On sums and products in a field
Czechoslovak Mathematical Journal, Tome 72 (2022) no. 3, pp. 817-823
We study sums and products in a field. Let $F$ be a field with ${\rm ch}(F)\not =2$, where ${\rm {\rm ch} } (F)$ is the characteristic of $F$. For any integer $k\geq 4$, we show that any $x\in F$ can be written as $a_1+\dots +a_k$ with $a_1,\dots ,a_k\in F$ and $a_1\dots a_k=1$, and that for any $\alpha \in F \setminus \{0\}$ we can write every $x\in F$ as $a_1\dots a_k$ with $a_1,\dots ,a_k\in F$ and $a_1+\dots +a_k=\alpha $. We also prove that for any $x\in F$ and $k\in \{2,3,\dots \}$ there are $a_1,\dots ,a_{2k}\in F$ such that $a_1+\dots +a_{2k}=x=a_1\dots a_{2k}$.
We study sums and products in a field. Let $F$ be a field with ${\rm ch}(F)\not =2$, where ${\rm {\rm ch} } (F)$ is the characteristic of $F$. For any integer $k\geq 4$, we show that any $x\in F$ can be written as $a_1+\dots +a_k$ with $a_1,\dots ,a_k\in F$ and $a_1\dots a_k=1$, and that for any $\alpha \in F \setminus \{0\}$ we can write every $x\in F$ as $a_1\dots a_k$ with $a_1,\dots ,a_k\in F$ and $a_1+\dots +a_k=\alpha $. We also prove that for any $x\in F$ and $k\in \{2,3,\dots \}$ there are $a_1,\dots ,a_{2k}\in F$ such that $a_1+\dots +a_{2k}=x=a_1\dots a_{2k}$.
DOI :
10.21136/CMJ.2021.0184-21
Classification :
11D85, 11P99, 11T99
Keywords: field; rational function; restricted sum; restricted product
Keywords: field; rational function; restricted sum; restricted product
@article{10_21136_CMJ_2021_0184_21,
author = {Zhou, Guang-Liang and Sun, Zhi-Wei},
title = {On sums and products in a field},
journal = {Czechoslovak Mathematical Journal},
pages = {817--823},
year = {2022},
volume = {72},
number = {3},
doi = {10.21136/CMJ.2021.0184-21},
mrnumber = {4467944},
zbl = {07584104},
language = {en},
url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.2021.0184-21/}
}
TY - JOUR AU - Zhou, Guang-Liang AU - Sun, Zhi-Wei TI - On sums and products in a field JO - Czechoslovak Mathematical Journal PY - 2022 SP - 817 EP - 823 VL - 72 IS - 3 UR - http://geodesic.mathdoc.fr/articles/10.21136/CMJ.2021.0184-21/ DO - 10.21136/CMJ.2021.0184-21 LA - en ID - 10_21136_CMJ_2021_0184_21 ER -
Zhou, Guang-Liang; Sun, Zhi-Wei. On sums and products in a field. Czechoslovak Mathematical Journal, Tome 72 (2022) no. 3, pp. 817-823. doi: 10.21136/CMJ.2021.0184-21
[1] Elkies, N. D.: On the areas of rational triangles or how did Euler (and how can we) solve $xyz(x+y+z)=a$?. Available at \let \relax\brokenlink{ http://www.math.harvard.edu/ elkies/{euler_14t.pdf}} (2014), 50 pages.
[2] Klyachko, A. A., Mazhuga, A. M., Ponfilenko, A. N.: Balanced factorisations in some algebras. Available at , 4 pages. | arXiv
[3] Klyachko, A. A., Vassilyev, A. N.: Balanced factorisations. Available at , 8 pages. | arXiv | MR
[4] Zypen, D. van der: Question on a generalisation of a theorem by Euler. Question 302933 at MathOverflow, June 16, 2018. Available at http://mathoverflow.net/questions/302933
Cité par Sources :