?
A dynamical system in the space of convex quadrangles
Let us consider a family F(alpha,beta,gamma,delta) of convex quadrangles in the plane with given angles
{alpha,beta,gamma,delta} and with the perimeter 2pi. Such quadrangle Q from F(alpha,beta,gamma,delta) can be
considered as a point (x_1,x_2,x_3,x_4) in 4-dimensional space R^4, where {x_1,x_2,x_3,x_4} --- lengths of edges. Then to F a finite open segment I in R^4 is corresponded. A quadrangle in F, that corresponds to the midpoint of I$is called a balanced quadrangle. Let M be the set of balanced quadrangles. The function f:M -- > M is defined in the following way: angles of the balanced quadrangle Q', Q'=f(Q), are numerically equal to edges of Q. The map f defines a dynamical system in the space of balanced quadrangles. In this work we study properties of this system.
Levashev V., / Series arXiv "math". 2026. No. 2609.06010.
We prove that continuous A-bilinear pairings on the ring of Laurent series that are invariant under continuous automorphisms coincide, up to a constant, with the pairing given by the residue of a differential form over any commutative associative ring with identity. ...
Added: September 24, 2026
Pyatov P. N., Pivovarov P. A., / Series math "arxiv.org". 2026. No. 2609.06274.
We investigate a special ansats that allows for an iterative solution of the constant Yang-Baxter equation. Testing this ansatz, we construct four sequences of the constant R-matrices. In each sequence the R-matrices act on the tensor squares of vector spaces of linearly growing dimensions. Each R-matrix also depends on a single complex parameter.
By analyzing the ...
Added: September 24, 2026
Medvedev V., / Series arXiv "math". 2026.
We study complete static manifolds with boundary admitting a nowhere-vanishing static potential. Our main result shows that, under a natural lower bound relating the scalar curvature and the boundary mean curvature, a simple static manifold with boundary must in fact have positive scalar curvature, negative boundary mean curvature, and be compact; we also obtain explicit ...
Added: September 19, 2026
Letellier C., Nataliya Stankevich, Houri S. et al., Chaos 2026 Vol. 36 No. 9 Article 093128
Toroidal chaos designates a chaotic solution that is structured in the neighborhood of a torus. For being chaotic, such a torus needs to be discontinuously fractalized to present a Cantor set, ensuring the great sensitivity to initial conditions required for chaos. A fractal is related to self-similarity and a non-integer dimension. In fact, although clearly ...
Added: September 16, 2026
Poddiakov A., / Series Social Science Research Network "Social Science Research Network". 2026. No. 7437658.
Clarity of knowledge and reasoning is necessary in many cases. Yet vagueness in scientific thinking related to surprise, curiosity, "ability to engage with not-knowing" (de Freitas) and abductive reasoning is also a crucially important source of scientific creativity which supplements combinatorial logic when dealing with the already known. Starting from studies by C. S. Peirce ...
Added: September 15, 2026
Glutsyuk A., / Series arXiv "math". 2026.
B.Josephson (Nobel Prize, 1973) predicted a tunnelling effect for a system of two superconductors separated by a narrow dielectric (such a system is called Josephson junction): existence of a supercurrent through it and equations governing it. The overdamped Josephson junction is modeled by the family of differential equations on the 2-torus, dθdτ=1ω(cosθ+B+Acosτ), which is known as ...
Added: September 8, 2026
Pochinka O., Shmukler V., / Series math.RT "arXiv:1808.06395 [math.RT]". 2026.
Anosov flows have a long and rich history, firstly motivated by the
study of geodesic flows in negative curvature surface by Anosov and Sinai.
Not every closed manifold admits an Anosov flow for well-known reasons:
the fundamental group of a 3-manifold M admitting an Anosov flow must
have exponential growth, and M must be universally covered by R3. Nevertheless,
there ...
Added: August 31, 2026
Loubenets E. R., / Series arxiv.org "quant-ph". 2026. No. 2607.18050.
In many quantum applications it is important to know whether or not a Bell nonlocal two-qudit state exhibits its nonlocality under correlation scenarios with some given numbers S1,S2≥1 of generalized quantum measurements at two sites. In the present article, we find analytically a new general locality condition sufficient for a nonseparable Werner state with a ...
Added: July 21, 2026
Bolbachan V., / Series math "arxiv.org". 2024.
Chow polylogarithms are some special functions arising in explicit description of the Beilinson regulator map. The most interesting functional equation for this function reflects its vanishing on the boundary in the Bloch's cycle complex. We show that this functional equation formally follows from more simple ones, namely skew-symmetry, functoriality and multiplicativity.
To prove this, we study ...
Added: July 16, 2026
Bolbachan V., / Series math "arxiv.org". 2024.
Let K be a field of characteristic zero. We prove that its motivic cohomology in degree m−1 and weight m is rationally isomorphic to the cohomology of the polylogarithmic complex. This gives a partial extension of A. Suslin theorem describing the indecomposable K3 of a field. ...
Added: July 16, 2026
Panov V., Ryabchenko A., / Series arXiv "stat.ME". 2026. No. 2607.05048.
This paper investigates the problem of statistical inference for a mixture distribution consisting of a discrete and a continuous component, with a particular focus on the class of rational-infinitely divisible distributions. We consider non-parametric estimation of both components of the mixture as well as the quasi-L{é}vy measure, assuming that the mixture belongs to the class ...
