Results 71 to 80 of about 38,188 (251)
Sobolev spaces and boundary-value problems for the curl and gradient-of-divergence operators
Vestnik Samarskogo Gosudarstvennogo Tehničeskogo Universiteta. Seriâ: Fiziko-Matematičeskie Nauki, 2020 We study boundary value and spectral problems in a bounded domain $G$ with smooth border for operators $\operatorname{rot} +\lambda I$ and $\nabla \operatorname{div} +\lambda I$ in the Sobolev spaces. For $\lambda\neq 0$ these operators are reducible (by
Romen Semenovich Saks
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Discretized Laplacians on an Interval and their Renormalization Group
, 1993 The Laplace operator admits infinite self-adjoint extensions when considered on a segment of the real line. They have different domains of essential self-adjointness characterized by a suitable set of boundary conditions on the wave functions.
Bimonte, G. +2 more
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Self-Adjoint Extensions by Additive Perturbations
, 2001 Let $A_\N$ be the symmetric operator given by the restriction of $A$ to $\N$, where $A$ is a self-adjoint operator on the Hilbert space $\H$ and $\N$ is a linear dense set which is closed with respect to the graph norm on $D(A)$, the operator domain of $A$.
openaire +4 more sources
Degree theory for 4‐dimensional asymptotically conical gradient expanding solitons
Communications on Pure and Applied Mathematics, Volume 79, Issue 5, Page 1151-1298, May 2026.Abstract We develop a new degree theory for 4‐dimensional, asymptotically conical gradient expanding solitons. Our theory implies the existence of gradient expanding solitons that are asymptotic to any given cone over S3$S^3$ with non‐negative scalar curvature. We also obtain a similar existence result for cones whose link is diffeomorphic to S3/Γ$S^3/\
Richard H. Bamler, Eric Chen
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Dirac lattices, zero-range potentials, and self-adjoint extension [PDF]
Physical Review D, 2015 We consider the electromagnetic field in the presence of polarizable point dipoles. In the corresponding effective Maxwell equation these dipoles are described by three dimensional delta function potentials. We review the approaches handling these: the selfadjoint extension, regularization/renormalisation and the zero range potential methods.
Bordag, M., Munoz-Castaneda, J. M.
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Isoperimetric inequalities on slabs with applications to cubes and Gaussian slabs
Communications on Pure and Applied Mathematics, Volume 79, Issue 4, Page 1012-1072, April 2026.Abstract We study isoperimetric inequalities on “slabs”, namely weighted Riemannian manifolds obtained as the product of the uniform measure on a finite length interval with a codimension‐one base. As our two main applications, we consider the case when the base is the flat torus R2/2Z2$\mathbb {R}^2 / 2 \mathbb {Z}^2$ and the standard Gaussian measure
Emanuel Milman
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Finite deficiency indices and uniform remainder in Weyl's law [PDF]
, 2010 We give a proof that in settings where Von Neumann deficiency indices are finite the spectral counting functions of two different self-adjoint extensions of the same symmetric operator differ by a uniformly bounded term (see also Birman-Solomjak's ...
Hillairet, Luc
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Self-Adjointness of Dirac Operators with Infinite Mass Boundary Conditions in Sectors
, 2018 This paper deals with the study of the two-dimensional Dirac operatorwith infinite mass boundary condition in a sector. We investigate the question ofself-adjointness depending on the aperture of the sector: when the sector is convexit is self-adjoint on
Ourmières-Bonafos, Thomas +1 more
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Hybrid Reaction–Diffusion Epidemic Models: Dynamics and Emergence of Oscillations
Mathematical Methods in the Applied Sciences, Volume 49, Issue 5, Page 4074-4095, 30 March 2026.ABSTRACT In this paper, we construct a hybrid epidemic mathematical model based on a reaction–diffusion system of the SIR (susceptible‐infected‐recovered) type. This model integrates the impact of random factors on the transmission rate of infectious diseases, represented by a probabilistic process acting at discrete time steps.
Asmae Tajani +2 more
wiley +1 more source
Coupling of symmetric operators and the third Green identity
Bulletin of Mathematical Sciences, 2017 The principal aim of this paper is to derive an abstract form of the third Green identity associated with a proper extension T of a symmetric operator S in a Hilbert space $$\mathfrak {H}$$ H , employing the technique of quasi boundary triples for T. The
Jussi Behrndt +3 more
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