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Related papers: The Dirac operator of a graph

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We study extensions of direct sums of symmetric operators $S=\oplus_{n\in\mathbb{N}} S_n$. In general there is no natural boundary triplet for $S^*$ even if there is one for every $S_n^*$, $n\in\mathbb{N}$. We consider a subclass of…

Spectral Theory · Mathematics 2018-06-12 Hannes Gernandt , Carsten Trunk

We study families of self-adjoint operators with given spectra whose sum is a scalar operator. Such families are $*$-representations of certain algebras which can be described in terms of graphs and positive functions on them. The main…

Representation Theory · Mathematics 2007-05-23 Vasyl Ostrovskyi

This introductory presentation describes the Overlap Dirac Operator, why it could be useful in numerical QCD, and how it can be implemented.

High Energy Physics - Lattice · Physics 2007-05-23 H. Neuberger

We review the exact results for microscopic Dirac operator spectra based on either Random Matrix Theory, or, equivalently, chiral Lagrangians. Implications for lattice calculations are discussed.

High Energy Physics - Lattice · Physics 2007-05-23 P. H. Damgaard

As an outgrowth of our investigation of non-regular spaces within the context of quantum gravity and non-commutative geometry, we develop a graph Hilbert space framework on arbitrary (infinite) graphs and use it to study spectral properties…

Mathematical Physics · Physics 2016-09-07 Manfred Requardt

It has been shown recently that Dirac operators satisfying the Ginsparg-Wilson relation provide a solution of the chirality problem in QCD at finite lattice spacing. We discuss different ways to construct these operators and their…

High Energy Physics - Lattice · Physics 2011-07-19 Ferenc Niedermayer

We derive the spectrum of the Dirac operator for the linear sigma-model with quarks in the large N_c approximation using renormalization group flow equations. For small eigenvalues, the Banks-Casher relation and the vanishing linear term…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. Spitzenberg , K. Schwenzer , H. -J. Pirner

The divisibility graph $D(G)$ for a finite group $G$ is a graph with vertex set $cs~(G)\setminus\{1\}$ where $cs~(G)$ is the set of conjugacy class sizes of $G$. Two vertices $a$ and $b$ are adjacent whenever $a$ divides $b$ or $b$ divides…

Group Theory · Mathematics 2014-07-17 Adeleh Abdolghafourian , Mohammad A. Iranmanesh

We present a numerical study of the properties of the Fixed Point lattice Dirac operator in the Schwinger model. We verify the theoretical bounds on the spectrum, the existence of exact zero modes with definite chirality, and the Index…

High Energy Physics - Lattice · Physics 2009-10-31 Federico Farchioni , Victor Laliena

We consider the linear Dirac operator with a (-1)-homogeneous locally periodic potential that varies with respect to a small parameter. Using the notation of G-convergence for positive self-adjoint operators in Hilbert spaces we prove…

Functional Analysis · Mathematics 2012-03-22 Hasan Almanasreh , Nils Svanstedt

We present a matrix technique to obtain the spectrum and the analytical index of some elliptic operators defined on compact Riemannian manifolds. The method uses matrix representations of the derivative which yield exact values for the…

High Energy Physics - Lattice · Physics 2008-11-26 R. G. Campos , J. L. Lopez-Lopez , R. Vera

Characterization of k-chordal graphs based on the existence of a "simplicial path" was shown in [Chv{\'a}tal et al. Note: Dirac-type characterizations of graphs without long chordless cycles. Discrete Mathematics, 256, 445-448, 2002]. We…

Combinatorics · Mathematics 2013-01-01 R. Krithika , Rogers Mathew , N. S. Narayanaswamy , N. Sadagopan

We discuss how to formulate Dirac fermion operator on a finite lattice such that it can provide a nonperturbative regularization for massless fermion interacting with a background gauge field.

High Energy Physics - Lattice · Physics 2011-02-16 Ting-Wai Chiu

This paper is devoted to a fundamental system of equations in Linear Elasticity Theory: the famous Lam\'e-Navier system. The Clifford algebra language allows us to rewrite this system in terms of the euclidean Dirac operator, which at the…

Suppose a finite, unweighted, combinatorial graph $G = (V,E)$ is the union of several (degree-)regular graphs which are then additionally connected with a few additional edges. $G$ will then have only a small number of vertices $v \in V$…

Combinatorics · Mathematics 2023-10-25 Tony Zeng

In this work we study a linear operator $f$ on a pre-euclidean space $\mathcal{V}$ by using properties of a corresponding graph. Given a basis $\B$ of $\mathcal{V}$, we present a decomposition of $\mathcal{V}$ as an orthogonal direct sum of…

Representation Theory · Mathematics 2024-01-24 Hani Abdelwahab , Elisabete Barreiro , Antonio J. Calderón , José M. Sánchez

We propose a differential analog of the notion of integral closure of algebraic function fields. We present an algorithm for computing the integral closure of the algebra defined by a linear differential operator. Our algorithm is a direct…

Symbolic Computation · Computer Science 2015-07-01 Manuel Kauers , Christoph Koutschan

Fundamental solutions of Dirac type operators are introduced for a class of conformally flat manifolds. This class consists of manifolds obtained by factoring out the upper half-space of $\mathbb{R}^n$ by arithmetic subgroups of generalized…

Analysis of PDEs · Mathematics 2007-05-23 Elizabeth Bulla , Denis Constales , Rolf Soeren Krausshar , John Ryan

A biclique of a graph $G$ is a maximal induced complete bipartite subgraph of $G$. The edge-biclique graph of $G$, $KB_e(G)$, is the edge-intersection graph of the bicliques of $G$. A graph $G$ diverges (resp. converges or is periodic)…

Discrete Mathematics · Computer Science 2021-11-30 Leandro Montero , Sylvain Legay

The dominance complex $D(G)$ of a simple graph $G = (V,E)$ is the simplicial complex consisting of the subsets of $V$ whose complements are dominating. We show that the connectivity of $D(G)$ plus $2$ is a lower bound for the vertex cover…

Combinatorics · Mathematics 2022-12-06 Takahiro Matsushita