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Algebra and model theory 2025. Volume 16
Издательство НГТУ, 2025.
Under the general editorship: M. Shahryari, S. V. Sudoplatov
The 17th International Summer School-Conference “Problems Allied to Model Theory and Universal Algebra” was held on 19–26 of June 2025 at Sobolev Institute of Mathematics, Novosibirsk State Technical University NETI and at the Camping Center “Erlagol” in Altai mauntains. The School was organized by Algebra and Mathematical Logic Department of Novosibirsk State Technical University (NSTU NETI) and Sobolev Institute of Mathematics of Siberian Branch of Russian Academy of Sciences (IM SB RAS). The School was supported by Grant of International Mathematical Center in Akademgorodok and by Faculty of Applied Mathematics and Computer Science of NSTU NETI. The school-conference included both online and in-person talks. At the school-conference, there were participants from Russia, Kazakhstan, Uzbekistan, China, Iran, Oman, France, Greece, Hungary, Poland. They made 50 talks. Within the school-conference, the discussions on actual problems on Model Theory, Algebra and related subjects were held. Information about the conference is posted on the conference website https://erlagol.ru.
Chapters
Polyakov N. L., В кн.: Algebra and model theory 2025. Volume 16.: ., 2025. С. 134–139.
In [1], the concept of a skew limit ultrapower of ordinal rank of an arbitrary model $\mathfrak M$ with respect to an ultrafilter $\mathfrak u$ was introduced for a model-theoretic characterization of some natural preorders on the set of ultrafilters on the set $\beta\omega$. We will show that this concept admits broad generalizations that can ...
Added: November 24, 2025
Podinovskiy V. V., Нелюбин А. П., Автоматика и телемеханика 2026 № 8 С. 110–123
Для многокритериальных задач принятия решений по аналогии с качественной вероятностью введены понятия полной и частичной качественной важности как бинарных отношений, обладающих постулируемыми
свойствами. Предложено новое определение отношения нестрогого предпочтения на множестве вариантов решений, порождаемое качественной
важностью. Исследованы его свойства. Указаны аналитические правила,
позволяющие попарно сравнивать варианты по предпочтительности. Проведено сравнение новых отношений предпочтения с разработанными ранее для задач, ...
Added: September 9, 2026
Podinovskiy V. V., Нелюбин А. П., Автоматика и телемеханика 2026 № 7 С. 113–126
Рассматриваются задачи принятия решений, когда предпочтения оцениваются в порядковой шкале, а возможности реализации значений
неопределенного фактора описываются качественной вероятностью (полной или только частичной). Вводятся определения отношений предпочтения и безразличий на множестве стратегий. Предлагаются простые
решающие правила, позволяющие сравнивать стратегии по предпочтительности, и приводятся иллюстративные примеры. ...
Added: September 9, 2026
Chemical Papers 2026
Benzenoid hydrocarbons are structurally regular aromatic compounds, which makes them well suited for quantitative structure–property relationship (QSPR) studies. This study presents a QSPR analysis of nineteen benzenoid hydrocarbon species using degree-based topological co-indices. We developed a Python program to compute eleven degree-based topological co-indices from molecular graphs and evaluated their ability to explain variations in ...
Added: September 8, 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
Glutsyuk A., / Series arXiv "math". 2026.
A planar dual billiard is a planar curve γ equipped with a family (σP)|P∈γ of projective involutions of the projective lines LP tangent to γ at P that fix P. A dual billiard is called rationally integrable, if there exists a rational function R(x,y) of two variables (called first integral) whose restriction to each tangent ...
Added: September 8, 2026
Alexandrov A., Glutsyuk A., Journal of Differential Equations 2026 Vol. 465 Article 114178
The overdamped Josephson junction in superconductivity theory can be modeled by the family of dynamical systems on the torus, which is known as the RSJ model. This family admits an equivalent description by a family of second-order differential equations: special double confluent Heun equations. In the present paper, we construct two new families of dynamical systems on ...
Added: September 8, 2026
Glutsyuk A., Inventiones Mathematicae 2026 Vol. 245 P. 977–1058
A caustic of a strictly convex planar bounded billiard is a smooth curve whose tangent lines are reflected from the billiard boundary to its tangent lines. The famous Birkhoff Conjecture, studied by many mathematicians, states that if the billiard boundary has an inner neighborhood foliated by closed caustics, then it is an ellipse. In the paper we study ...
Added: September 8, 2026
Prikhodko Artem, Kubrak D., Compositio Mathematica 2026 Vol. 162 No. 6 P. 1377–1438
In this follow-up paper we show that smooth Hodge-proper stacks over O𝐾 are ℚ𝑝-locally acyclic: namely the natural map between étale ℚ𝑝-cohomology of the algebraic and Raynaud generic fibers is an equivalence. This establishes the ℚ𝑝-case of general conjectures made in D. Kubrak and A. Prikhodko [p-adic Hodge theory for Artin stacks, Mem. Amer. Math. ...
Added: September 7, 2026
Ismailov A., Constructive Approximation 2026
The measure of the positivity set {x ∈ [0; 2π] | f (x) > 0} of a trigonometric polynomial f is bounded from below by the Motzkin density.
We generalize the bound to polynomials in several variables and almost periodic functions.
We then use these generalizations to extend known results on Taikov’s problem. ...
Added: September 7, 2026
Kelbert M., Statistics 2026 Vol. 60
We present variational representations for the weighted divergencies
and exponential error function, and discuss implications for the
statistical inference and entropic optimal transport. ...
