View source for Lindemann theorem

The [[Exponential function|exponential function]] <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590101.png" /> takes transcendental values (cf. [[Transcendental number|Transcendental number]]) at algebraic points <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590102.png" /> (cf. [[Algebraic number|Algebraic number]]); proved by F. Lindemann in 1882. The following more general assertion, which was stated without proof by Lindemann and was proved by K. Weierstrass in 1885, is known as the Lindemann–Weierstrass theorem.

Let <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590103.png" /> be non-zero algebraic numbers and let <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590104.png" /> be pairwise distinct algebraic numbers; then

<table class="eq" style="width:100%;"> <tr><td valign="top" style="width:94%;text-align:center;"><img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590105.png" /></td> </tr></table>

This assertion is equivalent to the following: If <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590106.png" /> are algebraic numbers, linearly independent over the field of rational numbers, then the numbers <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590107.png" /> are algebraically independent.

The method of proving Lindemann's theorem is known as the Hermite–Lindemann method. It is a development of Hermite's method by which he proved in 1873 that <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590108.png" /> is transcendental, and it is based on the application of the [[Hermite identity|Hermite identity]] to certain specially constructed polynomials.

From Lindemann's theorem one can deduce that <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l0590109.png" /> is transcendental, that the problem of squaring the circle has no solution, and also that the functions <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l05901010.png" />, <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l05901011.png" /> and <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l05901012.png" /> take transcendental values for algebraic <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l05901013.png" />, and that <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l05901014.png" /> takes transcendental values for algebraic <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/l/l059/l059010/l05901015.png" />.

====References====
<table><TR><TD valign="top">[1]</TD> <TD valign="top">  A.O. Gel'fond,   "Transcendental and algebraic numbers" , Dover, reprint  (1960)  (Translated from Russian)</TD></TR><TR><TD valign="top">[2]</TD> <TD valign="top">  N.I. Fel'dman,   A.B. Shidlovskii,   "The development and present state of the theory of transcendental numbers"  ''Russian Math. Surveys'' , '''22''' :  3  (1967)  pp. 1–79  ''Uspekhi Mat. Nauk'' , '''22''' :  3  (1967)  pp. 3–81</TD></TR></table>



====Comments====
D. Hilbert gave a simplified proof of the theorem, which was later polished by a large number of other authors, see [[#References|[a1]]]. In 1988, F. Beukers, J.P. Bézivin and Ph. Robba gave a new elementary proof, see [[#References|[a2]]].

====References====
<table><TR><TD valign="top">[a1]</TD> <TD valign="top">  A. Baker,   "Transcendental number theory" , Cambridge Univ. Press  (1975)</TD></TR><TR><TD valign="top">[a2]</TD> <TD valign="top">  F. Beukers,   J.P. Bézivin,   Ph. Robba,   "An alternative proof of the Lindemann–Weierstrass theorem"  ''Amer. Math. Monthly''  (Forthcoming (1989))</TD></TR></table>