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We consider a functional calculus for compact operators, acting on the singular values rather than the spectrum, which appears frequently in applied mathematics. Necessary and sufficient conditions for this singular value functional…

Functional Analysis · Mathematics 2016-11-14 Fredrik Andersson , Marcus Carlsson , Karl-Mikael Perfekt

Given a holomorphic regularisation procedure (e.g. Riesz or dimensional regularisation) on classical symbols, we define renormalised multiple integrals of radial classical symbols with linear constraints. To do so, we first prove the…

Mathematical Physics · Physics 2008-03-12 Sylvie Paycha

Let $H(D)$ denote the space of holomorphic functions on the unit disk $D$. We characterize those radial weights $w$ on $D$, for which there exist functions $f, g \in H(D)$ such that the sum $|f| + |g|$ is equivalent to $w$. Also, we obtain…

Complex Variables · Mathematics 2021-08-20 Evgeny Abakumov , Evgueni Doubtsov

We construct a homeomorphism between the compact regular locale of integrals on a Riesz space and the locale of (valuations) on its spectrum. In fact, we construct two geometric theories and show that they are biinterpretable. The…

Logic · Mathematics 2009-04-01 Thierry Coquand , Bas Spitters

This current article aims to study a new subclass of meromorphic functions with positive coefficients by reconstructing a new operator in the punctured open disc. Also, some geometric properties are considered and investigated, such results…

Complex Variables · Mathematics 2024-08-16 Ali H. Maran , Abdul Rahman S. Juma , Raheam A. Al-Saphory

A recurring task in particle physics and statistics is to compute the complex critical points of a product of powers of affine-linear functions. The logarithmic discriminant characterizes exponents for which such a function has a degenerate…

Algebraic Geometry · Mathematics 2025-06-09 Leonie Kayser , Andreas Kretschmer , Simon Telen

We study the mixed-integer epigraph of a special class of convex functions with non-convex indicator constraints, which are often used to impose logical constraints on the support of the solutions. The class of functions we consider are…

Optimization and Control · Mathematics 2023-09-19 Shaoning Han , Andrés Gómez

We study pluricomplex Green functions on algebraic sets. Let $f$ be a proper holomorphic mapping between two algebraic sets. Given a compact set $K$ in the range of $f$, we show how to estimate the pluricomplex Green functions of $K$ and of…

Complex Variables · Mathematics 2023-07-26 Leokadia Bialas-Ciez , Maciej Klimek

The Fueter-Sce-Qian mapping theorem is a two steps procedure to extend holomorphic functions of one complex variable to quaternionic or Clifford algebra-valued functions in the kernel of a suitable generalized Cauchy-Riemann operator. Using…

Complex Variables · Mathematics 2021-12-10 Fabrizio Colombo , Antonino De Martino , Irene Sabadini

An odd meromorphic function f(s) is constructed from the Riemann zeta-function evaluated at one-half plus s. The partial fraction expansion, p(s), of f(s) is obtained using the conjunction of the Riemann hypothesis and hypotheses advanced…

General Mathematics · Mathematics 2007-05-23 Anthony Csizmazia

A weak and a strong concept of plurifinely plurisubharmonic and plurifinely holomorphic functions are introduced. Strong will imply weak. The weak concept is studied further. A function f is weakly plurifinely plurisubharmonic if and only…

Complex Variables · Mathematics 2010-11-22 Mohamed El Kadiri , Bent Fuglede , Jan Wiegerinck

The growth of meromorphic solutions of linear difference equations containing Askey-Wilson divided difference operators is estimated. The $\varphi$-order is used as a general growth indicator, which covers the growth spectrum between the…

Complex Variables · Mathematics 2021-01-29 Hui Yu , Janne Heittokangas , Jun Wang , Zhi-Tao Wen

In this paper we extend the $H^\infty$ functional calculus to quaternionic operators and to $n$-tuples of noncommuting operators using the theory of slice hyperholomorphic functions and the associated functional calculus, called…

Functional Analysis · Mathematics 2015-11-25 D. Alpay , F. Colombo , T. Qian , I. Sabadini

We show for a certain class of operators $A$ and holomorphic functions $f$ that the functional calculus $A\mapsto f(A)$ is holomorphic. Using this result we are able to prove that fractional Laplacians $(1+\Delta^g)^p$ depend real…

Differential Geometry · Mathematics 2023-12-08 Martin Bauer , Martins Bruveris , Philipp Harms , Peter W. Michor

We use functions of a bicomplex variable to unify the existing constructions of harmonic morphisms from a 3-dimensional Euclidean or pseudo-Euclidean space to a Riemannian or Lorentzian surface. This is done by using the notion of…

Differential Geometry · Mathematics 2010-03-12 Paul Baird , John C. Wood

Given a multivariate complex polynomial ${p\in\mathbb{C}[z_1,\ldots,z_n]}$, the imaginary projection $\mathcal{I}(p)$ of $p$ is defined as the projection of the variety $\mathcal{V}(p)$ onto its imaginary part. We focus on studying the…

Algebraic Geometry · Mathematics 2022-11-02 Stephan Gardoll , Mahsa Sayyary Namin , Thorsten Theobald

We prove some sharp inequalities for complex harmonic functions on the unit disk. The results extend a M. Riesz conjugate function theorem and some well-known estimates for holomorphic functions. We apply some of results to the…

Complex Variables · Mathematics 2017-01-20 David Kalaj

In the first part we show that a vector-valued almost separably valued function $f$ is holomorphic (harmonic) if and only if it is dominated by an $L^1_\mathrm{loc}$ function and there exists a separating set $W\subset X'$ such that…

Functional Analysis · Mathematics 2020-10-21 Wolfgang Arendt , Manuel Bernhard , Marcel Kreuter

Given a nonconstant holomorphic map f: X -> Y between compact Riemann surfaces, one of the first objects we learn to construct is its ramification divisor R_f, which describes the locus at which f fails to be locally injective. The divisor…

Number Theory · Mathematics 2013-02-21 Xander Faber

The Morse-Smale complex of a function $f$ decomposes the sample space into cells where $f$ is increasing or decreasing. When applied to nonparametric density estimation and regression, it provides a way to represent, visualize, and compare…

Statistics Theory · Mathematics 2017-04-05 Yen-Chi Chen , Christopher R. Genovese , Larry Wasserman