Results 61 to 70 of about 238,303 (293)

Spectral mapping theorems and perturbation theorems for Browder’s essential spectrum [PDF]

Transactions of the American Mathematical Society, 1970
If T T is a closed, densely defined linear operator in a Banach space, F. E. Browder has defined the essential spectrum of T , ess ⁡ ( T ) T,\operatorname {ess} (T) [1]. We derive below spectral mapping theorems and perturbation theorems for Browder’s essential spectrum.
openaire   +1 more source

Unique Performance Considerations for Printable Organic Semiconductor and Perovskite Radiation Detectors: Toward Consensus on Best Practice Evaluation

Advanced Functional Materials, EarlyView.
A lack of standard approaches for testing and reporting the performance of metal halide perovskites and organic semiconductor radiation detectors has resulted in inconsistent interpretation of performance parameters, impeding progress in the field. This Perspective recommends key metrics and experimental details, which are suggested for reporting in ...
Jessie A. Posar, Matthew Large, Andrea Ciavatti, Laura Basiricò, Beatrice Fraboni, Paul J. Sellin, Attila J. Mozer, Marco Petasecca, Matthew J. Griffith   +8 more
wiley   +1 more source

Quantum Emitters in Hexagonal Boron Nitride: Principles, Engineering and Applications

Advanced Functional Materials, EarlyView.
Quantum emitters in hexagonal boron nitride have emerged as a promising candidate for quantum information science. This review examines the fundamentals of these quantum emitters, including their level structures, defect engineering, and their possible chemical structures.
Thi Ngoc Anh Mai, Md Shakhawath Hossain, Nhat Minh Nguyen, Yongliang Chen, Chaohao Chen, Xiaoxue Xu, Quang Thang Trinh, Toan Dinh, Toan Trong Tran   +8 more
wiley   +1 more source

Universal Electronic‐Structure Relationship Governing Intrinsic Magnetic Properties in Permanent Magnets

Advanced Functional Materials, EarlyView.
Permanent magnets derive their extraordinary strength from deep, universal electronic‐structure principles that control magnetization, anisotropy, and intrinsic performance. This work uncovers those governing rules, examines modern modeling and AI‐driven discovery methods, identifies critical bottlenecks, and reveals electronic fingerprints shared ...
Prashant Singh
wiley   +1 more source

Global Perturbation of Nonlinear Eigenvalues

Advanced Nonlinear Studies, 2021
This paper generalizes the classical theory of perturbation of eigenvalues up to cover the most general setting where the operator surface 𝔏:[a,b]×[c,d]→Φ0⁢(U,V){\mathfrak{L}:[a,b]\times[c,d]\to\Phi_{0}(U,V)}, (λ,μ)↦𝔏⁢(λ,μ){(\lambda,\mu)\mapsto\mathfrak ...
López-Gómez Julián, Sampedro Juan Carlos   +1 more
doaj   +1 more source

On the boundary value problems of piecewise differential equations with left-right fractional derivatives and delay

Nonlinear Analysis, 2021
In this paper, we study the multi-point boundary value problems for a new kind of piecewise differential equations with left and right fractional derivatives and delay. In this system, the state variables satisfy the different equations in different time
Yuxin Zhang, Xiping Liu, Mei Jia
doaj   +1 more source

Two loops calculation in chiral perturbation theory and the unitarization program of current algebra [PDF]

, 1997
In this paper we compare two loop Chiral Perturbation Theory (ChPT) calculation of pion-pion scattering with the unitarity second order correction to the current algebra soft-pion theorem. It is shown that both methods lead to the same analytic structure
A. Dobado, A. Dobado, G. Ecker, I. S. Gerstein, J. Bijnens, J. Gasser, J. Gasser, J. Soares Barbosa, J. Sá Borges, J. Sá Borges, J. Sá Borges, J. Sá Borges, J. Sá Borges, M. D. Tonasse, M. Knecht, S. Weinberg, S. Weinberg   +16 more
core   +2 more sources

Weyl's theorem for perturbations of paranormal operators [PDF]

Proceedings of the American Mathematical Society, 2007
A bounded operator \(T\) is said to be algebraic if there exists a nontrivial polynomial \(q\) such that \(q(T)=0\). Let \(T\) and \(K\) be paranormal and algebraic operators on a Hilbert space, respectively. In this paper, the authors show that if \(TK=KT\), then Weyl's theorem holds for \(T+K\). This says that \textit{M.\,Oudghiri}'s result [Integral
Aiena, Pietro, Guillen, Jesús R.
openaire   +1 more source

Spin‐Split Edge States in Metal‐Supported Graphene Nanoislands Obtained by CVD

Advanced Materials, EarlyView.
Combining STM measurements and ab‐initio calculations, we show that zig‐zag edges in graphene nanoislands grown on Ni(111) by CVD retrieve their spin‐polarized edge states after intercalation of a few monolayers of Au. ABSTRACT Spin‐split states localized on zigzag edges have been predicted for different free‐standing graphene nanostructures.
Michele Gastaldo, Masoud Mansouri, Carlos Garcia‐Fernandez, Daniel Sánchez‐Portal, Aran Garcia‐Lekue, Gustavo Ceballos, Aitor Mugarza   +6 more
wiley   +1 more source

Comment on soft-pion emission in DVCS

, 2005
The soft-pion theorem for pion production in deeply virtual Compton scattering, derived by Guichon, Mosse and Vanderhaegen, is shown to be consistent with chiral perturbation theory. Chiral symmetry requires that the nonsinglet operators corresponding to
Ecker G, Kivel N Polyakov M V Stratmann S, Michael C Birse   +2 more
core   +1 more source