English
Related papers

Related papers: Another Proof of Darboux's Theorem

200 papers

We prove the Bloch-Ogus Theorem for regular local rings geometrically regular over a discrete valuation ring. In particular, we prove the Bloch-Ogus Theorem for regular local rings of mixed characteristic that are essentially smooth over a…

Algebraic Geometry · Mathematics 2026-03-31 Ivan Gaidai-Turlov

We consider a functional being a difference of two differentiable convex functionals on a closed ball. Existence and multiplicity of critical points is investigated. Some applications are given.

Classical Analysis and ODEs · Mathematics 2015-03-25 Marek Galewski

The mean value theorem of calculus states that, given a differentiable function $f$ on an interval $[a, b]$, there exists at least one mean value abscissa $c$ such that the slope of the tangent line at $c$ is equal to the slope of the…

Classical Analysis and ODEs · Mathematics 2025-07-28 David Lowry-Duda , Miles H. Wheeler

We consider equations that represent a constancy condition for a 2D Wronskian, mixed Wronskian-Casoratian and 2D Casoratian. These determinantal equations are shown to have the number of independent integrals equal to their order - this…

Exactly Solvable and Integrable Systems · Physics 2014-11-24 Dmitry K. Demskoi , Dinh T. Tran

We develop the Darboux procedure for the case of the two-level system. In particular, it is demonstrated that one can construct the Darboux intertwining operator that does not violate the specific structure of the equations of the two-level…

Mathematical Physics · Physics 2007-05-23 V. G. Bagrov , M. C. Baldiotti , D. M. Gitman , V. V. Shamshutdinova

The Aldous-Hoover Theorem concerns an infinite matrix of random variables whose distribution is invariant under finite permutations of rows and columns. It states that, up to equality in distribution, each random variable in the matrix can…

Statistics Theory · Mathematics 2025-11-26 Leihao Chen , Tobias Fritz , Tomáš Gonda , Andreas Klingler , Antonio Lorenzin

A new form of a binary Darboux transformation is used to generate analytical solutions of a nonlinear Liouville-von Neumann equation. General theory is illustrated by explicit examples.

Quantum Physics · Physics 2009-10-31 Sergei B. Leble , Marek Czachor

We introduce a notion of a noncommutative function defined on a domain of $d$-tuples of bounded operators on an infinite dimensional Hilbert space. Inverse and implicit function theorems in this setting are established. When these…

Functional Analysis · Mathematics 2021-08-25 Mark E. Mancuso

In this paper, we introduce a new generalized derivative, which we term the specular derivative. We establish the Quasi-Rolles' Theorem, the Quasi-Mean Value Theorem, and the Fundamental Theorem of Calculus in light of the specular…

Classical Analysis and ODEs · Mathematics 2025-12-30 Kiyuob Jung , Jehan Oh

We show in a rigorous way that Crum's result on equal eigenvalue spectrum of Sturm-Liouville problems can be obtained iteratively by successive Darboux transformations. It can be shown that all neighbouring Darboux-transformed potentials of…

Mathematical Physics · Physics 2008-11-26 Jose Orlando Organista , M. Nowakowski , H. C. Rosu

The Brouwer fixed point theorem says that any continuous function from disc to itself has a fixed point. By using simple geometrical technique we have generalized the result in manifold and proved that any continuous function on the…

Differential Geometry · Mathematics 2020-08-04 Absos Ali Shaikh , Chandan Kumar Mondal

This survey revisits classical results in vector calculus and analysis by exploring a generalised perspective on the exterior derivative, interpreting it as a measure of "infinitesimal flux". This viewpoint leads to a higher-dimensional…

Differential Geometry · Mathematics 2026-03-25 Daniel Fadel , Henrique N. Sá Earp , Tomás S. R. Silva

Let F = F_p for any fixed prime p >= 2. An affine-invariant property is a property of functions on F^n that is closed under taking affine transformations of the domain. We prove that all affine-invariant property having local…

Computational Complexity · Computer Science 2013-01-18 Arnab Bhattacharyya , Eldar Fischer , Hamed Hatami , Pooya Hatami , Shachar Lovett

Let $X$ and $Y$ be Banach or normed linear spaces and $F\subset X$ a closed set. We apply our recent extension theorem for vector-valued Baire one functions arXiv:1512.03717 to obtain an extension theorem for vector-valued functions…

Classical Analysis and ODEs · Mathematics 2017-01-24 Martin Koc , Jan Kolář

The first part of the present article consists in a survey about the dynamical constructive method designed using dynamical theories and dynamical algebraic structures. Dynamical methods uncovers a hidden computational content for numerous…

Algebraic Geometry · Mathematics 2023-09-06 Henri Lombardi , Assia Mahboubi

We consider a discrete equation, defined on the two-dimensional square lattice, which is linearizable, namely, of the Burgers type and depends on a parameter $\alpha$. For any natural number $N$ we choose $\alpha$ so that the equation…

Exactly Solvable and Integrable Systems · Physics 2012-07-13 Rustem N. Garifullin , Ravil I. Yamilov

In this paper, we show by a counterexample that the gH-partial derivative of interval-valued functions (IVFs) may exist even when the partial derivative of the end point functions do not. Next, we introduce the gH-partial derivative in…

Optimization and Control · Mathematics 2025-09-10 Amir Suhail , Tauheed , Akhlad Iqbal

In this paper, we develop discrete versions of Darboux transformations and Crum's theorems for two second order difference equations. The difference equations are discretised versions (using Darboux transformations) of the spectral problems…

Exactly Solvable and Integrable Systems · Physics 2018-03-13 Cheng Zhang , Linyu Peng , Da-jun Zhang

This work reviews the classical Darboux theorem for symplectic, presymplectic, and cosymplectic manifolds (which are used to describe regular and singular mechanical systems), and certain cases of multisymplectic manifolds, and extends it…

Differential Geometry · Mathematics 2023-07-10 Xavier Gràcia , Javier de Lucas , Xavier Rivas , Narciso Román-Roy

The paper gives a unified and simple proof of both theorems and Cousin's theorem.

History and Overview · Mathematics 2022-09-27 Claude-Alain Faure