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О деревьях заданного диаметра с экстремальным количеством k-дистанционных независимых множеств
Дискретный анализ и исследование операций. 2023. Т. 30. № 3. С. 111–131.
The set of vertices of a graph is called distance-k independent if the distance between any two of its vertices is greater than some integer k ⩾ 1. In this paper we describe n-vertex trees with a given diameter d which have maximum and minimum possible number of distance-k independent sets among all such trees. The maximum problem is solved for the case 1 < k < d ⩽ 5. The minimum problem is significantly more simple and is solved for all 1 < k < d < n.
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
Kazaryan M., Dunin-Barkowski P., Bychkov B. et al., Communications in Mathematical Physics 2026 Vol. 407 No. 69
We prove that for any initial data on a genus zero spectral curve the cor responding correlation differentials of topological recursion are KP integrable. As an application we prove KP integrability of partition functions associated via ELSV-type formulas to the r-th roots of the twisted powers of the log canonical bundles ...
Added: August 31, 2026
Gromov V., Переслегин С. Б., Переслегина Е. Б. et al., СПб.: Полакс, 2026.
Механизм происходящих в мире изменений носит эволюционный, а не экологический характер. Иначе говоря, Человечество столкнулось с кризисом развития, который имеет три независимые составляющие: кризис индустриального общества (фазовый кризис), кризис научного мышления (эпистемный кризис) и кризис формата существования разума (социосистемный кризис). Доклад посвящён аспектам этого триединого кризиса и возможным путям его преодоления, не сводящимся к первичному ...
Added: August 31, 2026
Devyatov R. A., Mathematical notes 2026 Vol. 119 No. 3 P. 782–786
Let G/B be a flag variety over ℂ, where G is a simple algebraic group with a simply laced Dynkin diagram, and B is a Borel subgroup. We say that the product of classes of Schubert divisors in the Chow ring is multiplicity free if it is possible to multiply it by a Schubert class ...
Added: August 30, 2026
Bayer A., Kuznetsov A., Macrì E., Journal fuer die reine und angewandte Mathematik 2026 Vol. 2026 No. 836 P. 111–162
We give a self-contained and simplified proof of Mukai’s classification of prime Fano threefolds of index 1 and genus g ≥ 6 with at most factorial terminal singularities, and of its extension to higher dimension. ...
Added: August 30, 2026
Bayer A., Kuznetsov A., Macrì E., Compositio Mathematica 2026 Vol. 162 No. 1 P. 59–99
We give a proof of Mukai’s theorem on the existence of certain exceptional vector bundles on prime Fano threefolds. To our knowledge this is the first complete proof in the literature. The result is essential for Mukai’s biregular classification of prime Fano threefolds, and for the existence of semiorthogonal decompositions in their derived categories. Our ...
Added: August 30, 2026
Guseva L., Novikov A., Advances in Mathematics 2026 Vol. 503 Article 111211
We prove that the Kuznetsov–Polishchuk exceptional collections on rational homogeneous spaces of the symplectic groups Sp(2n,C) are full and consist of vector bundles. To achieve this, we construct several classes of complexes, which we call generalized staircase complexes, symplectic staircase complexes and secondary staircase complexes — each of which may be of independent interest. ...
Added: August 30, 2026
Polishchuk A., Rains E., Journal of the Institute of Mathematics of Jussieu 2026 Vol. 25 No. 1 P. 339–373
We prove that for every relatively prime pair of integers (d,r) with r>0, there exists an exceptional pair (O,V) on any del Pezzo surface of degree 4, such that V is a bundle of rank r and degree d. As an application, we prove that every Feigin-Odesskii Poisson bracket on a projective space can be ...
Added: August 30, 2026
Kazhdan D., Polishchuk A., Pure and Applied Mathematics Quarterly 2026 Vol. 22 No. 3 P. 1115–1166
We continue the study of automorphic functions associated with a curve C over the ring k[ε]/(ε²), where k is a finite field, begun in arXiv:2303.16259. Namely, we study an example of theta-lifting in this framework and show that it can be understood in terms of the orbit decomposition of the space of automorphic functions S(SL₂(F)\SL₂(A_C)) ...
