Hostname: page-component-848d4c4894-x24gv Total loading time: 0 Render date: 2024-05-04T00:15:32.445Z Has data issue: false hasContentIssue false

A note on the number of zeros of polynomials and exponential polynomials

Published online by Cambridge University Press:  12 March 2014

Extract

The negative solution of Hilbert's Tenth Problem brought with it a number of unsolvable Diophantine problems. Moreover, by actually providing a Diophantine characterization of recursive enumerability, the proof of the negative solution opened the door to the techniques of recursion theory. In this note, we wish to apply several recursion-theoretic facts and an improvement on the exponential Diophantine representation to refine the exponential case of a result of Davis [1972] regarding the difficulty of determining the number of zeros of a polynomial.

P, Q, etc. will denote polynomials or exponential polynomials–exactly which will be clear from the context. Let # (P) denote the number of distinct nonnegative zeros of P. Further, let C = {0,1, …,ℵ0} be the set of possible values of # (P). For A ⊆ C, we define A * to be

With this notation, Davis' result reads:

Theorem 0.1 (DAVIS). A* is recursive iff A = ∅ or A = C.

The refinement we will prove is:

Theorem 0.2 (Exponential Case). A * is r.e. iff A = ∅ or A = {c: c ≥ a: m} for some finite m.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1977

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[A] Adleman, L. and Manders, K., Computational complexity of decision procedures for polynomials (to appear).Google Scholar
[1972] Davis, M., On the number of solutions of Diophantine equations, Proceedings of the American Mathematical Society, vol. 35, pp. 552554.CrossRefGoogle Scholar
[1973] Davis, M., Speed-up theorems and Diophantine equations, Courant Computer Science Symposium 7: Computational Complexity (Rustin, R., Editor), Algorithmes Press, N.Y.Google Scholar
[1966] Dekker, J. C. E., Les fonctions combinatoires et les isols, Gauthier-Villars, Paris.Google Scholar
[1974] Matiyasevich, Yu. V., Sushchestvovanie neeffektiviziruemikh otsenok v teorii ekzponentsial'no diofantovikh, Zapiski Naučnyh Seminarov Leningradskogo Otdelenija Matematičeskogo Instituta im. V. A. Steklova Academii Nauk SSSR, vol. 40, pp. 7793.Google Scholar
[1971] Robinson, J., Hilbert's tenth problem, 1969 Institute on number theory (Lewis, D. J., Editor), American Mathematical Society, Providence, R.I., 1971.Google Scholar
[1967] Rogers, H. Jr., Theory of recursive functions and effective computability, McGraw-Hill, N.Y.Google Scholar