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Ilya Gorshkov

Publications and source records attributed to Ilya Gorshkov.

25 records · Page 2Linked to original sources
arXiv2018

On Thompson's conjecture for finite simple groups

Let $G$ be a finite group, $N(G)$ be the set of conjugacy classes of the group $G$. In the present paper it is proved $G\simeq L$ if $N(G)=N(L)$, where $G$ is a finite group with trivial center and $L$ is a finite simple group.

math.GR↗
arXiv2018

On groups having the prime graph as alternating and symmetric groups

The {\it prime graph} $Γ(G)$ of a finite group $G$ is the graph whose vertex set is the set of prime divisors of $|G|$ and in which two distinct vertices $r$ and $s$ are adjacent if and only if there exists an element of $G$ of order $rs$. Let $A_n$ ($S_n$) denote the alternating (symmetric) group of degree $n$. We prove that if $G$ is a finite group with $Γ(G)=Γ(A_n)$ or $Γ(G)=Γ(S_n)$, where $n\geq19$, then there exists a normal subgroup $K$ of $G$ and an integer $t$ such that $A_t\leq G/K\leq S_t$ and $|K|$ is divisible by at most one prime greater than $n/2$.

math.GR↗
arXiv2016

Thompson's conjecture for alternating group

Let $G$ be a finite group, and let $N(G)$ be the set of sizes of its conjugacy classes. We show that if a finite group $G$ has trivial center and $N(G)$ equals to $N(Alt_n)$ or $N(Sym_n)$ for $n\geq 23$, then $G$ has a composition factor isomorphic to an alternating group $Alt_k$ such that $k\leq n$ and the half-interval $(k, n]$ contains no primes. As a corollary, we prove the Thompson's conjecture for simple alternating groups.

math.GR↗
arXiv2016

On Thompson's conjecture for alternating group of large degree

For a finite group $G$, let $N(G)$ denote the set of conjugacy class sizes of $G$. We show that if every finite group $G$ with trivial center such that $N(G)$ equals to $N(Alt_n)$, where $n>1361$ and at least one of numbers $n$ or $n-1$ are decomposed into a sum of two primes, then $G\simeq Alt_n$.

math.GR↗