Added: August 30, 2026
Kuznetsov A. P., Sataev I. R., Stankevich N., Chaos 2026 Vol. 36 No. 8 Article 083131
A radio-physical system, namely, a two-mode van der Pol generator, is considered. It is shown that this system demonstrates two types of chaos: with one and two zero Lyapunov exponents. The regions of the second type of chaos are surrounded by bifurcation lines of invariant tori doubling. Quasi-periodic structures of various shapes are embedded within ...
Added: August 30, 2026
Shirokov N. A., Rozenblum G., Israel Journal of Mathematics 2026 P. 1–30
We establish that a generalized H\¨older continuous function on an (m−2)-Ahlfors regular compact set in Rm can be approximated by solutions of an elliptic equation, with the rate of approximation determined by the continuity modulus of the function ...
Added: August 29, 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
Gurvich V., Krnc M., Vyalyi M., Results in Mathematics 2025 Vol. 80 Article 117
An amoeba is a tree together with instructions how to iteratively grow trees by adding paths of a fixed length . This paper analyses such a growth process. An amoeba is mortal if all versions of the process are finite, and it is immortal if they are all infinite. We obtain some necessary and some ...
Added: August 24, 2025
Kuzmin N., Malyshev D., Математические заметки 2024 Т. 115 № 3 С. 371–384
Паросочетанием графа называется любое множество его ребер, попарно не имеющих общих вершин. Важным параметром графов, находящим свое применение в математической химии, является индекс Хосойи, определяемый как количество их паросочетаний. Ранее рассматривались и были полностью решены задачи максимизации этого индекса для 𝑛-вершинных деревьев c двумя, тремя, четырьмя листьями при любом достаточно большом 𝑛. В этой работе ...
Added: April 15, 2024
Taletskii D., Дискретный анализ и исследование операций 2024 Т. 31 № 1 С. 109–128
The set of graph vertices J_k is called k-dominating independent (k > 1) if its vertices are pairwise adjacent and every vertex not from J_k is adjacent to at least k vertices from J_k. In the presentb paper we obtain new upper bounds for the number of k-dominating independent sets for k > 2 in ...
Added: March 25, 2024
D. S. Taletskii, Sbornik Mathematics 2023 Vol. 214 No. 11 P. 1627–1650
The following conjecture is formulated: if the average vertex degree in a graph is not greater than a positive integer k⩾1, then the number of k-dominating sets in this graph does not exceed the number of its independent sets, and these numbers are equal to each other if and only if the graph is k-regular. This conjecture is proved for k∈{1,2}. ...
Added: March 25, 2024
Qian X., Guan X., Jia J. et al., Journal of Optimization Theory and Applications 2024 Vol. 200 P. 524–554
Given an undirected tree T = (V, E) and a value σ > 0, every edge e ∈ E has a lead time l(e) and a capacity c(e). Let Pst be the unique path connecting s and t. A transmission time of sending σ units data from s to t ∈ V is Q(s, t,σ) ...
Added: January 18, 2024
D. S. Taletskii, Journal of Applied and Industrial Mathematics (перевод журналов "Сибирский журнал индустриальной математики" и "Дискретный анализ и исследование операций") 2023 Vol. 17 No. 3 P. 664–677
The set of vertices of a graph is called distance-k independent if the distance between any two of its vertices is greater than some integer k ≥ 1. In this paper, we describe n-vertex trees with a given diameter d that have the maximum and minimum possible number of distance-k independent sets among all such ...
Added: November 8, 2023
Taletskii D., Математический сборник 2023 Т. 214 № 11 С. 133–156
Сформулирована следующая гипотеза: если средняя степень вершин графа не превосходит натурального числа k ⩾ 1, то количество его k-доминирующих множеств не превосходит количества его независимых множеств, при этом равенство возможно, если и только если граф является k-регулярным. Эта гипотеза доказана для случая k ∈ {1,2}. ...
Added: November 2, 2023
Zhang Q., Guan X., Jia J. et al., Journal of Global Optimization 2023 Vol. 86 P. 251–284
We consider the restricted inverse optimal value problem on shortest path under weighted l1 norm on trees (RIOVSPT1). It aims at adjusting some edge weights to minimize the total cost under weighted l1 norm on the premise that the length of the shortest root-leaf path of the tree is lower-bounded by a given value D, ...
Added: June 2, 2023