NYJM Logo

New York Journal of Mathematics
Volume 26 (2020), 1145-1154

  

Vítězslav Kala and Pavlo Yatsyna

Sums of squares in S-integers

view    print


Published: October 5, 2020.
Keywords: number field, totally real, S-integers, sum of squares, Pythagoras number.
Subject: 11E25,11E12,11R11.

Abstract
In totally real number fields, we characterize the rings of S-integers (obtained by inverting a rational integer m) such that all their totally positive elements are represented as a sum of squares. We further obtain partial answers to the question: when are all the totally positive algebraic integers that are divisible by m represented as a sum of squares?

Acknowledgements

The authors were supported by projects PRIMUS/20/SCI/002 (V.K., P.Y.) and UNCE/SCI/022 (V.K.) from Charles University.


Author information

Vítězslav Kala:
Charles University
Faculty of Mathematics and Physics
Department of Algebra
Sokolovska 83, 18600 Praha 8, Czech Republic

kala@karlin.mff.cuni.cz

Pavlo Yatsyna:
Charles University
Faculty of Mathematics and Physics
Department of Algebra
Sokolovska 83, 18600 Praha 8, Czech Republic

yatsyna@karlin.mff.cuni.cz