Solving conics over function fields

Mark van Hoeij[1]; John Cremona[2]

  • [1] Department of Mathematics Florida State University Tallahassee, FL 32306-3027, USA
  • [2] School of Mathematical Sciences University of Nottingham University Park, Nottingham, NG7 2RD, UK

Journal de Théorie des Nombres de Bordeaux (2006)

  • Volume: 18, Issue: 3, page 595-606
  • ISSN: 1246-7405

Abstract

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Let F be a field whose characteristic is not  2 and K = F ( t ) . We give a simple algorithm to find, given a , b , c K * , a nontrivial solution in  K (if it exists) to the equation a X 2 + b Y 2 + c Z 2 = 0 . The algorithm requires, in certain cases, the solution of a similar equation with coefficients in F ; hence we obtain a recursive algorithm for solving diagonal conics over ( t 1 , , t n ) (using existing algorithms for such equations over  ) and over 𝔽 q ( t 1 , , t n ) .

How to cite

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van Hoeij, Mark, and Cremona, John. "Solving conics over function fields." Journal de Théorie des Nombres de Bordeaux 18.3 (2006): 595-606. <http://eudml.org/doc/249634>.

@article{vanHoeij2006,
abstract = {Let $F$ be a field whose characteristic is not $2$ and $K = F(t)$. We give a simple algorithm to find, given $a,b,c \in K^*$, a nontrivial solution in $K$ (if it exists) to the equation $aX^2 + bY^2 + cZ^2 = 0$. The algorithm requires, in certain cases, the solution of a similar equation with coefficients in $F$; hence we obtain a recursive algorithm for solving diagonal conics over $\mathbb\{Q\}(t_1,\dots ,t_n)$ (using existing algorithms for such equations over $\mathbb\{Q\}$) and over $\{\mathbb\{F\}\}_q(t_1,\dots ,t_n)$.},
affiliation = {Department of Mathematics Florida State University Tallahassee, FL 32306-3027, USA; School of Mathematical Sciences University of Nottingham University Park, Nottingham, NG7 2RD, UK},
author = {van Hoeij, Mark, Cremona, John},
journal = {Journal de Théorie des Nombres de Bordeaux},
keywords = {conic; solubility certificate; reduced term},
language = {eng},
number = {3},
pages = {595-606},
publisher = {Université Bordeaux 1},
title = {Solving conics over function fields},
url = {http://eudml.org/doc/249634},
volume = {18},
year = {2006},
}

TY - JOUR
AU - van Hoeij, Mark
AU - Cremona, John
TI - Solving conics over function fields
JO - Journal de Théorie des Nombres de Bordeaux
PY - 2006
PB - Université Bordeaux 1
VL - 18
IS - 3
SP - 595
EP - 606
AB - Let $F$ be a field whose characteristic is not $2$ and $K = F(t)$. We give a simple algorithm to find, given $a,b,c \in K^*$, a nontrivial solution in $K$ (if it exists) to the equation $aX^2 + bY^2 + cZ^2 = 0$. The algorithm requires, in certain cases, the solution of a similar equation with coefficients in $F$; hence we obtain a recursive algorithm for solving diagonal conics over $\mathbb{Q}(t_1,\dots ,t_n)$ (using existing algorithms for such equations over $\mathbb{Q}$) and over ${\mathbb{F}}_q(t_1,\dots ,t_n)$.
LA - eng
KW - conic; solubility certificate; reduced term
UR - http://eudml.org/doc/249634
ER -

References

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  1. T. Cochrane, P. Mitchell, Small solutions of the Legendre equation. J. Number Theory 70 (1998), no. 1, pp. 62–66. Zbl0908.11012MR1619944
  2. J. Cremona, D. Rusin, Efficient solution of rational conics. Math. Comp. 72 (2003), no. 243, pp. 1417–1441. Zbl1022.11031MR1972744
  3. C. F. Gauss, Disquisitiones Arithmeticae. Springer-Verlag, 1986. Zbl0585.10001MR837656
  4. A. K. Lenstra, H. W. Lenstra, Jr., L. Lovász, Factoring polynomials with rational coefficients. Math. Ann. 261 (1982), no. 4, pp. 515–534. Zbl0488.12001MR682664
  5. W. Bosma, J. Cannon, C. Playoust, The Magma algebra system. I. The user language. J. Symbolic Comput., 24 (1997), 235–265. Computational algebra and number theory (London, 1993). See also http://magma.maths.usyd.edu.au/magma/. Zbl0898.68039MR1484478
  6. M. B. Monagan, K. O. Geddes, K. M. Heal, G. Labahn, S. M. Vorkoetter, J. McCarron, Maple 6 Programming Guide. Waterloo Maple Inc. (Waterloo, Canada, 2000). Zbl0877.68070
  7. M. Reid, Chapters on Algebraic Surfaces, Chapter C: Guide to the classification of surfaces. In J. Kollár (Ed.), IAS/Park City lecture notes series 3 (1993), AMS, Providence R.I., 1997, 1–154. See also www.maths.warwick.ac.uk/~miles/surf/ParkC/chC.ps. Zbl0910.14016MR1442522
  8. J. Schicho, Rational parametrization of real algebraic surfaces. Proceedings of the 1998 International Symposium on Symbolic and Algebraic Computation (Rostock), ACM, New York, 1998, 302–308. Zbl0939.14034MR1805193
  9. J. Schicho, Proper parametrization of surfaces with a rational pencil. Proceedings of the 2000 International Symposium on Symbolic and Algebraic Computation (St. Andrews), ACM, New York, 2000, 292–300. Zbl1326.68369MR1805132
  10. D. Simon, Solving quadratic equations using reduced unimodular quadratic forms. Math. Comp. 74 (2005), no. 251, pp. 1531–1543. Zbl1078.11072MR2137016
  11. C. van de Woestijne, Surface Parametrisation without Diagonalisation. Proceedings of the 2006 International Symposium on Symbolic and Algebraic Computation (Genoa), ACM, New York, 2006, 340–344. MR2289140

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