Title: | On ternary quadratic forms over the rational numbers (English) |
Author: | Jafari, Amir |
Author: | Rostamkhani, Farhood |
Language: | English |
Journal: | Czechoslovak Mathematical Journal |
ISSN: | 0011-4642 (print) |
ISSN: | 1572-9141 (online) |
Volume: | 72 |
Issue: | 4 |
Year: | 2022 |
Pages: | 1105-1119 |
Summary lang: | English |
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Category: | math |
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Summary: | For a ternary quadratic form over the rational numbers, we characterize the set of rational numbers represented by that form over the rational numbers. Consequently, we reprove the classical fact that any positive definite integral ternary quadratic form must fail to represent infinitely many positive integers over the rational numbers. Our proof uses only the quadratic reciprocity law and the Hasse-Minkowski theorem, and is elementary. (English) |
Keyword: | ternary quadratic forms |
Keyword: | Gauss reciprocity law |
Keyword: | Hasse-Minkowski theorem |
MSC: | 11A15 |
MSC: | 11D09 |
idZBL: | Zbl 07655786 |
idMR: | MR4517599 |
DOI: | 10.21136/CMJ.2022.0359-21 |
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Date available: | 2022-11-28T11:39:31Z |
Last updated: | 2023-04-11 |
Stable URL: | http://hdl.handle.net/10338.dmlcz/151133 |
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Reference: | [1] Albert, A. A.: The integers represented by sets of ternary quadratic forms.Am. J. Math. 55 (1933), 274-292. Zbl 0006.29004, MR 1506964, 10.2307/2371130 |
Reference: | [2] Conway, J. H.: The Sensual (Quadratic) Form.The Carus Mathematical Monographs 26. Mathematical Association of America, Washington (1997). Zbl 0885.11002, MR 1478672, 10.5948/UPO9781614440253 |
Reference: | [3] Cox, D. A.: Primes of the Form $x^2+ny^2$: Fermat, Class Field Theory, and Complex Multiplication.Pure and Applied Mathematics. A Wiley Series of Texts, Monographs, and Tracts. John Wiley & Sons, Hoboken (2013). Zbl 1275.11002, MR 3236783, 10.1002/9781118400722 |
Reference: | [4] Dickson, L. E.: Integers represented by positive ternary quadratic forms.Bull. Am. Math. Soc. 33 (1927), 63-70 \99999JFM99999 53.0133.04. MR 1561323, 10.1090/S0002-9904-1927-04312-9 |
Reference: | [5] Doyle, G., Williams, K. S.: A positive-definite ternary quadratic form does not represent all positive integers.Integers 17 (2017), Article ID A.41, 19 pages. Zbl 1412.11065, MR 3708292 |
Reference: | [6] Duke, W., Schulze-Pillot, R.: Representations of integers by positive ternary quadratic forms and equidistribution of lattice points on ellipsoids.Invent. Math. 99 (1990), 49-57. Zbl 0692.10020, MR 1029390, 10.1007/BF01234411 |
Reference: | [7] Flath, D. E.: Introduction to Number Theory.AMS, Providence (2018). Zbl 1400.11001, MR 3837147, 10.1090/chel/384.H |
Reference: | [8] Gupta, H.: Some idiosyncratic numbers of Ramanujan.Proc. Indian Acad. Sci., Sect. A 13 (1941), 519-520. Zbl 0063.01797, MR 0004816, 10.1007/BF03049015 |
Reference: | [9] Jones, B. W., Pall, G.: Regular and semi-regular positive ternary quadratic forms.Acta Math. 70 (1939), 165-191. Zbl 0020.10701, MR 1555447, 10.1007/BF02547347 |
Reference: | [10] Kaplansky, I.: Ternary positive quadratic forms that represent all odd positive integers.Acta Arith. 70 (1995), 209-214. Zbl 0817.11024, MR 1322563, 10.4064/aa-70-3-209-214 |
Reference: | [11] Kaplansky, I.: Linear Algebra and Geometry: A Second Course.Dover Publications, Mineola (2003). Zbl 1040.15001, MR 2001037 |
Reference: | [12] Lebesgue, V. A.: Tout nombre impair est la somme de quatre carrés dont deux sont égaux.J. Math. Pures Appl. (2) 2 (1857), 149-152 French. |
Reference: | [13] Legendre, A. M.: Essai sur la théorie des nombres.Duprat, Paris (1798), French. Zbl 1395.11003, MR 2859036 |
Reference: | [14] Mordell, L. J.: The condition for integer solutions of $ax^2 +by^2 +cz^2 +dt^2 = 0$.J. Reine Angew. Math. 164 (1931), 40-49. Zbl 0001.12001, MR 1581249, 10.1515/crll.1931.164.40 |
Reference: | [15] Mordell, L. J.: Note on the diophantine equation $ax^2 +by^2 +cz^2 +dt^2 = 0$.Bull. Am. Math. Soc. 38 (1932), 277-282. Zbl 0004.20004, MR 1562374, 10.1090/S0002-9904-1932-05373-3 |
Reference: | [16] Ono, K., Soundararajan, K.: Ramanujan's ternary quadratic form.Invent. Math. 130 (1997), 415-454. Zbl 0930.11022, MR 1483991, 10.1007/s002220050191 |
Reference: | [17] Ramanujan, S.: On the expression of a number in the form $ax^2 + by^2 + cz^2 + du^2$.Proc. Camb. Philos. Soc. 19 (1917), 11-21 \99999JFM99999 46.0240.01. |
Reference: | [18] Serre, J.-P.: A Course in Arithmetic.Graduate Texts in Mathematics 7. Springer, New York (1973). Zbl 0256.12001, MR 0344216, 10.1007/978-1-4684-9884-4 |
Reference: | [19] Sun, Z.-W.: On universal sums of polygonal numbers.Sci. China, Math. 58 (2015), 1367-1396. Zbl 1348.11031, MR 3353977, 10.1007/s11425-015-4994-4 |
Reference: | [20] Wu, H.-L., Sun, Z.-W.: Arithmetic progressions represented by diagonal ternary quadratic forms.Available at https://arxiv.org/abs/1811.05855v1 (2018), 16 pages. |
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