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We combine several folklore observations to provide a working framework for iterating constructions which contradict the axiom of choice. We use this to define a model in which any kind of structural failure must fail with a proper class of…

Logic · Mathematics 2021-07-26 Asaf Karagila

A method to construct trihamiltonian extensions of a separable system is presented. The procedure is tested for systems, with a natural Hamiltonian, separable in classical sense in one of the four orthogonal separable coordinate systems of…

Exactly Solvable and Integrable Systems · Physics 2007-05-23 Luca Degiovanni

This work introduces a Hamiltonian approach to regularization and linearization of central-force particle dynamics through a new canonical extension of the so-called "projective decomposition". The regularization scheme is formulated within…

Dynamical Systems · Mathematics 2026-02-02 Joseph T. A. Peterson , Manoranjan Majji , John L. Junkins

This paper addresses the problem of determining the symmetries of a plane or space curve defined by a rational parametrization. We provide effective methods to compute the involution and rotation symmetries for the planar case. As for space…

Algebraic Geometry · Mathematics 2014-05-13 J. G. Alcázar , C. Hermoso , G. Muntingh

In \cite{Sz25} we generalized the famous Menelaus' and Ceva's theorems for translation triangles in each non-constant curvature Thurston geometry. In this paper based on the described method and results, we prove that the classical…

Metric Geometry · Mathematics 2026-03-03 Jenő Szirmai

Latent-space optimization methods for counterfactual explanations - framed as minimal semantic perturbations that change model predictions - inherit the ambiguity of Wachter et al.'s objective: the choice of distance metric dictates whether…

Machine Learning · Computer Science 2026-03-03 Eslam Zaher , Maciej Trzaskowski , Quan Nguyen , Fred Roosta

An important result in real algebraic geometry is the projection theorem: every projection of a semialgebraic set is again semialgebraic. This theorem and some of its conclusions lie at the basis of many other results, for example the…

Functional Analysis · Mathematics 2017-09-26 Tom Drescher , Tim Netzer , Andreas Thom

Given a compact set K in the plane, which contains no triple of points forming a vertical and a horizontal segment, and a continuous real-valued map f on K, we give a construction of real-valued continuous maps of one variable g,h such that…

General Topology · Mathematics 2007-05-23 Eva Trenklerova

Structured prediction provides a general framework to deal with supervised problems where the outputs have semantically rich structure. While classical approaches consider finite, albeit potentially huge, output spaces, in this paper we…

Machine Learning · Statistics 2018-06-27 Alessandro Rudi , Carlo Ciliberto , Gian Maria Marconi , Lorenzo Rosasco

Constructivists (and intuitionists in general) asked what kind of mental construction is needed to convince ourselves (and others) that some mathematical statement is true. This question has a much more practical (and even cynical)…

History and Overview · Mathematics 2023-06-01 Alexander Shen

We study a conservative extension of classical propositional logic distinguishing between four modes of statement: a proposition may be affirmed or denied, and it may be strong or classical. Proofs of strong propositions must be…

Logic in Computer Science · Computer Science 2021-04-19 Pablo Barenbaum , Teodoro Freund

We discover a simple construction of a four-dimensional family of smooth surfaces of general type with $p_g(S)=q(S)=0$, $K^2_S=3$ with cyclic fundamental group $C_{14}$. We use a degeneration of the surfaces in this family to find…

Algebraic Geometry · Mathematics 2020-04-23 Lev Borisov , Enrico Fatighenti

A classical approach to investigate a closed projective scheme $W$ consists of considering a general hyperplane section of $W$, which inherits many properties of $W$. The inverse problem that consists in finding a scheme $W$ starting from a…

Algebraic Geometry · Mathematics 2018-07-20 Cristina Bertone , Francesca Cioffi , Davide Franco

Using an elementary argument, we prove new fixed point theorems for classical elliptic complexes. We obtain new results for conformal relations and coisotropic intersections. We obtain theorems for the average intersections of families of…

Differential Geometry · Mathematics 2007-05-23 Mark Stern

There is a parallelism between growth in arithmetic combinatorics and growth in a geometric context. While, over $\mathbb{R}$ or $\mathbb{C}$, geometric statements on growth often have geometric proofs, what little is known over finite…

Combinatorics · Mathematics 2012-12-21 Nick Gill , H. A. Helfgott , Misha Rudnev

The real numbers are important in both mathematics and computation theory. Computationally, real numbers can be represented in several ways; most commonly using inexact floating-point data-types, but also using exact arbitrary-precision…

Logic in Computer Science · Computer Science 2024-01-18 Todd Waugh Ambridge

The rigorous tools of convex analysis are used to examine various serial and parallel combinations of linear viscosity and perfect plasticity. Nonlinear viscosities are also considered. The general aim is to synthesize a single convex…

Mathematical Physics · Physics 2026-04-20 Tomáš Roubíček

In this note we study curves (arrangements) in the complex projective plane which can be considered as generalizations of free curves. We construct families of arrangements which are nearly free and possess interesting geometric properties.…

Algebraic Geometry · Mathematics 2021-09-22 Grzegorz Malara , Piotr Pokora , Halszka Tutaj-Gasińska

The constructive approach to mathematics has the advantage that witnesses can be extracted from statements of existence and theorems can be unwound to give algorithms. Even better, constructive theorems can be interpreted in any topos,…

General Topology · Mathematics 2024-11-26 Graham Manuell

This paper deals with certain fundamental results about affine hulls and simplices in a real normed linear space. The framework of the paper is Bishop's constructive mathematics, which, with its characteristic interpretation of existence as…

Logic · Mathematics 2025-09-26 Douglas S. Bridges