?
Stable isotopy connectivity of gradient-like diffeomorphisms of 2-torus
Journal of Geometry and Physics. 2025. Vol. 207. Article 105352.
One of the most important problems in the theory of dynamical systems (mentioned in the Palis-Pugh list) is the construction of a stable arc between structural stable diffeomorphisms in the space of diffeomorphisms. The paper considers the gradient-like diffeomorphisms of 2-torus that induce an isomorphism of fundamental groups determined by a matrix (−1 0/ 0 −1). We prove that all such diffeomorphisms are stable isotopy connected.
Publication based on the results of:
Kupavskii A., Noskov F., Forum of Mathematics, Sigma 2026 Vol. 14 Article 124
We call a family of $s$ sets $\{F_1, \ldots, F_s\}$ a sunflower with $s$ petals if, for any distinct $i, j \in [s]$, one has $F_i \cap F_j = \cap_{u = 1}^s F_u$. The set $C = \cap_{u = 1}^s F_u$ is called the {\it core} of the sunflower. It is a classical result of ...
Added: October 8, 2026
Flamarion M. V., Pelinovsky E., Chaos, Solitons and Fractals 2026 Vol. 213 No. 2 Article 119245
This article concerns the study of modulational instability in the rotated-modified Gardner–Whitham (rmGW) equation. This model incorporates both quadratic and cubic nonlinearities, similarly to the Gardner equation, while also retaining the fully dispersive character of the Whitham equation together with a large-scale dispersive term analogous to that in the Ostrovsky equation. Using a classical multiple-scale asymptotic expansion, we ...
Added: October 8, 2026
Люксембург А. А., УРСС, 2005.
Изучается возможность автоматизированного построения математических теорий. Рассматривается дедуктивная система, основанная на языке логики предикатов первого порядка, объектами системы являются математические выражения или формулы, которые описывают математические объекты или их свойства. В дедуктивной системе выводятся математические определения и теоремы. Для доказательства теорем используются методы автоматического доказательства. Разработан алгоритм, выводящий часть формул системы. Для решения задачи используется аппарат математической ...
Added: October 7, 2026
Bernardin C., Gonçalves P., Olla S., Mathematical Physics Analysis and Geometry 2024 Vol. 27 No. 7
We consider the macroscopic limit for the space-time density fluctuations in the open symmetric simple exclusion in the quasi-static scaling limit. We prove that the distribution of these fluctuations converge to a gaussian space-time field that is delta correlated in time but with long-range correlations in space. ...
Added: October 6, 2026
Bernardin C., Chhaibi R., Najnudel J. et al., Probability Theory and Related Fields 2026 Vol. 195 P. 1823–1875
We study the celebrated Shiryaev-Wonham filter (Wonham, W.M., in J. Soc. Ind. Appl. Math. 347–369, 1964) in its historical setup, where the hidden Markov jump process has two states. We are interested in the weak noise regime for the observation equation. Interestingly, this becomes a strong noise regime for the filtering equations. Earlier results of ...
Added: October 5, 2026
Ismailov A., Spiridonov V., Успехи математических наук 2026 Т. 81 № 5 С. 183–184
Получена новая формула для цепной дроби Аски–Вильсона в форме отношения двух q-гипер-геометрических рядов. ...
Added: October 5, 2026
Abdulkhaev K., Shirokov D., Advances in Applied Clifford Algebras 2026 Vol. 36 P. 1–21
In this paper, we present explicit formulas for the inverse and determinant in geometric (Clifford) algebras over vector spaces of dimension n = 7. The derivation of these formulas is made possible by generalizing the concept of conjugation to basis conjugation operations. We further develop a general method for constructing such formulas over odd-dimensional spaces ...
Added: October 4, 2026
Kuninets A., IEEE Transactions on Information Theory 2026 P. 1–1
In this work we study the applicability of Quasi-Cyclic Subfield Subcodes of Dual Elliptic (QC-SSDE) codes for integration into code-based cryptographic schemes. Detailed algorithms are provided for constructing parity-check matrices as well as block-circulant parity-check matrices for this family of codes, accompanied by empirical results that enable the construction of QC-SSDE codes with predetermined dimensions. ...