Added: July 9, 2026
Konakov V., Kucher D., Mammen E., / Series arXiv "math". 2026. No. 2606.11142v1.
In this paper, we construct strong approximations for discrete-time Markov chains weakly converging to continuous diffusion processes, as well as for their perturbed counterparts. Under the assumption of bounded coefficients, we construct closely coupled versions of these processes on a shared probability space. In particular, for both non-degenerate and degenerate cases, we maximize the probability ...
Added: June 11, 2026
Dorovskiy A., / Series arXiv "math". 2026.
In this paper the structural stability of generic families of vector fields of the PC-HC class on the two-dimensional sphere is proved. A classification of these families up to moderate equivalence in neighborhoods of their large bifurcation supports is presented, based on such invariants as the configuration and the characteristic set. The realization lemma is proved. ...
Added: May 14, 2026
Taletskii D., / Series arXiv "math". 2026.
A vertex subset of a graph is called a \textit{distance-$k$ independent set} if the distance between any two of its distinct vertices is at least $k + 1$. For all $n,k \geq 1$, we determine the minimum possible number of inclusion-wise maximal distance-$k$ independent sets among all $n$-vertex trees. It equals~$n$ if $n \leq k ...
Added: May 1, 2026
Ovcharenko M., / Series arXiv "math". 2026.
We introduce an explicit class of tempered Laurent polynomials in the sense of Villegas and Doran--Kerr in n⩽4 variables including all Landau--Ginzburg models for smooth Fano threefolds with very ample anticanonical class. We check that it contains Landau--Ginzburg models for various Fano fourfolds which are complete intersections in smooth toric varieties and Grassmannians of planes, ...
Added: April 30, 2026
Zlotnik Alexander, / Series arXiv "math". 2026. No. 2602.03481v1.
We deal with the global in time weak solutions to the 1D compressible Navier-Stokes system of equations for large discontinuous initial data and nonhomogeneous boundary conditions of three standard types. We prove the Lipschitz-type continuous dependence of the solution $(\eta,u,\theta)$, in a norm slightly stronger than $L^{2,\infty}(Q)\times L^2(Q)\times L^2(Q)$, on the initial data $(\eta^0,u^0,e^0)$ in a ...
Added: April 18, 2026
A. S. Baybar, M. Yu. Puzachenko, R. B. Sandlersky, Geography and Natural Resources 2025 Vol. 46 No. S1 P. S15–S22
This article presents a methodology for landscape mapping based on the integration of long-term series of multispectral data and morphometric characteristics of the relief for various hierarchical levels. Using the example of the Central Forest Reserve and its adjacent territory, where both indigenous and anthropogenically modified geosystems are combined, it is shown that the identification ...
Added: January 14, 2026
Alexeevskaya E., Вестник арбитражной практики 2018 № 4 С. 3–5
The lack of a uniform understanding of the "judicial system" definition in Russia in the legal literature leads to a budgetary resource dispersion, which, ultimately, negatively affects the quality of justice and, as a result, destabilize the judicial system. Besides, the legal science lacks true comprehension of the Russian judicial system phenomenon, which prevents the ...
Added: August 20, 2024
Blank M., Nonlinearity 2024 Vol. 37 No. 6 Article 065006
We propose a novel unifying approach to study the shadowing property
for a broad class of dynamical systems (in particular, discontinuous and non-invertible)
under a variety of perturbations. In distinction to known constructions, our approach is local:
it is based on the gluing property which takes into account the shadowing under a single
(not necessarily small) perturbation. ...
Added: April 17, 2024
Blank M., Современная математика. Фундаментальные направления 2023 Т. 69 № 1 С. 50–61
A new approach based on the analysis of the influence of a single perturbation is proposed as a test for the shadowing property for a broad class of dynamical systems (in particular, non-autonomous) under a variety of perturbations. Applications for several interesting cases are considered in detail. ...
Added: March 23, 2024
Michael Blank, Mathematika 2023 Vol. 69 No. 2 P. 349–365
The purpose of this work is threefold:
(i) extend shadowing theory for discontinuous and non-invertible systems,
(ii) consider more general classes of perturbations (for example, small only on average),
(iii) establish a general theory based on the property that the shadowing holds
for the case of a single perturbation. The ``gluing'' construction used in the analysis
of the last property ...
Added: March 21, 2023
Bibilo Y., Glutsyuk A., Nonlinearity 2022 Vol. 35 No. 10 P. 5427–5480
The tunnelling effect predicted by Josephson (Nobel Prize, 1973) concerns the Josephson junction: two superconductors separated by a narrow dielectric. It states existence of a supercurrent through it and equations governing it. The overdamped Josephson junction is modelled by a family of differential equations on two-torus depending on three parameters: B (abscissa), A (ordinate), ω ...
Added: December 20, 2022
D. V. Pyat’ko, V. L. Chernyshev, Mathematical notes 2023 Vol. 113 No. 3 P. 538–551
The asymptotics of the number of end positions of a random walk on an oriented Hamiltonian metric graph is obtained. ...
Added: October 30, 2022
Blank M., Problems of Information Transmission 2022 Vol. 58 No. 3 P. 279–283
We study the problem of recovering distorted arbitrarily long messages written in some dynamically specified formal language. We obtain necessary and sufficient conditions on the language definition for an admissible message to exist in a neighborhood of a distorted message provided that local perturbations occur rarely. © 2022, Pleiades Publishing, Inc. ...
Added: October 25, 2022