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Related papers: Momentum operators on graphs

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In this paper, we consider certain elements in von Neumann algebras generated by graph groupoids. In particular, we are interested in finitely supported elements, called graph operators. We study the characterizations for self-adjointness,…

Representation Theory · Mathematics 2010-07-20 Ilwoo Cho , Palle E. T. Jorgensen

We consider the space-fractional operator with order $0<\alpha<1$ on the metric star graph. The boundary conditions at the vertices of the metric star graph providing the self-adjointness of the operator are derived. The obtained result is…

Spectral Theory · Mathematics 2023-05-03 K. K. Sabirov , R. R. Ashurov

We address the question of convergence of Schr\"odinger operators on metric graphs with general self-adjoint vertex conditions as lengths of some of graph's edges shrink to zero. We determine the limiting operator and study convergence in a…

Spectral Theory · Mathematics 2019-10-23 Gregory Berkolaiko , Yuri Latushkin , Selim Sukhtaiev

As graph representations of data emerge in multiple domains, data analysts need to be able to intelligently select among a magnitude of different data graphs based on the effects different graph operators have on them. Exhaustive execution…

Social and Information Networks · Computer Science 2018-08-21 Tasos Bakogiannis , Ioannis Giannakopoulos , Dimitrios Tsoumakos , Nectarios Koziris

We consider boundary conditions at the vertex of a star graph which make Schroedinger operators on the graph self-adjoint, in particular, the two-parameter family of such conditions invariant with respect to permutations of graph edges. It…

Mathematical Physics · Physics 2007-05-23 Pavel Exner , Ondrej Turek

We consider metric graphs with a uniform lower bound on the edge lengths but no further restrictions. We discuss how to describe every local self-adjoint Laplace operator on such graphs by boundary conditions in the vertices given by…

Mathematical Physics · Physics 2018-09-28 Daniel Lenz , Carsten Schubert , Ivan Veselić

We establish several new relations between the discrete transition operator, the continuous Laplacian and the averaging operator associated with combinatorial and metric graphs. It is shown that these operators can be expressed through each…

Spectral Theory · Mathematics 2016-03-11 Daniel Lenz , Konstantin Pankrashkin

On finite metric graphs we consider Laplace operators, subject to various classes of non-self-adjoint boundary conditions imposed at graph vertices. We investigate spectral properties, existence of a Riesz basis of projectors and similarity…

Spectral Theory · Mathematics 2021-03-30 Amru Hussein , David Krejcirik , Petr Siegl

A graph operator is a mapping $\phi$ which maps every graph $G$ from some class of graphs to a new graph $\phi(G)$. In this paper, we introduce and study the properties of the mincut operator, specifically the effects of iteration of the…

Combinatorics · Mathematics 2025-01-28 Christo Kriel , Eunice Mphako-Banda

A Riemann-Roch theorem on graph was initiated by M. Baker and S. Norine. In their article [2], a Riemann-Roch theorem on a finite graph with uniform vertex-weight and uniform edge-weight was established and it was suggested a Riemann-Roch…

Combinatorics · Mathematics 2022-01-20 Atsushi Atsuji , Hiroshi Kaneko

Several graph properties are characterized as the class of graphs that admit an orientation avoiding finitely many oriented structures. For instance, if $F_k$ is the set of homomorphic images of the directed path on $k+1$ vertices, then a…

Combinatorics · Mathematics 2020-12-24 Santiago Guzmán-Pro , César Hernández-Cruz

We expand on some invariants used for classifying nonselfadjoint operator algebras. Specifically to nonselfadjoint operator algebras which have a conditional expectation onto a commutative diagonal we construct an edge-colored directed…

Operator Algebras · Mathematics 2013-07-23 Benton Duncan

Operator learning has been highly successful for continuous mappings between infinite-dimensional spaces, such as PDE solution operators. However, many operators of interest-including differential operators-are discontinuous or set-valued,…

Machine Learning · Computer Science 2026-05-13 Takashi Furuya , Yury Korolev , Takaharu Yaguchi

In this paper we propose a model for describing advection dynamics on distance-weighted directed graphs. To this end we establish a set of key properties, or axioms, that a discrete advection operator should satisfy, and prove that there…

Social and Information Networks · Computer Science 2025-03-26 Michele Benzi , Fabio Durastante , Francesco Zigliotto

This paper studies infinite graphs produced from a natural unfolding operation applied to finite graphs. Graphs produced via such operations are of finite degree and automatic over the unary alphabet (that is, they can be described by…

Logic · Mathematics 2008-09-22 Bakhadyr Khoussainov , Jiamou Liu , Mia Minnes

We study the influence of certain geometric perturbations on the spectra of self-adjoint Schr\"odinger operators on compact metric graphs. Results are obtained for permutation invariant vertex conditions, which, amongst others, include…

Spectral Theory · Mathematics 2018-09-19 Jonathan Rohleder , Christian Seifert

We define the independence ratio and the chromatic number for bounded, self-adjoint operators on an L^2-space by extending the definitions for the adjacency matrix of finite graphs. In analogy to the Hoffman bounds for finite graphs, we…

Functional Analysis · Mathematics 2014-10-07 Christine Bachoc , Evan DeCorte , Fernando Mario de Oliveira Filho , Frank Vallentin

We study topological boundedness of order-to-topology bounded and order-to-topology continuous operators from ordered vector spaces to topological vector spaces. The uniform boundedness principle for such operators is investigated.

Functional Analysis · Mathematics 2026-03-12 Eduard Emelyanov

We present the operator semigroups approach to first- and second-order dynamical systems taking place on metric graphs. We briefly survey the existing results and focus on the well-posedness of the problems with standard vertex conditions.…

Analysis of PDEs · Mathematics 2020-09-22 Marjeta Kramar Fijavž , Aleksandra Puchalska

We consider various systematic ways of defining unbounded operator valued integrals of complex functions with respect to (mostly) positive operator measures and positive sesquilinear form measures, and investigate their relationships to…

Functional Analysis · Mathematics 2014-02-28 Daniel Dubin , Jukka Kiukas , Juha-Pekka Pellonpää , Kari Ylinen
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