pairs…

Functional Analysis · Mathematics 2025-10-08 Bojan Kuzma , Chi-Kwong Li , Edward Poon

We give a complete classification of the ideals of the core of the C*-algebras associated with self-similar maps under a certain condition. Any ideal is completely determined by the intersection with the coefficient algebra C(K) of the…

Operator Algebras · Mathematics 2013-06-11 Tsuyoshi Kajiwara , Yasuo Watatani

We construct the "spectral" decomposition of the sets $\bar{Per\,f}$, $\omega(f)=\cup\omega(x)$ and $\Omega(f)$ for a continuous map $f$ of the interval to itself. Several corollaries are obtained; the main ones describe the generic…

Dynamical Systems · Mathematics 2016-01-25 Alexander M. Blokh

In this paper, we define the adjacency matrix of a semigraph. We give the conditions for a matrix to be semigraphical and give an algorithm to construct a semigraph from the semigraphical matrices. We derive lower and upper bounds for…

Spectral Theory · Mathematics 2022-05-03 Pralhad M. Shinde

In contrast to the usual quantum systems which have at most a finite number of open spectral gaps if they are periodic in more than one direction, periodic quantum graphs may have gaps arbitrarily high in the spectrum. This property of…

Quantum Physics · Physics 2020-05-26 Pavel Exner , Ondřej Turek

A graph is called pseudo-outerplanar if each block has an embedding on the plane in such a way that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another. In this…

Combinatorics · Mathematics 2011-10-20 Xin Zhang , Guizhen Liu , Jian-Liang Wu

In this paper, we study how the distance spectral radius behaves when the graph is perturbed by grafting edges. As applications, we also determine the graph with $k$ cut vertices (respectively, $k$ cut edges) with the minimal distance…

Spectral Theory · Mathematics 2010-11-10 Xiaoling Zhang , Chris Godsil

Cofibration categories are a formalization of homotopy theory useful for dealing with homotopy colimits that exist on the level of models as colimits of cofibrant diagrams. In this paper, we deal with their enriched version. Our main result…

Category Theory · Mathematics 2015-01-28 Lukáš Vokřínek

We define a graph to be $S$-regular if it contains an equitable partition given by a matrix $S$. These graphs are generalizations of both regular and bipartite, biregular graphs. An $S$-regular matrix is defined then as a matrix on an…

Combinatorics · Mathematics 2023-11-15 Matthew B. Crawford , David J. Marchette , William Maxwell , Samuel S. Mendelson

Sufficient conditions for a semigroup measure algebra to have contractible Gelfand spectrum are given and it is shown that for a wide class of semigroups these conditions are also necessary.

Functional Analysis · Mathematics 2019-03-08 A. R. Mirotin

We consider certain matrix-products where successive matrices in the product belong alternately to a particular qualitative class or its transpose. The main theorems relate structural and spectral properties of these matrix-products to the…

Combinatorics · Mathematics 2015-02-25 Murad Banaji , Carrie Rutherford

Using a new definition of a prime ideal of a skew brace A, on set Spec A of prime ideals of A we endow a spectral topology (in the sense of Grothendieck). We characterize irreducible closed subsets of Spec A and prove every irreducible…

Rings and Algebras · Mathematics 2025-04-29 Themba Dube , Amartya Goswami

When $\mathcal{C}$ is a chordal clutter in the sense of Woodroofe or Emtander, we show that the complement clutter is edgewise strongly shellable. When $\mathcal{C}$ is indeed a finite simple graph, we study various characterizations of…

Combinatorics · Mathematics 2016-04-20 Jin Guo , Yi-Huang Shen , Tongsuo Wu

In this note we extend the spectral theorem for bimodules to the higher rank graph C*-algebra context. Under the assumption that the graph is row finite and has no sources, we show that a bimodule over a natural abelian subalgebra is…

Operator Algebras · Mathematics 2007-05-23 Alan Hopenwasser

This paper outlines a program in what one might call spectral sheaf theory --- an extension of spectral graph theory to cellular sheaves. By lifting the combinatorial graph Laplacian to the Hodge Laplacian on a cellular sheaf of vector…

Algebraic Topology · Mathematics 2019-09-05 Jakob Hansen , Robert Ghrist

A graph is trivial if it contains one vertex and no edges. The essential connectivity $\kappa^{\prime}$ of $G$ is defined to be the minimum number of vertices of $G$ whose removal produces a disconnected graph with at least two non-trivial…

Combinatorics · Mathematics 2024-06-26 Wenxiu Ding , Dan Li , Yu Wang , Jixiang Meng