Skip to main content
Log in

Sums of units in function fields

  • Published:
Monatshefte für Mathematik Aims and scope Submit manuscript

Abstract

Let R be the ring of S-integers of an algebraic function field (in one variable) over a perfect field, where S is finite and not empty. It is shown that for every positive integer N there exist elements of R that can not be written as a sum of at most N units. Moreover, all quadratic global function fields whose rings of integers are generated by their units are determined.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Ashrafi N., Vámos P.: On the unit sum number of some rings. Q. J. Math. 56(1), 1–12 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  2. Belcher P.: Integers expressible as sums of distinct units. Bull. Lond. Math. Soc. 6, 66–68 (1974)

    Article  MathSciNet  MATH  Google Scholar 

  3. Belcher, P.: A test for integers being sums of distinct units applied to cubic fields. J. Lond. Math. Soc. (2) 12(2), 141–148 (1975/1976)

    Google Scholar 

  4. Brownawell W.D., Masser D.W.: Vanishing sums in function fields. Math. Proc. Camb. Philos. Soc. 100(3), 427–434 (1986)

    Article  MathSciNet  MATH  Google Scholar 

  5. Filipin A., Tichy R.F., Ziegler V.: The additive unit structure of pure quartic complex fields. Funct. Approx. Comment. Math. 39(1), 113–131 (2008)

    MathSciNet  MATH  Google Scholar 

  6. Filipin A., Tichy R.F., Ziegler V.: On the quantitative unit sum number problem—an application of the subspace theorem. Acta Arith. 133(4), 297–308 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  7. Fuchs C., Tichy R.F., Ziegler V.: On quantitative aspects of the unit sum number problem. Arch. Math. 93, 259–268 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  8. Goldsmith B., Pabst S., Scott A.: Unit sum numbers of rings and modules. Q. J. Math. 49(195), 331–344 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  9. Hajdu L.: Arithmetic progressions in linear combinations of S-units. Period. Math. Hung. 54(2), 175–181 (2007)

    MathSciNet  MATH  Google Scholar 

  10. Hasse H.: Theorie der relativ-zyklischen algebraischen Funktionenkörper, insbesondere bei endlichem Konstantenkörper. J. reine angew. Math. 172, 37–54 (1935)

    Article  Google Scholar 

  11. Jacobson B.: Sums of distinct divisors and sums of distinct units. Proc. Am. Math. Soc. 15, 179–183 (1964)

    Article  MATH  Google Scholar 

  12. Jarden M., Narkiewicz W.: On sums of units. Monatsh. Math. 150(4), 327–332 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  13. Le Brigand, D.: Real quadratic extensions of the rational function field in characteristic two. In: Arithmetic, Geometry and Coding Theory (AGCT 2003), Sémin. Congr., vol. 11, pp. 143–169. Soc. Math. France, Paris (2005)

  14. Mason R.C.: Norm form equations. I. J. Number Theory 22(2), 190–207 (1986)

    Article  MathSciNet  MATH  Google Scholar 

  15. Mason R.C.: Norm form equations. III. Positive characteristic. Math. Proc. Camb. Philos. Soc. 99(3), 409–423 (1986)

    Article  MATH  Google Scholar 

  16. Rosen M.: Number Theory in Function Fields, Graduate Texts in Mathematics. Springer, New York (2002)

    Google Scholar 

  17. Śliwa J.: Sums of distinct units. Bull. Acad. Pol. Sci. 22, 11–13 (1974)

    MATH  Google Scholar 

  18. Stichtenoth H.: Algebraic Function Fields and Codes. Universitext. Springer, Berlin (1993)

    Google Scholar 

  19. Tichy R.F., Ziegler V.: Units generating the ring of integers of complex cubic fields. Colloq. Math. 109(1), 71–83 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  20. Zelinsky D.: Every linear transformation is a sum of nonsingular ones. Proc. Am. Math. Soc. 5, 627–630 (1954)

    Article  MathSciNet  MATH  Google Scholar 

  21. Ziegler V.: The additive unit structure of complex biquadratic fields. Glas. Mat. 43(63)(2), 293–307 (2008)

    Article  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Christopher Frei.

Additional information

Communicated by U. Zannier.

C. Frei is supported by the Austrian Science Foundation (FWF) project S9611-N23.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Frei, C. Sums of units in function fields. Monatsh Math 164, 39–54 (2011). https://doi.org/10.1007/s00605-010-0219-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00605-010-0219-7

Keywords

Mathematics Subject Classification (2000)

Navigation