Zobrazeno 1 - 10
of 92
pro vyhledávání: '"Orevkov, S. Yu."'
Autor:
Orevkov, S. Yu.
A rational function on a real algebraic curve $C$ is called separating if it takes real values only at real points. Such a function defines a covering $\mathbb R C\to\mathbb{RP}^1$. Let $c_1,\dots,c_r$ be connected components of $\mathbb R C$. M. Kum
Externí odkaz:
http://arxiv.org/abs/2412.02460
Autor:
Orevkov, S. Yu., Florens, V.
We define the Witt coindex of a link with non-trivial Alexander polynomial, as a concordance invariant from the Seifert form. We show that it provides an upper bound for the (locally flat) slice Euler characteristic of the link, extending the work of
Externí odkaz:
http://arxiv.org/abs/2405.14076
Autor:
Orevkov, S. Yu.
Publikováno v:
Mosc. Math. J., 24:3 (2024), 427-440
An oriented link is called $\mathbb C$-boundary if it is realizable as $(\partial B,A\cap\partial B)$ where $A$ is an algebraic curve in $\mathbb C^2$ and $B$ is an embedded $4$-ball. This notion was introduced by Michel Boileau and Lee Rudolph in 19
Externí odkaz:
http://arxiv.org/abs/2306.07438
Autor:
Kovalev, M. D., Orevkov, S. Yu.
Publikováno v:
Sbornik: Mathematics, 214 (2023), 1390-1414
A complete bipartite graph $K_{3,3}$, considered as a planar linkage with joints at the vertices and with rods as edges, in general admits only motions as a whole, i.e., is inflexible. Two types of its paradoxical mobility were found by Dixon in 1899
Externí odkaz:
http://arxiv.org/abs/2212.11231
Autor:
Orevkov, S. Yu.
Publikováno v:
J. Geom. Phys., 191 (2023), 104882
The following problem is studied: describe the triplets $(\Omega,g,\mu)$, $\mu=\rho\,dx$, where $g= (g^{ij}(x))$ is the (co)metric associated with the symmetric second order differential operator $L(f) = \frac{1}{\rho}\sum_{ij} \partial_i (g^{ij} \rh
Externí odkaz:
http://arxiv.org/abs/2210.15100
Autor:
Orevkov, S. Yu.
Publikováno v:
Sbornik: Mathematics, 213 (2022), 1530-1558
Let $f(m,n)$ be the number of primitive lattice triangulations of $m\times n$ rectangle. We compute the limits $\lim_n f(m,n)^{1/n}$ for $m=2$ and $3$. For $m=2$ we obtain the exact value of the limit which is equal to $(611+\sqrt{73})/36$. For $m=3$
Externí odkaz:
http://arxiv.org/abs/2201.12827
Autor:
Zvonilov, V. I., Orevkov, S. Yu.
Publikováno v:
Proceedings of the Steklov Institute of Mathematics, 2017, 298, 118-128
For a closed oriented surface $ \Sigma $ we define its degenerations into singular surfaces that are locally homeomorphic to wedges of disks. Let $X_{\Sigma,n}$ be the set of isomorphism classes of orientation preserving $n$-fold branched coverings $
Externí odkaz:
http://arxiv.org/abs/2201.03084
Autor:
Orevkov, S. Yu.
Publikováno v:
Geom. Funct. Anal. 31, 930-947 (2021)
We prove two inequalities for the complex orientations of a separating (Type I) non-singular real algebraic curve in $RP^2$ of any odd degree. We also construct a separating non-singular pseudoholomorphic curve in $RP^2$ of any degree congruent to 9
Externí odkaz:
http://arxiv.org/abs/2010.09130
Autor:
Orevkov, S. Yu.
Publikováno v:
Annales de la Facult\'e des sciences de Toulouse : Math\'ematiques (6), 33 (2024), 105-121
For any $n$, we describe all endomorphisms of the braid group $B_n$ and of its commutator subgroup $B'_n$, as well as all homomorphisms $B'_n\to B_n$. These results are new only for small $n$ because endomorphisms of $B_n$ are already described by Ca
Externí odkaz:
http://arxiv.org/abs/2010.02446
Autor:
Orevkov, S. Yu.
Publikováno v:
Funct Anal Its Appl 55, 59-74 (2021)
We compute the multivariate signatures of any Seifert link (that is a union of some fibers in a Seifert homology sphere), in particular, of the union of a torus link with one or both of its cores (cored torus link). The signatures of cored torus link
Externí odkaz:
http://arxiv.org/abs/2007.13468