Added: September 7, 2026
Kucheryavyy P., Математические заметки 2026 Т. 2026 № 120 С. 380–401
В работе изучаются перестановки, возникающие при упорядочивании по возрастанию дробных долей произведений элементов фиксированной целочисленной последовательности на вещественный параметр. Исследуется количество различных перестановок, которые можно получить таким образом при изменении этого параметра от нуля до единицы. ...
Added: September 7, 2026
Осипов Д.В., Математический сборник 2026 Т. 217 № 9 С. 130–146
Изучаются законы взаимности, связанные с комплексными линейными расслоениями на расслоениях на ориентируемые окружности. В частности, доказывается следующий закон взаимности. Пусть B – комплексное многообразие и πi:Mi→B – расслоение на ориентируемые окружности, где индекс i пробегает конечное множество. Пусть Li и Ni – комплексные линейные расслоения на каждом многообразии Mi. Закон взаимности утверждает, что сумма всех элементов (πi)∗(c1(Li)∪c1(Ni)), где (πi)∗ – ...
Added: September 3, 2026
Basalaev A., Rarovskii A., Journal of Singularities 2026 Vol. 30 P. 61–80
Saito theory associates to an isolated singularity rich structure that plays an important role in mirror symmetry. In this note we construct Saito theory for A and D type Landau-Ginzburg orbifolds. Namely, for the pairs (f,G), where f defines an isolated singularity of A and D type and G is a group of symmetries of ...
Added: September 1, 2026
Rybakov M., Shkatov D., Journal of Logic and Computation 2026 Vol. 36 No. 6 Article exag026
We prove Pi-1-1-hardness, and thus lack of recursive axiomatizability, of constant-domain modal predicate logics defined by a class of Dedekind complete linear Kripke frames containing a frame with an infinitely increasing chain of worlds. The result holds even for the language with one unary predicate letter, one propositional letter, and two individual variables. ...
Added: September 1, 2026
Селянин Ф. И., Moscow Mathematical Journal 2026 Vol. 26 No. 2 P. 167–187
Minkowski mixed volume of n subpolytopes D1,…,Dn of a polytope P⊂Rn clearly does not exceed the normalized volume n!Vol(P). Equality holds if and only if the subpolytopes are interlaced, i.e., each proper face F⊊P intersects at least dim(F)+1 of the polytopes Di. Efficiently computing mixed volumes for more general collections of subpolytopes is crucial for estimating the complexity of numerically solving polynomial systems.
Motivated by relaxing the bound dim(F)+1 to dim(F), we ...
Added: August 31, 2026
Kazaryan M., Dunin-Barkowski P., Bychkov B. et al., International Mathematics Research Notices 2026 Vol. 14 Article rnag146
We prove a recent conjecture of the fourth named author with P. Norbury that states a system of universal polynomial relations among the kappa classes on the moduli spaces of algebraic curves. The proof involves localization and materialization analysis of the spin Gromov–Witten theory of the projective line and is dictated by Z 2 -equivariant ...
Added: August 31, 2026
Тула: Тульский государственный педагогический университет им. Л.Н. Толстого, 2025.
Сборник содержит материалы, представленные на XXIV Международной конференции «Алгебра, теория чисел, дискретная геометрия и многомасштабное моделирование: современные проблемы, приложения и проблемы истории», посвящённой 110-летию со дня рождения академика Юрия Владимировича Линника и 110-летию со дня рождения профессора Андрея Борисовича Шидловского и 80-летию со дня рождения профессора Геннадия Ивановича Архипова. Материалы конференции будут полезны научным работникам, ...
Added: August 27, 2026
Ustinov A., Алфутова Н. Б., МЦНМО, 2022.
The book is a collection of problems in mathematics, designed primarily for high school students with advanced study of mathematics, interested in exact sciences. It will also be useful for mathematics teachers and students studying mathematics in higher educational institutions. A significant part of the material can be used to prepare for written and oral ...
Added: January 21, 2025
[б.и.], 2023.
Proceedings of the international conference "Mal'tsev Meeting 2023" ...
Added: November 30, 2024
Novosibirsk: ., 2023.
The 15th International Summer School-Conference “Problems Allied to
Model Theory and Universal Algebra” was held on 21–29 of June 2023 at
Novosibirsk State Technical University NETI and at the camping center
“Erlagol” in Altai mountains. The School was organized by Algebra and
Mathematical Logic Department of Novosibirsk State Technical University
(NSTU NETI) and Sobolev Institute of Mathematics of Siberian Branch ...
Added: November 23, 2023
Veryovkin Y., Труды Математического института им. В.А. Стеклова РАН 2022 Т. 318 С. 31–42
The lower central series of a right-angled Coxeter group RCK and the corresponding graded Lie algebra L(RCK) associated with the lower central series of a right-angled Coxeter group are studied. Relations are obtained in the graded components of the Lie algebra L(RCK). A basis of the fourth graded component of L(RCK) for groups with at most four generators is described. ...
Added: November 23, 2023
Мордкович А. Г., Семенов П. В., Александрова Л. А. et al., М.: Просвещение, 2021.
The textbook is written in accordance with GEF LLC and is included in the a long line of textbooks for grades 7-9; supports time-new models of studying algebra: basic and advanced. Outline-theoretical material is accompanied by a detailed looking at a large number of examples, practical tasks presented at three levels of difficulty. At the ...
Added: January 30, 2023
Мордкович А. Г., Семенов П. В., Александрова Л. А. et al., М.: Просвещение, 2021.
The textbook is written in accordance with GEF LLC and is included in the a long line of textbooks for grades 7-9; supports time-new models of studying algebra: basic and advanced. Outline-theoretical material is accompanied by a detailed looking at a large number of examples, practical tasks presented at three levels of difficulty. At the ...
Added: January 30, 2023