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Related papers: On the Differentiability of Quaternion Functions

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In this paper we presents an algorithm for finding a solution of the linear nonhomogeneous quaternionic-valued differential equations. Moveover, several examples shows the feasibility of our algorithm.

Classical Analysis and ODEs · Mathematics 2022-02-15 Yong-Hui Xia , Hai Huang , Kit Ian Kou

This paper builds on the notion of the so-called orthogonal derivative, where an n-th order derivative is approximated by an integral involving an orthogonal polynomial of degree n. This notion was reviewed in great detail in a paper in J.…

Classical Analysis and ODEs · Mathematics 2014-07-08 E. Diekema

We begin with an improvement to an extension result for subharmonic functions of Blanchet et al. With the aid of this improvement we then give extension results for subharmonic functions, for separately subharmonic functions, for harmonic…

Analysis of PDEs · Mathematics 2019-07-22 Juhani Riihentaus

We develop Cresson's nondifferentiable calculus of variations on the space of H\"{o}lder functions. Several quantum variational problems are considered: with and without constraints, with one and more than one independent variable, of first…

Optimization and Control · Mathematics 2011-11-29 Ricardo Almeida , Delfim F. M. Torres

The main purpose in the present paper is to build a Hamiltonian theory for fields which is consistent with the principles of relativity. For this we consider detailed geometric pictures of Lepage theories in the spirit of Dedecker and try…

Mathematical Physics · Physics 2007-05-23 Frédéric Hélein , Joseph Kouneiher

In this study, we introduce the concept of commutative quaternions and commutative quaternion matrices. Firstly, we give some properties of commutative quaternions and their Hamilton matrices. After that we investigate commutative…

Algebraic Geometry · Mathematics 2016-11-26 Hidayet Hüda Kösal , Murat Tosun

We consider a length functional for $C^1$ curves of fixed degree in graded manifolds equipped with a Riemannian metric. The first variation of this length functional can be computed only if the curve can be deformed in a suitable sense, and…

Metric Geometry · Mathematics 2021-10-14 Giovanna Citti , Gianmarco Giovannardi , Manuel Ritoré

We obtain several Euler-Lagrange equations for variational functionals defined on a set of H\"older curves. The cases when the Lagrangian contains multiple scale derivatives, depends on a parameter, or contains higher-order scale…

Mathematical Physics · Physics 2010-06-01 Ricardo Almeida , Delfim F. M. Torres

Hypergeometric class equations are given by second order differential operators in one variable whose coefficient at the second derivative is a polynomial of degree $\leq2$, at the first derivative of degree $\leq1$ and the free term is a…

Classical Analysis and ODEs · Mathematics 2025-07-08 Jan Dereziński

The aim of this work is to study fiber derivatives associated to Lagrangian and Hamiltonian functions describing the dynamics of a higher-order autonomous dynamical system. More precisely, given a function in $T^*T^{(k-1)}Q$, we find…

Mathematical Physics · Physics 2021-01-29 Leonardo Colombo , Pedro D. Prieto-Martínez

A derivative expansion technique is developed to compute functional determinants of quadratic operators, non diagonal in spacetime indices. This kind of operators arise in general 't Hooft gauge fixed Lagrangians. Elaborate applications of…

High Energy Physics - Theory · Physics 2009-10-31 Vasilios Zarikas

This paper is an introduction to the theory of multivector functions of a real variable. The notions of limit, continuity and derivative for these objects are given. The theory of multivector functions of a real variable, even being similar…

General Mathematics · Mathematics 2016-08-16 A. M. Moya , V. V. Fernández , W. A. Rodrigues

In this article one introduces a formalism of classical mechanics where complex Lagrangian functions are admitted. The results include complex versions of the Lagrangian function, of the Euler-Lagrange equation, of the Hamilton principle, a…

Mathematical Physics · Physics 2026-02-03 Sergio Giardino

We review the theory of derivators from the ground up, defining new classes of derivators which were originally motivated by derivator K-theory. We prove that many old arguments that relied on homotopical bicompleteness hold also for…

K-Theory and Homology · Mathematics 2022-04-05 Ian Coley

In this paper we find fractional Riemann-Liouville derivatives for the Takagi-Landsberg functions. Moreover, we introduce their generalizations called weighted Takagi-Landsberg functions which have arbitrary bounded coefficients in the…

Classical Analysis and ODEs · Mathematics 2020-03-31 Vitalii Makogin , Yuliya Mishura

With the modified Riemann-Liouville fractional derivative, a fractional Tu formula is presented to investigate generalized Hamilton structure of fractional soliton equations. The obtained results can be reduced to the classical Hamilton…

Exactly Solvable and Integrable Systems · Physics 2015-05-20 Guo-cheng Wu , Sheng Zhang

If a higher derivative theory arises from a transformation of variables that involves time derivatives, a tailor-made Hamiltonian formulation is shown to exist. The details and advantages of this elegant Hamiltonian formulation, which…

Mathematical Physics · Physics 2019-06-05 Hans Christian Öttinger

Humbert confluent hypergeometric functions of two variables arise in many problems of mathematical physics and applied analysis, yet their behavior with respect to parameters has not been systematically studied. In this paper we investigate…

Classical Analysis and ODEs · Mathematics 2025-12-16 Ayman Shehata , Recep Sahin , Oguz Yagcı , Shimaa I. Moustafa

The paper studies the complex differentiable functions of double argument and their properties, which are similar to the properties of the holomorphic functions of complex variable: the Cauchy formula, the hyperbolic harmonicity, the…

General Mathematics · Mathematics 2015-01-14 Dmitry Pavlov , Sergey Kokarev

In this paper, we present a new class of operators, which we name to be $n$-Ritt operators. This produces a discrete analogue of $n$-sectorial operators and generalizes the notion of Ritt operators. We develop a $H^\infty$-functional…

Functional Analysis · Mathematics 2017-09-19 Samya Kumar Ray