The Ramanujan Journal

, Volume 37, Issue 2, pp 243–256 | Cite as

Stability of ideal lattices from quadratic number fields

  • Lenny Fukshansky


We study semi-stable ideal lattices coming from quadratic number fields. We prove that all ideal lattices of trace type from rings of integers of imaginary quadratic number fields are semi-stable. For real quadratic fields, we demonstrate infinite families of semi-stable and unstable ideal lattices, establishing explicit conditions on the canonical basis of an ideal that ensure stability; in particular, our result implies that an ideal lattice of trace type coming from a real quadratic field is semi-stable with positive probability. We also briefly discuss the connection between stability and well-roundedness of Euclidean lattices.


Semi-stable lattices Ideal lattices Quadratic number fields 

Mathematics Subject Classification

11H06 11R11 11E16 11H55 



I would like to thank Professor Florian Luca for suggesting the proof of Lemma 2.1, as indicated above. I also thank Professors Gang Yu and David Speyer, whose comments were instrumental to the formulation of Remark 4.1. Finally, I thank the referee for many useful suggestions which improved the quality of the paper.


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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Department of MathematicsClaremont McKenna CollegeClaremontUSA

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