On the complexity of computing integral bases of function fields

Let $\mathcal{C}$ be a plane curve given by an equation $f(x,y)=0$ with $f\in K[x][y]$ a monic squarefree polynomial. We study the problem of computing an integral basis of the algebraic function field $K(\mathcal{C})$ and give new complexity bounds for three known algorithms dealing with this problem. For each algorithm, we study its subroutines and, when it is possible, we modify or replace them so as to take advantage of faster primitives. Then, we combine complexity results to derive an overall complexity estimate for each algorithm. In particular, we modify an algorithm due to Bohm et al. and achieve a quasi-optimal runtime.

[1]  Florian Hess,et al.  Computing Riemann-Roch Spaces in Algebraic Function Fields and Related Topics , 2002, J. Symb. Comput..

[2]  C. Hoffmann Algebraic curves , 1988 .

[3]  J. Niel de Beaudrap,et al.  On the complexity of solving linear congruences and computing nullspaces modulo a constant , 2012, Chic. J. Theor. Comput. Sci..

[4]  James H. Davenport,et al.  On the Integration of Algebraic Functions , 1979, Lecture Notes in Computer Science.

[5]  Hans Zassenhaus EIN ALGORITHMUS ZUR BERECHNUNG EINER MINIMALBASIS UBER GEGEBENER , 1967 .

[6]  D. Duval Rational Puiseux expansions , 1989 .

[7]  Vincent Neiger,et al.  Fast Computation of Shifted Popov Forms of Polynomial Matrices via Systems of Modular Polynomial Equations , 2016, ISSAC.

[8]  Vikraman Arvind,et al.  The Complexity of Solving Linear Equations over a Finite Ring , 2005, STACS.

[9]  Gerhard Pfister,et al.  Computing integral bases via localization and Hensel lifting , 2015, J. Symb. Comput..

[10]  Adrien Poteaux,et al.  Computing Puiseux series: a fast divide and conquer algorithm , 2017, Annales Henri Lebesgue.

[11]  Jens-Dietrich Bauch Computation of Integral Bases , 2015, 1507.04058.

[12]  George Labahn,et al.  Fast, deterministic computation of the Hermite normal form and determinant of a polynomial matrix , 2017, J. Complex..

[13]  Éric Schost,et al.  A Fast Algorithm for Computing the Truncated Resultant , 2016, ISSAC.

[14]  B. Salvy,et al.  Algorithmes Efficaces en Calcul Formel , 2017 .

[15]  Andreas Steenpaß,et al.  Parallel algorithms for normalization , 2011, J. Symb. Comput..

[16]  Dominique Duval,et al.  About a New Method for Computing in Algebraic Number Fields , 1985, European Conference on Computer Algebra.

[18]  Mark van Hoeij,et al.  An Algorithm for Computing an Integral Basis in an Algebraic Function Field , 1994, J. Symb. Comput..

[19]  François Le Gall,et al.  Powers of tensors and fast matrix multiplication , 2014, ISSAC.

[20]  Gerhard Pfister,et al.  Local analytic geometry - basic theory and applications , 2000, Advanced lectures in mathematics.

[21]  Christopher Umans,et al.  Fast Polynomial Factorization and Modular Composition , 2011, SIAM J. Comput..