Added: October 3, 2026
Medvedev G., Alexandrov Artem, Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2026 Vol. 114 Article 044102
Graphons are measurable functions used to describe the asymptotic behavior of convergent graph families. Originally motivated by problems in combinatorics and graph theory, graphons have found numerous applications in the modeling and analysis of dynamical processes on networks. In this work, we use graphons to formulate the Ising model on convergent graph sequences, which include ...
Added: October 2, 2026
Pochinka O., Baranov D., Nozdrinova E., Теоретическая и математическая физика 2026 Т. 229 № 1 С. 3–14
The Birman–Williams problem on describing the planetary link of a fibered knot K in S^3 has been partially solved. Using Nielsen's theory for the classification of periodic surface homeomorphisms and its close relationship with the theory of gradient-like diffeomorphisms, it is proved that the planetary link of the trefoil (the unique periodic fibered knot of genus ...
Added: October 2, 2026
Lubashevsky I., Lubashevskiy V., Physica D: Nonlinear Phenomena 2026 Vol. 498 Article 135441
We develop a novel cloud-function formalism describing the dynamical relationship between sensory-information processing in large-scale brain networks (supraliminal processing) and the content of the mental representation of an observed object. The formalism combines elements of neural field theory for large-scale neural activity with the spatial characteristics of perceived objects and their embedding in the environment ...
Added: October 2, 2026
Zlotnik A., Математические заметки 2026 Т. 120 № 6 С. 1005–1009
Численным методам решения систем газодинамических уравнений посвящена обширная литература. Ранее было разработано и успешно апробировано специальное семейство симметричных по пространству консервативных разностных методов, основанных на предварительной кинетической, точнее, квазигазодинамической (КГД), регуляризации этих уравнений. Актуальной задачей является построение численных методов, которые обладают не только свойством консервативности по массе, импульсу и полной энергии, но и удовлетворяют условиям энтропийной ...
Added: October 1, 2026
Vyugin I. V., Sashadhar D., Algebra and Number Theory 2026 P. 1–10
We study the K-Fibonacci sequence Fp modulo prime p. Cardinalities of sets |Fp+Fp| and |Fp⋅Fp| are estimated. We present the method of estimating doubling constant of some m-dimensional recurrent sets in Fp. ...
Added: October 1, 2026
Kuksin S., Dynamical Systems 2026
We study the mixing properties of discrete-time and continuous-time dissipative dynamical systems driven by bounded mixing random forces. The continuous-time systems are
reduced to discrete-time random dynamical systems generated by time-one maps, so that
the main analysis is carried out in the discrete setting. We introduce a class of mixing random forcings whose regular conditional distributions with ...
Added: October 1, 2026
Kuksin S., Shirikyan A., Journal of Dynamics and Differential Equations 2026 P. 1098–1100
The paper deals with the problem of large-time behaviour of trajectories for discrete-time dynamical systems driven by a random noise. Assuming that the phase space is finite-dimensional and compact, and the noise is a Markov process with a transition probability satisfying some regularity hypotheses, we prove that all the trajectories converge to a unique measure ...
Added: October 1, 2026
Potanin B., Dolgikh S., Statistics and Probability Letters 2027 Article 110984
We derive bounds on the gradient and Hessian of the log-CDF, ln F(x), of the multivariate normal distribution. These bounds scale linearly and quadratically in ‖x‖ , respectively, with constants depending only on the covariance matrix. We demonstrate the usefulness of these bounds by proving asymptotic normality of the maximum-likelihood estimator of the multivariate probit ...
Added: October 1, 2026
A. V. Pereskokov, Journal of Mathematical Sciences 2026 Vol. 302 No. 4 P. 531–545
We consider the Zeeman effect problem for the hydrogen atom in a magnetic field using
irreducible representations of the Karasev–Novikova algebra with quadratic commutation
relations. We find the asymptotics of a series of eigenvalues and the corresponding
asymptotic eigenfunctions near the upper boundaries of spectral clusters. ...
