Results 61 to 70 of about 672,117 (260)

Randi'c incidence energy of graphs [PDF]

open access: yesTransactions on Combinatorics, 2014
Let $G$ be a simple graph with vertex set $V(G) = {v_1, v_2,ldots , v_n}$ and edge set $E(G) = {e_1, e_2,ldots , e_m}$. Similar to the Randi'c matrix, here we introduce the Randi'c incidence matrix of a graph $G$, denoted by $I_R(G)$, which is defined
Ran Gu, Fei Huang, Xueliang Li
doaj  

A recursive condition for the symmetric nonnegative inverse eigenvalue problem

open access: yesRevista Integración, 2017
In this paper we present a sufficient ondition and a necessary condition for Symmetri Nonnegative Inverse Eigenvalue Problem. This condition is independent of the existing realizability criteria.
Elvis Ronald Valero   +2 more
doaj   +1 more source

On the Approximation of Isolated Eigenvalues of Ordinary Differential Operators

open access: yes, 2007
We extend a result of Stolz and Weidmann on the approximation of isolated eigenvalues of singular Sturm-Liouville and Dirac operators by the eigenvalues of regular operators.Comment: 4 ...
Communicated Joseph A. Ball   +1 more
core   +2 more sources

Pentagonal 2D Altermagnets: Material Screening and Altermagnetic Tunneling Junction Device Application

open access: yesAdvanced Functional Materials, EarlyView.
From a database of 170 pentagonal 2D materials, 4 candidates exhibiting altermagnetic ordering are screened. Furthermore, the spin‐splitting and unconventional boundary states in the pentagonal 2D altermagnetic monolayer MnS2 are investigated. A MnS2‐based altermagnetic tunneling junction is designed and, through ab initio quantum transport simulations,
Jianhua Wang   +8 more
wiley   +1 more source

Shape optimization for an elliptic operator with infinitely many positive and negative eigenvalues

open access: yesAdvances in Nonlinear Analysis, 2018
This paper deals with an eigenvalue problem possessing infinitely many positive and negative eigenvalues. Inequalities for the smallest positive and the largest negative eigenvalues, which have the same properties as the fundamental frequency, are ...
Bandle Catherine, Wagner Alfred
doaj   +1 more source

Algebraic conditions and the sparsity of spectrally arbitrary patterns

open access: yesSpecial Matrices, 2021
Given a square matrix A, replacing each of its nonzero entries with the symbol * gives its zero-nonzero pattern. Such a pattern is said to be spectrally arbitrary when it carries essentially no information about the eigenvalues of A.
Deaett Louis, Garnett Colin
doaj   +1 more source

Oscillation and spectral properties of some classes of higher order differential operators and weighted $n$th order differential inequalities

open access: yesElectronic Journal of Qualitative Theory of Differential Equations, 2021
In this paper, we obtain strong oscillation and non-oscillation conditions for a class of higher order differential equations in dependence on an integral behavior of its coefficients in a neighborhood of infinity.
Aigerim Kalybay   +2 more
doaj   +1 more source

Mechanical Properties of Architected Polymer Lattice Materials: A Comparative Study of Additive Manufacturing and CAD Using FEM and µ‐CT

open access: yesAdvanced Functional Materials, EarlyView.
This study examines how pore shape and manufacturing‐induced deviations affect the mechanical properties of 3D‐printed lattice materials with constant porosity. Combining µ‐CT analysis, FEM, and compression testing, the authors show that structural imperfections reduce stiffness and strength, while bulk material inhomogeneities probably enhance ...
Oliver Walker   +5 more
wiley   +1 more source

Fractional Sturm–Liouville Eigenvalue Problems, II

open access: yesFractal and Fractional, 2022
We continue the study of a non-self-adjoint fractional three-term Sturm–Liouville boundary value problem (with a potential term) formed by the composition of a left Caputo and left Riemann–Liouville fractional integral under Dirichlet type boundary ...
Mohammad Dehghan, Angelo B. Mingarelli
doaj   +1 more source

Electric Field‐Dependent Conductivity as Probe for Charge Carrier Delocalization and Morphology in Organic Semiconductors

open access: yesAdvanced Functional Materials, EarlyView.
Applying a high electric field to a doped organic semiconductor heats up the charge carrier distribution beyond the lattice temperature, enhancing conductivity. It is shown that the associated effective temperature can be used to extract the effective localization length, which is a characteristic length scale of charge transport and provides ...
Morteza Shokrani   +4 more
wiley   +1 more source

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