On ternary quadratic forms over the rational numbers

التفاصيل البيبلوغرافية
العنوان: On ternary quadratic forms over the rational numbers
المؤلفون: Jafari, Amir, Rostamkhani, Farhood
سنة النشر: 2021
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - History and Overview, Mathematics - Number Theory, 11A15, 11D09
الوصف: In this note, we give an elementary proof of the following classical fact. Any positive definite ternary quadratic form over the rational numbers fails to represent infinitely many positive integers. For any ternary quadratic form (positive definite or indefinite), our method constructs certain congruence classes whose elements, up to a square factor, are the only elements not represented over the rational numbers by that form. In the case of a positive definite ternary form, we show that these classes are non-empty. This shows that the minimum number of variables in a positive definite quadratic form representing all positive integers is four. Our proof is very elementary and only uses quadratic reciprocity of Gauss.
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2109.10225
رقم الأكسشن: edsarx.2109.10225
قاعدة البيانات: arXiv