Results 51 to 60 of about 613,974 (314)
Biometrika, 2020 Summary The properties of penalized sample covariance matrices depend on the choice of the penalty function. In this paper, we introduce a class of nonsmooth penalty functions for the sample covariance matrix and demonstrate how their use results in a grouping of the estimated eigenvalues.
Tyler, David E., Yi, Mengxi
openaire +2 more sources
Analyzing Electronic Excitations and Exciton Binding Energies in Y6 Films
Advanced Functional Materials, EarlyView.The Y6 molecule is used for increasing the efficiency of organic solar cells. The exciton binding energy is calculated for ensembles of Y6 molecules that are representative of the typically used films. The calculations show that the excitons typically spread out over many molecules.
Sahar Javaid Akram +2 more
wiley +1 more source
Quasi-isospectrality on quantum graphs [PDF]
, 2014 Consider two quantum graphs with the standard Laplace operator and non-Robin type boundary conditions at all vertices. We show that if their eigenvalue-spectra agree everywhere aside from a sufficiently sparse set, then the eigenvalue-spectra and the ...
Rueckriemen, Ralf
core
A constrained eigenvalue problem [PDF]
Linear Algebra and its Applications, 1989 ETH, Eidgenössische Technische Hochschule Zürich, Institut für Informatik, Fachgruppe Wissenschaftliches Rechnen ...
Gander, Walter +2 more
openaire +4 more sources
Advanced Functional Materials, EarlyView.This study uncovers the unexplored role of intermolecular interactions in multiphoton absorption in coordination polymers. By analyzing [Zn2tpda(DMA)2(DMF)0.3], it shows how the electronic coupling of the chromophores and confinement in the MOF enhance two‐and three‐photon absorption.
Simon Nicolas Deger +11 more
wiley +1 more source
BOUNDARY VALUE PROBLEM FOR DIFFERENTIAL EQUATION WITH FRACTIONAL ORDER DERIVATIVES WITH DIFFERENT ORIGINS [PDF]
Vestnik KRAUNC: Fiziko-Matematičeskie Nauki, 2015 We study a spectral problem for an ordinary differential equation with composition of fractional order differentiation operators in Riemann-Liouville and Caputo senses with different origins. We prove that for the problem under study there exist infinite
L.M. Eneeva
doaj +1 more source
The Largest Laplacian and Signless Laplacian H-Eigenvalues of a Uniform Hypergraph [PDF]
, 2013 In this paper, we show that the largest Laplacian H-eigenvalue of a $k$-uniform nontrivial hypergraph is strictly larger than the maximum degree when $k$ is even. A tight lower bound for this eigenvalue is given.
Hu, Shenglong, Qi, Liqun, Xie, Jinshan
core
Advanced Functional Materials, EarlyView.A spin group (SG)‐based mechanism is proposed to realize a single pair of Weyl points. PT‐symmetric nodal lines (NLs) persist under T‐breaking, protected by the combination of SG and P symmetry. When considering spin‐orbit coupling, the SG‐protected NL will split into Weyl points, which will also induce anomalous transport phenomena arising from ...
Shifeng Qian +6 more
wiley +1 more source
Mathematics, 2022 A new stochastic approach for the approximation of (nonlinear) Lipschitz operators in normed spaces by their eigenvectors is shown. Different ways of providing integral representations for these approximations are proposed, depending on the properties of
Ezgi Erdoğan +1 more
doaj +1 more source
Eigenvalue comparisons in Steklov eigenvalue problem and some other eigenvalue estimates [PDF]
Revista Matemática Complutense, 2019 Comments are welcome. 24 pages.
Feng Du +4 more
openaire +3 more sources