Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-24T00:47:54.839Z Has data issue: false hasContentIssue false

Variations on a Theme of Kronecker

Published online by Cambridge University Press:  20 November 2018

David W. Boyd*
Affiliation:
Department of Mathematics, The University of British Columbia, Vancouver, Canada V6T 1W5
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In 1857, Kronecker [10] showed that if θ1,…, θn are the roots of the polynomial P(z)= zn|cn-1+ … + cn, where c1, …, cn are integers with cn≠0, and if |θ1| ≤ 1, …, |θ1| ≤1, then θ1, …, θn are roots of unity. The proof is short and ingenious: Consider the polynomials Pm(z) whose roots are The condition on the size of the roots and the fact that the ci are integers implies that there can only be a finite number of different Pm. Thus two distinct powers of each root must coincide and this means that each root is a root of unity.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1978

References

1. Blanksby, P. E. and Montgomery, H. L., Algebraic integers near the unit circle, Acta Arith. 18 (1971), 355-369.Google Scholar
2. Boyd, D. W., Small Salem numbers, Duke Math. Jour. 44 (1977), 315-328.Google Scholar
3. Boyd, D. W., Pisot numbers and the width of meromorphic functions, privately circulated manuscript.Google Scholar
4. Boyd, D. W., Pisot and Salem numbers in intervals of the real line, Math, of Comp., (to appear in October 1978).Google Scholar
5. Cantor, D. G., On sets of algebraic integers whose remaining conjugates lie in the unit circle, Trans. Amer. Math. Soc. 105 (1962), 391-406.Google Scholar
6. Cassels, J. W. S., On a problem ofSchinzel and Zassenhaus, Jour. Math. Sci. 1 (1966), 1-8.Google Scholar
7. Chamfy, C., Fonctions méromorphes dans le cercle-unité et leurs séries de Taylor, Ann. Inst. Fourier (Grenoble) 8 (1958), 211-251.Google Scholar
8. Dobrowolski, E., On the maximal modulus of conjugates of an algebraic integer, Acta Arith (to appear).Google Scholar
9. Dufresnoy, J. and Ch. Pisot, Étude de certaines fonctions méromorphes bornées sur le cercle unité. Application à un ensemble fermé d'entiers algébriques, Ann. Se. Ec. Norm. Sup (3) 72 (1955), 6^-92.Google Scholar
10. Kronecker, L., Zwei sàtze ùber gleichungen mit Ganzzahligen coefficienten, J. fur Reine und Angew. Math. 53 (1857), 173-175.Google Scholar
11. Lehmer, D. H., Factorization of certain cyclotomic functions, Ann. Math. (2) 34 (1933), 461-479.Google Scholar
12. Salem, R., A remarkable class of algebraic integers. Proof of a conjecture of Vijayaraghavan, Duke Math. Jour. 11 (1944), 103-108.Google Scholar
13. Salem, R., Power series with integral coefficients, Duke Math. Jour. 12 (1945), 153-172.Google Scholar
14. Schinzel, A. and Zassenhaus, H., A refinement of two theorems of Kronecker, Mich. Math. Jour. 12 (1965), 81-85.Google Scholar
15. Siegel, C. L., Algebraic integers whose conjugates lie in the unit circle, Duke Math. Jour. 11 (1944), 597-602.Google Scholar
16. Smyth, C. J., On the product of the conjugates outside the unit circle of an algebraic integer, Bull. Lond. Math. Soc. 3 (1971), 169-175.Google Scholar
17. Stewart, C. L., Algebraic integers whose conjugates lie near the unit circle, Bull. Soc. Math. France, (to appear).Google Scholar