Results 71 to 80 of about 20,701 (195)

A note on Tauberian operators

International Journal of Mathematics and Mathematical Sciences, 1990
In this note we prove the existence of operators which are not Tauberian even though they satisfy properties about restrictions being Tauberian. The operators are defined on Banach spaces which contain a somewhat reflexive, non-reflexive subspace.
Jesús Araujo, J. Martinez-Maurica
doaj   +1 more source

Scattering theory for difference equations with operator coefficients

Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract We investigate a class of second‐order difference equations featuring operator‐valued coefficients with the aim of approaching problems of stationary scattering theory. We focus on various compact perturbations of the discrete Laplacian given in a Hilbert space of bi‐infinite square‐summable sequences with entries from a fixed Hilbert space ...
David Sher, Luis Silva, Boris Vertman, Monika Winklmeier   +3 more
wiley   +1 more source

Unitary ensembles with a critical edge point, their multiplicative statistics, and the Korteweg‐de‐Vries hierarchy

Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract We study the multiplicative statistics associated to the limiting determinantal point process describing eigenvalues of unitary random matrices with a critical edge point, where the limiting eigenvalue density vanishes like a power 5/2. We prove that these statistics are governed by the first three equations of the Korteweg‐de‐Vries (KdV ...
Mattia Cafasso, Carla Mariana da Silva Pinheiro   +1 more
wiley   +1 more source

Harmonic maps to the circle with higher dimensional singular set

Proceedings of the London Mathematical Society, Volume 132, Issue 3, March 2026.
Abstract In a closed, oriented ambient manifold (Mn,g)$(M^n,g)$ we consider the problem of finding S1$\mathbb {S}^1$‐valued harmonic maps with prescribed singular set. We show that the boundary of any oriented (n−1)$(n-1)$‐submanifold can be realised as the singular set of an S1$\mathbb {S}^1$‐valued map, which is classically harmonic away from the ...
Marco Badran
wiley   +1 more source

Fredholm Operators and Spectral Flow [PDF]

, 2016
These are extended lecture notes of a PhD course that the author gave at the Universita degli studi di Torino in Italy in spring 2013.
openaire   +3 more sources

Construction of a Multitissue Cell Atlas Reveals Cell‐Type‐Specific Regulation of Molecular and Complex Phenotypes in Pigs

Advanced Science, Volume 13, Issue 8, 9 February 2026.
This research conducts an in‐depth investigation of cell‐type‐specific regulatory mechanisms underlying molecular and complex phenotypes through integrative analysis of multitissue single‐nucleus RNA sequencing, bulk RNA‐seq, and genome‐wide association study (GWAS) data in pigs.
Lijuan Chen, Houcheng Li, Jinyan Teng, Zhen Wang, Xiaolu Qu, Zhe Chen, Xiaodian Cai, Haonan Zeng, Zhonghao Bai, Jinghui Li, Xiangchun Pan, Leyan Yan, Fei Wang, Lin Lin, Yonglun Luo, Goutam Sahana, Mogens Sandø Lund, Maria Ballester, Daniel Crespo‐Piazuelo, Peter Karlskov‐Mortensen, Merete Fredholm, Alex Clop, Marcel Amills, Crystal Loving, Christopher K. Tuggle, Ole Madsen, Jiaqi Li, Zhe Zhang, George E. Liu, Jicai Jiang, Lingzhao Fang, Guoqiang Yi   +31 more
wiley   +1 more source

Fredholm Property of Matrix Wiener-Hopf plus and minus Hankel Operators with Semi-Almost Periodic Symbols

Cubo, 2010
We will present sufficient conditions for the Fredholm property of Wiener-Hopf plus and minus Hankel operators with different Fourier matrix symbols in the C*-algebra of semialmost periodic elements.
L. P Castro, A. S. Silva
doaj  

Bifurcation theory for Fredholm operators

Journal of Differential Equations
This paper consists of four parts. It begins by using the authors's generalized Schauder formula, [50], and the algebraic multiplicity, $χ$, of Esquinas and López-Gómez [18,17,40] to package and sharpening all existing results in local and global bifurcation theory for Fredholm operators through the recent author's axiomatization of the Fitzpatrick ...
Julián López-Gómez, Juan Carlos Sampedro   +1 more
openaire   +3 more sources

Maxwell Fronts in the Discrete Nonlinear Schrödinger Equations With Competing Nonlinearities

Studies in Applied Mathematics, Volume 156, Issue 2, February 2026.
ABSTRACT In discrete nonlinear systems, the study of nonlinear waves has revealed intriguing phenomena in various fields such as nonlinear optics, biophysics, and condensed matter physics. Discrete nonlinear Schrödinger (DNLS) equations are often employed to model these dynamics, particularly in the context of Bose–Einstein condensates and optical ...
Farrell Theodore Adriano, Hadi Susanto
wiley   +1 more source

Some New Properties in Fredholm Theory, Schechter Essential Spectrum, and Application to Transport Theory

Journal of Inequalities and Applications, 2008
The theory of measures of noncompactness has many applications on topology, functional analysis, and operator theory. In this paper, we consider one axiomatic approach to this notion which includes the most important classical definitions.
Dehici Abdelkader, Abdelmoumen Boulbeba, Jeribi Aref, Mnif Maher   +3 more
doaj