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We study the Cauchy problem for a class of linear evolution equations of arbitrary order with coefficients depending both on time and space variables. Under suitable decay assumptions on the coefficients of the lower order terms for $|x|$…

Analysis of PDEs · Mathematics 2025-04-07 Alexandre Arias Junior , Alessia Ascanelli , Marco Cappiello , Eliakim Cleyton Machado

We propose a variant of Cauchy's Lemma, proving that when a convex chain on one sphere is redrawn (with the same lengths and angles) on a larger sphere, the distance between its endpoints increases. The main focus of this work is a…

We develop a new method to determine the acceleration of a block sliding down along the face of a moving wedge. We have been able to link the solution of this problem to that of the inclined plane problem of elementary physics, thus…

Physics Education · Physics 2009-10-31 Oscar Bolina , J. R. Parreira

We prove the existence of locally distance increasing maps with it controllable small curvatures

Differential Geometry · Mathematics 2023-07-10 Misha Gromov

We prove that for any knot $K$, there exists a one-vertex triangulation of the $3$-sphere containing an edge forming $K$. The proof is constructive, and based on fully augmented links. We use our method to produce ``complicated'' simplicial…

Geometric Topology · Mathematics 2024-12-02 Dionne Ibarra , Daniel V. Mathews , Jessica S. Purcell , Jonathan Spreer

In this note we prove convexity, in the sense of Colding-Naber, of the regular set of solutions to some complex Monge-Ampere equations with conical singularities along simple normal crossing divisors. In particular, any two points in the…

Differential Geometry · Mathematics 2014-07-07 Ved V. Datar

We address several specific aspects of the following general question: can a field K have so many automorphisms that the action of the automorphism group on the elements of K has relatively few orbits? We prove that any field which has only…

Commutative Algebra · Mathematics 2007-05-23 Kiran S. Kedlaya , Bjorn Poonen

We study when an arrangement of axis-aligned rectangles can be transformed into an arrangement of axis-aligned squares in $\mathbb{R}^2$ while preserving its structure. We found a counterexample to the conjecture of J. Klawitter, M.…

Computational Geometry · Computer Science 2016-11-24 Matěj Konečný , Stanislav Kučera , Michal Opler , Jakub Sosnovec , Štěpán Šimsa , Martin Töpfer

The aim of this paper is to generalize some fixed point theorems in the class of convex contraction of order $m$ on a complete suprametric space. Then, we will prove that the class of convex contraction of order m is strong enough to…

General Mathematics · Mathematics 2026-05-11 Nicola Fabiano , Sedigheh Barootkoob , Hossein Lakzian

In this paper we obtain explicit lower bounds for the radius of convergence of the Painlev\'e expansions of the Korteweg-de-Vries equation around a movable singularity manifold ${\Cal S}$ in terms of the sup norms of the arbitrary functions…

solv-int · Physics 2009-10-30 Nalini Joshi , Gopala K. Srinivasan

Metrizable spaces are studied in which every closed set is an $\alpha$-limit set for some continuous map and some point. It is shown that this property is enjoyed by every space containing sufficiently many arcs (formalized in the notion of…

Dynamical Systems · Mathematics 2022-02-14 Jana Hantáková , Samuel Roth , Ľubomír Snoha

We construct a union of N parallelograms of dimensions approximately 1/N x 1 in the plane, with the slope of their long sides in the standard Cantor set. The union has area 1/log N but the union of the doubles has area log log N/ log N. In…

Classical Analysis and ODEs · Mathematics 2007-05-23 Michael D. Bateman , Nets Hawk Katz

We construct a Banach space satisfying that the nearest point map (also called proximity mapping or metric projection) onto any compact and convex subset is continuous but not uniformly continuous. The space we construct is locally…

Functional Analysis · Mathematics 2024-02-08 Rubén Medina , Andrés Quilis

We show that under Space Curve Shortening flow any closed immersed curve in $\mathbb R^n$ whose projection onto $\mathbb{R}^2\times\{\vec{0}\}$ is convex remains smooth until it shrinks to a point. Throughout its evolution, the projection…

Differential Geometry · Mathematics 2024-10-29 Qi Sun

We show that a set is almost periodic if and only if the associated exponential sum is concentrated in the minor arcs. Hence binary additive problems involving almost periodic sets can be solved using the circle method.

Number Theory · Mathematics 2011-05-10 Jan-Christoph Schlage-Puchta

Four alternative proposals as the possible solutions for the rotation curve problem are introduced on the basis of assumption that the cosmic expansion is engaged with the galactic dynamics over the halo. The first one proposes a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 F. Darabi

Sweeping is a commonly used procedure to explicitly solve the discrete ordinates equation, which itself is a common approximation of the neutron transport equation. To sweep through the computational domain, an ordering of the spatial cells…

Numerical Analysis · Mathematics 2018-06-22 Thomas Camminady , Martin Frank

We show that every minimum area isosceles triangle containing a given triangle $T$ shares a side and an angle with $T$. This proves a conjecture of Nandakumar motivated by a computational problem. We use our result to deduce that for every…

Metric Geometry · Mathematics 2020-09-04 Gergely Kiss , János Pach , Gábor Somlai

We discover some very general configuration results for constructing area-minimizing cones. In particular, given any closed minimal submanifold in some Euclidean sphere, every cone over the minimal product of sufficiently many copies of the…

Differential Geometry · Mathematics 2026-02-27 Yongsheng Zhang

Motivated by problems arising in the relative trace formula and arithmetic invariant theory we prove the existence of rational points on orbits arising from certain infinitesimal symmetric spaces. As an application, we prove analogous…

Number Theory · Mathematics 2019-03-05 Trung Can , Chung-Ru Lee , Benjamin Nativi , Gary Zhou