English
Related papers

Related papers: A note on Ambarzumian's theorem for quantum graphs

200 papers

We develop an equivariant theory of graphs with respect to quantum symmetries and present a detailed exposition of various examples. We portray unitary tensor categories as a unifying framework encompassing all finite classical simple…

Operator Algebras · Mathematics 2026-01-06 Michael Brannan , Roberto Hernández Palomares

The classical sampling theorem for bandlimited functions has recently been generalized to apply to so-called bandlimited operators, that is, to operators with band-limited Kohn-Nirenberg symbols. Here, we discuss operator sampling versions…

Functional Analysis · Mathematics 2009-03-06 Yoon Mi Hong , Goetz E. Pfander

We provide in this Letter a two-point generalisation of the Agmon estimate for Schr\"odinger operators on graphs recently established by S. Steinerberger. It reduces to his estimate when the two points belong to different sets separated by…

Spectral Theory · Mathematics 2024-05-14 Yi C. Huang

We undertake a study of the notion of a quantum graph over arbitrary finite-dimensional $C^*$-algebras $B$ equipped with arbitrary faithful states. Quantum graphs are realised principally as either certain operators on $L^2(B)$, the quantum…

Operator Algebras · Mathematics 2024-11-27 Matthew Daws

We introduce the notion of a diagram category and discuss its application to the invariant theory of classical groups and super groups, with some indications concerning extensions to quantum groups and quantum super groups. Tensor functors…

Representation Theory · Mathematics 2022-11-09 G. I. Lehrer , R. B. Zhang

We present an integral formulation of the vacuum energy of Schr\"odinger operators on finite metric graphs. Local vertex matching conditions on the graph are classified according to the general scheme of Kostrykin and Schrader. While the…

Mathematical Physics · Physics 2015-06-03 J. M. Harrison , K. Kirsten

We introduce quantum hypergraphs, in analogy with the theory of quantum graphs developed over the last 15 years by many authors. We emphasize some problems that arise when one tries to define a Laplacian on a hypergraph.

Mathematical Physics · Physics 2018-07-26 Delio Mugnolo

A compact review is given, and a few new numerical results are added to the recent studies of the q-pointed one-dimensional star-shaped quantum graphs. These graphs are assumed endowed with certain specific, manifestly non-Hermitian point…

Quantum Physics · Physics 2013-06-28 Miloslav Znojil

We construct the quantum curve for the Baker-Akhiezer function of the orbifold Gromov-Witten theory of the weighted projective line $\mathbb P[r]$. Furthermore, we deduce the explicit bilinear Fermionic formula for the (stationary)…

Mathematical Physics · Physics 2019-12-03 Chongyao Chen , Shuai Guo

We introduce the weighted graph Laplacian and the notion of Schr\"odinger operator on a locally finite weighted graph. Concerning essential self-adjointness, we extend Wojciechowski's and Dodziuk's results for graphs with vertex constant…

Spectral Theory · Mathematics 2012-01-25 Nabila Torki-Hamza

With appropriate notions of Hermitian vector bundles and connections over weighted graphs which we allow to be locally infinite, we prove Feynman-Kac-type representations for the corresponding semigroups and derive several applications…

Mathematical Physics · Physics 2013-06-26 Batu Gûneysu , Ognjen Milatovic , Francoise Truc

We derive a counting formula for the eigenvalues of Schr\"odinger operators with self-adjoint boundary conditions on quantum star graphs. More specifically, we develop techniques using Evans functions to reduce full quantum graph eigenvalue…

Spectral Theory · Mathematics 2024-02-13 Nathaniel Smith , Alim Sukhtayev

In some previous works, the analytic structure of the spectrum of a quantum graph operator as a function of the vertex conditions and other parameters of the graph was established. However, a specific local coordinate chart on the…

Mathematical Physics · Physics 2019-10-02 Peter Kuchment , Jia Zhao

We study Cantor's powerset theorem from a graph-theoretic perspective, consider some alternative proofs to Cantor's original, and provide a new proof.

History and Overview · Mathematics 2026-02-17 Saeed Salehi

Discrete versions of the Laplace and Dirac operators haven been studied in the context of combinatorial models of statistical mechanics and quantum field theory. In this paper we introduce several variations of the Laplace and Dirac…

Mathematical Physics · Physics 2022-03-08 Beata Casiday , Ivan Contreras , Thomas Meyer , Sabrina Mi , Ethan Spingarn

We give a common matroidal generalisation of `A Cantor-Bernstein theorem for paths in graphs' by Diestel and Thomassen and `A Cantor-Bernstein-type theorem for spanning trees in infinite graphs' by ourselves.

Combinatorics · Mathematics 2022-05-10 Attila Joó

We begin with the characterization of quantum graphs as left ideals in $\mathcal M \otimes_{eh} \mathcal M$ (the extended Haagerup tensor product of $\mathcal M$ with itself) to avoid technicalities surrounding representation dependence of…

Operator Algebras · Mathematics 2026-05-14 Jennifer Zhu

In this note, we present a simple non-directed graph proof of Sharkovsky's theorem which is different from the one given in [2].

Dynamical Systems · Mathematics 2007-05-23 Bau-Sen Du

We discuss approximations of vertex couplings of quantum graphs using families of thin branched manifolds. We show that if a Neumann type Laplacian on such manifolds is amended by suitable potentials, the resulting Schr\"odinger operators…

Mathematical Physics · Physics 2008-11-25 Pavel Exner , Olaf Post

We consider quantum graphs with transparent branching points. To design such networks, the concept of transparent boundary conditions is applied to the derivation of the vertex boundary conditions for the linear Schrodinger equation on…

Quantum Physics · Physics 2019-06-26 J. R. Yusupov , K. K. Sabirov , M. Ehrhardt , D. U. Matrasulov