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This paper is devoted to self-adjoint cyclically compact operators on Hilbert--Kaplansky module over a ring of bounded measurable functions. The spectral theorem for such a class of operators are given. We apply this result to partial…

Operator Algebras · Mathematics 2015-02-10 Farrukh Mukhamedov , Karimbergen Kudaybergenov

Let $L$ be a one-to-one operator of type $\omega$ having a bounded $H_\infty$ functional calculus and satisfying the $k$-Davies-Gaffney estimates with $k\in{\mathbb N}$. In this paper, the authors introduce the weak Hardy space…

Classical Analysis and ODEs · Mathematics 2014-12-02 Jun Cao , Der-Chen Chang , Huoxiong Wu , Dachun Yang

In this paper we are concerned with a homogeneous differential operator $p$ of order $m$ of which characteristic set of order $m$ is assumed to be a smooth manifold. We define the Gevrey strong hyperbolicity index as the largest number $s$…

Analysis of PDEs · Mathematics 2016-04-29 Tatsuo Nishitani

In this paper we study harmonic analysis operators in Dunkl settings associated with finite reflection groups on Euclidean spaces. We consider maximal operators, Littlewood-Paley functions, $\rho$-variation and oscillation operators…

Classical Analysis and ODEs · Mathematics 2023-09-13 Víctor Almeida , Jorge J. Betancor , Juan C. Fariña , Lourdes Rodríguez-Mesa

We study the motion of smooth, closed, strictly convex hypersurfaces in $\mathbb{R}^{n+1}$ expanding in the direction of their normal vector field with speed depending on the $k$th elementary symmetric polynomial of the principal radii of…

Analysis of PDEs · Mathematics 2025-06-30 Mohammad N. Ivaki

Let $\Sigma_k(p)$ be the class of univalent meromorphic functions defined on $\mathbb{D}$ with $k$-quasiconformal extension to the extended complex plane $\widehat{\mathbb{C}}$, where $0\leq k < 1$. Let $\Sigma_k^0(p)$ be the class of…

Complex Variables · Mathematics 2017-11-27 Bappaditya Bhowmik , Goutam Satpati

Let M\"{o}b denote the group of biholomorphic automorphisms of the unit disc and $(\mbox{M\"{o}b} \cdot T)$ be the orbit of a Hilbert space operator $T$ under the action of M\"{o}b. If the quotient $(\mbox{M\"{o}b} \cdot T)/\sim$, where…

Functional Analysis · Mathematics 2018-11-14 Soumitra Ghara

The discrete Laplace operator is ubiquitous in spectral shape analysis, since its eigenfunctions are provably optimal in representing smooth functions defined on the surface of the shape. Indeed, subspaces defined by its eigenfunctions have…

Computer Vision and Pattern Recognition · Computer Science 2018-05-15 Yoni Choukroun , Gautam Pai , Ron Kimmel

This paper studies the Cauchy problem for variable coefficient weakly hyperbolic first order systems of partial differential operators. The hyperbolicity assumption is that for each $t, x$ the principal symbol is hyperbolic. No hypothesis…

Analysis of PDEs · Mathematics 2019-11-07 Ferruccio Colombini , Tatsuo Nishitani , Jeffrey Rauch

In this paper we investigate the spectra and the ergodic properties of the multiplication operators and the convolution operators acting on the Schwartz space $\mathcal{S}(\mathbb{R})$ of rapidly decreasing functions, i.e., operators of the…

Functional Analysis · Mathematics 2021-03-25 Angela A. Albanese , Claudio Mele

Given a graded group $G$ and commuting, formally self-adjoint, left-invariant, homogeneous differential operators $\mathcal{L}_1,\dots, \mathcal{L}_n$ on $G$, one of which is Rockland, we study the convolution operators…

Functional Analysis · Mathematics 2019-07-16 Mattia Calzi

In quantum theory on curved backgrounds, Heisenberg's uncertainty principle is usually discussed in terms of ensemble variances and flat-space commutators. Here we take a different, preparation-based viewpoint tailored to sharp position…

General Relativity and Quantum Cosmology · Physics 2026-02-05 Thomas Schürmann

Smoothing a signal based on local neighborhoods is a core operation in machine learning and geometry processing. On well-structured domains such as vector spaces and manifolds, the Laplace operator derived from differential geometry offers…

Computer Vision and Pattern Recognition · Computer Science 2025-07-09 Nathan Kessler , Robin Magnet , Jean Feydy

The aim of this paper is to get the boundedness of certain sublinear operators with rough kernel generated by Calder\'on-Zygmund operators on the generalized weighted Morrey spaces under generic size conditions which are satisfied by most…

Functional Analysis · Mathematics 2016-07-01 Ferit Gurbuz

We prove that if u is a bounded smooth function in the kernel of a nonnegative Schrodinger operator $-L=-(\Delta +q)$ on a parabolic Riemannian manifold M, then u is either identically zero or it has no zeros on M, and the linear space of…

Differential Geometry · Mathematics 2014-11-25 Jose M. Manzano , Joaquin Perez , M. Magdalena Rodriguez

We provide a precise description of the bottom of the spectrum in the semiclassical limit of a harmonic-type Schr\"odinger operator with an inverse square potential. By exploiting the connection between the eigenfunctions of these operators…

Spectral Theory · Mathematics 2026-04-13 Roman Vanlaere

We consider an elliptic self-adjoint first order pseudodifferential operator acting on columns of complex-valued half-densities over a connected compact manifold without boundary. The eigenvalues of the principal symbol are assumed to be…

Spectral Theory · Mathematics 2013-06-12 Olga Chervova , Robert J. Downes , Dmitri Vassiliev

We study closed orientable surfaces satisfying the spectral condition $\lambda_1(-\Delta+\beta K)\geq\lambda\geq0$, where $\beta$ is a positive constant and $K$ is the Gauss curvature. This condition naturally arises for stable minimal…

Differential Geometry · Mathematics 2023-03-20 Kai Xu

Hermitian monogenic functions are the null solutions of two complex Dirac type operators. The system of these complex Dirac operators is overdetermined and may be reduced to constraints for the Cauchy datum together with what we called the…

Complex Variables · Mathematics 2016-01-25 Fabrizio Colombo , Dixan Peña Peña , Frank Sommen

We develop the concept of integral Menger curvature for a large class of nonsmooth surfaces. We prove uniform Ahlfors regularity and a $C^{1,\lambda}$-a-priori bound for surfaces for which this functional is finite. In fact, it turns out…

Classical Analysis and ODEs · Mathematics 2010-12-16 Pawel Strzelecki , Heiko von der Mosel