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arXiv 2206.01554math.NTmath.GR
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关于与素数阶特殊线性群有关的线性化多项式的伽罗瓦群

On Galois groups of linearized polynomials related to the special linear group of prime degree

Rod Gow, Gary McGuire

摘要:

设$F$是素特征$p$的域,$q$是$p$的幂。我们假设$F$包含$q$阶的有限域。$F$上的$q$ -多项式$L$是多项式环$F[x]$的元素,具有以下性质:作为$L$中具有非零系数的项出现的$x$的那些幂的指数为$q$的幂。如果$L$的首项的指数是$q^n$,我们说$L$有$q$ -度$n$。我们假设$L$的$x$项的系数不为零。我们研究了在$F[x]$中$L(x)/x$不可约的条件下,$L$在$F$上的Galois群$G$.众所周知,如果$L$有$q$ -度$n$,则它的根是$q$阶域上的$n$ -维向量空间,并且$G$线性地作用在这个空间上。我们的主要定理如下。本文考虑一元$q$ -多项式$L$,其$q$ -次数为素数$r$,即$L(x)/x$在$F$上不可约.设$L$的$x$项的系数为$(-1)^r$,证明了当$q>2$时,$L$在$F$上的Galois群必为$q$阶域上的特殊线性群$SL(r,q)$.证明了射影特殊线性群$PSL(r,q)$的一个射影形式,并给出了当$q=2$ .

英文摘要:

Let $F$ be a field of prime characteristic $p$ and let $q$ be a power of $p$. We assume that $F$ contains the finite field of order $q$. A $q$-polynomial $L$ over $F$ is an element of the polynomial ring $F[x]$ with the property that those powers of $x$ that occur as terms of $L$ with nonzero coefficient have exponent a power of $q$. If the exponent of the leading term of $L$ is $q^n$, we say that $L$ has $q$-degree $n$. We assume that the coefficient of the $x$ term of $L$ is nonzero. We investigate the Galois group $G$, say, of $L$ over $F$, under the assumption that $L(x)/x$ is irreducible in $F[x]$. It is well known that if $L$ has $q$-degree $n$, its roots are an $n$-dimensional vector space over the field of order $q$ and $G$ acts linearly on this space. Our main theorem is the following. We consider a monic $q$-polynomial $L$ whose $q$-degree is a prime, $r$, say, with $L(x)/x$ irreducible over $F$. Assuming that the coefficient of the $x$ term of $L$ is $(-1)^r$, we show that the Galois group of $L$ over $F$ must be the special linear group $SL(r,q)$ of degree $r$ over the field of order $q$ when $q>2$. We also prove a projective version for the projective special linear group $PSL(r,q)$, and we present the analysis when $q=2$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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