Is $e^p\in\mathbb{Q}_p$ known to be transcendental? - MathOverflow
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2013-05-19T10:55:40Z
http://mathoverflow.net/feeds/question/111387
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http://mathoverflow.net/questions/111387/is-ep-in-mathbbq-p-known-to-be-transcendental
Is $e^p\in\mathbb{Q}_p$ known to be transcendental?
36min
2012-11-03T16:12:41Z
2012-11-03T21:12:20Z
<p>$\sum\limits_{n=0}^{\infty}\dfrac{1}{n!}$ doesn't converge in <code>$\mathbb{Q}_p$</code>, however, $e^p:=\sum\limits_{n=0}^{\infty}\dfrac{p^n}{n!}$ does converge for <code>$p\neq 2$</code>. So my question is,</p>
<blockquote>
<p>Are $e^p\in\mathbb{Q}_p$ for $p\neq2$ (and $e^4\in\mathbb{Q}_2$) known to be non-algebraic numbers?</p>
</blockquote>
http://mathoverflow.net/questions/111387/is-ep-in-mathbbq-p-known-to-be-transcendental/111390#111390
Answer by René Pannekoek for Is $e^p\in\mathbb{Q}_p$ known to be transcendental?
René Pannekoek
2012-11-03T16:25:11Z
2012-11-03T21:12:20Z
<p>According to the last paragraph in Section 3 of the paper "Transcendental numbers in the p-adic domain" by William W. Adams (Amer. J. of Math., Vol. 88, 1966):</p>
<p><a href="http://www.jstor.org/discover/10.2307/2373193?uid=3738736&uid=2&uid=4&sid=21101389828747" rel="nofollow">http://www.jstor.org/discover/10.2307/2373193?uid=3738736&uid=2&uid=4&sid=21101389828747</a></p>
<p>the answer is yes. More specifically, they prove that if $a \in \mathbf{Q}_p$ is a non-zero element, algebraic over $\mathbf{Q}$, such that $\left| a \right| < p^{-1/(p-1)}$, then $\exp(a) \in \mathbf{Q}_p$ is transcendental over $\mathbf{Q}$ (ibid.).</p>