Added: October 1, 2026
Nozdrinova E., Pochinka O., Математические заметки 2025 Т. 118 № 6 С. 895–899
В настоящей работе рассматривается класс градиентно-подобных диффеоморфизмов замкнутых поверхностей с отрицательной эйлеровой характеристикой. Устанавливается, что любые такие изотопные тождественному диффеоморфизмы соединяются устойчивой дугой (содержащей конечное число седло-узловых бифуркаций). Полученный результат контрастирует с устойчивой классификацией градиентно-подобных диффеоморфизмов 2-сферы или 2-тора, согласно которой множество изотопных тождественному диффеоморфизмов на таких поверхностях разбиваются на счетное число классов устойчивой связности. ...
Added: December 1, 2025
Pochinka O., Baranov D., Working papers by Cornell University. Series math "arxiv.org" 2025 P. 1–22
An isotopy between two diffeomorphisms f0, f1 : M → M means the existence of an arc {ft : M → M, t ∈ [0, 1]} connecting them in the space of diffeomorphisms. Among such arcs there are so-called stable arcs, which do not qualitatively change under small perturbations. In the present paper we consider a set of gradient-like diffeomorphisms ...
Added: November 26, 2025
E. V. Nozdrinova, O. V. Pochinka, E. V. Tsaplina, Doklady Mathematics 2024 Vol. 110 No. 2 P. 379–385
It is well known that the mapping class group of the two-dimensional sphere is isomorphic to the group {-1,+1}. At the same time, the class +1(-1) contains all orientation-preserving (orientation-reversing) diffeomorphisms and any two diffeomorphisms of the same class are diffeotopic, that is, they are connected by a smooth arc of diffeomorphisms. On the other hand, ...
Added: October 23, 2024
Nozdrinova E., Pochinka O., Tsaplina E., Известия РАН. Серия математическая 2024 Т. 88 № 3 С. 111–138
Классический подход к изучению динамических систем состоит в представлении динамики системы в виде “источник–сток”, т. е. в выделении дуальной пары аттрактор–репеллер, которые являются притягивающими и отталкивающими множествами для всех остальных траекторий системы. Если удается выбрать дуальную пару аттрактор–репеллер так, что пространство орбит в их дополнении (характеристическое пространство орбит) является связным, то это создает предпосылки для нахождения полных топологических инвариантов динамической системы. ...
Added: June 1, 2024
Baranov D., Nozdrinova E., Pochinka O., Уфимский математический журнал 2024 Т. 16 № 1 С. 11–23
В настоящей работе рассматриваются изотопные тождественному градиентно-подобные диффеоморфизмы двумерного тора. Изотопность диффеоморфизмов, заданных на 𝑛-многообразии означает существование некоторой дуги, соединяющей их в пространстве диффеоморфизмов. Если изотопные диффеоморфизмы являются структурно устойчивыми (качественно не меняющими своих свойств при малых шевелениях), то естественно ожидать существования устойчивой дуги (качественно не меняющей своих свойств при малых шевелениях) их соединяющей. В этом ...
Added: March 12, 2024
О. В. Починка, Е. А. Таланова, Д. Д. Шубин, Математический сборник 2023 Т. 214 № 8 С. 94–107
It is known that the topological conjugacy of gradient-like 3-difepheromorphisms with a single saddle point is completely determined by the equivalence of Hopf knots on the manifold of S^2 × S^1, which are the projections of a one-dimensional saddle separatics in the basin of node point, and the ambient manifold for all such diffeomorphisms is ...
Added: July 27, 2023
Vyacheslav Z. Grines, Vladislav S. Medvedev, Evgeny V. Zhuzhoma, Regular and Chaotic Dynamics 2022 Vol. 27 No. 6 P. 613–628
Let M^n, , n⩾3, be a closed orientable n-manifold and G(M^n) be the set of A-diffeomorphisms f:M^n→M^n whose nonwandering set satisfies the following conditions: (1) each nontrivial basic set of the nonwandering set is either an orientable codimension one expanding attractor or an orientable codimension one contracting repeller; (2) the invariant manifolds of isolated saddle periodic points intersect transversally and codimension one separatrices of such ...
Added: January 31, 2023