Abstract
A polynomial f (multivariate over a field) is decomposable if \({f=g \circ h}\) with g univariate of degree at least 2. We determine the dimension (over an algebraically closed field) of the set of decomposables, and an approximation to their number over a finite field. The relative error in our approximations is exponentially decaying in the input size.
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Alonso, C., Gutierrez, J., Recio, T.: A rational function decomposition algorithm by near-separated polynomials. J. Symb. Comput. 19, 527–544. ISSN 0747-7171. http://dx.doi.org/10.1006/jsco.1995.1030 (1995)
Bodin A., Dèbes P., Najib S.: Indecomposable polynomials and their spectrum. Acta Arith. 139(1), 79–100 (2009)
Carlitz L.: On factorable polynomials in several indeterminates. Duke Math. J. 2, 660–670 (1936)
Carlitz L.: The distribution of irreducible polynomials in several indeterminates. Ill. J. Math. 7, 371–375 (1963)
Carlitz L.: The distribution of irreducible polynomials in several indeterminates II. Can. J. Math. 17, 261–266 (1965)
Chèze, G.: Nearly optimal algorithms for the decomposition of multivariate rational functions and the extended Lüroth’s theorem. J. Complex. 26(4), 344–363. http://dx.doi.org/10.1016/j.physletb.2003.10.071 (2010)
Cohen S.: The distribution of irreducible polynomials in several indeterminates over a finite field. Proc. Edinb. Math. Soc. 16, 1–17 (1968)
Dickerson, M.: Polynomial decomposition algorithms for multivariate polynomials. Technical Report 87-826, Department of Computer Science, Cornell University, Ithaca, NY (1987)
Faugère, J.-C., Perret, L.: High order derivatives and decomposition of multivariate polynomials. In: Álvar, I., Gutiérrez, J. (eds.) Extended Abstracts of the Second Workshop on Mathematical Cryptology WmC 08, pp. 90–93. Ibeas, http://grupos.unican.es/amac/wmc-2008/ (2008)
von zur Gathen, J.: Functional decomposition of polynomials: the tame case. J. Symb. Comput. 9, 281–299. http://dx.doi.org/10.1016/S0747-7171(08)80014-4 (1990)
von zur Gathen, J.: Counting decomposable multivariate polynomials. Preprint, p. 21. http://arxiv.org/abs/0811.4726 (2008a)
von zur Gathen, J.: Counting decomposable univariate polynomials. Preprint, p. 93. http://arxiv.org/abs/0901.0054 (2008b). Extended abstract see von zur Gahen (2009)
von zur Gathen, J.: Counting reducible and singular bivariate polynomials. Finite Fields Their Appl. 14(4), 944–978. http://dx.doi.org/10.1016/j.ffa.2008.05.005 (2008c). Extended abstract in Proceedings of the 2007 International Symposium on Symbolic and Algebraic Computation ISSAC2007, Waterloo, Ontario, Canada, pp. 369–376 (2007)
von zur Gathen, J.: The number of decomposable univariate polynomials—extended abstract. In: May, J.P. (ed.) Proceedings of the 2009 International Symposium on Symbolic and Algebraic Computation ISSAC2009, Seoul, Korea, pp. 359–366. ISBN 978-1-60558-609-0. Preprint (2008) at http://arxiv.org/abs/0901.0054 (2009)
von zur Gathen, J., Giesbrecht, M., Ziegler, K.: Composition collisions and projective polynomials. Statement of results. In: Watt, S. (ed.) Proceedings of the 2010 International Symposium on Symbolic and Algebraic Computation ISSAC2010, Munich, Germany, pp. 123–130. ACM Press, New York. Preprint available at http://arxiv.org/abs/1005.1087 (2010a)
von zur Gathen, J., Gutierrez, J., Rubio, R.: Multivariate polynomial decomposition. Appl. Algebra Eng. Commun. Comput. 14, 11–31 (2003). http://dx.doi.org/10.1007/s00200-003-0122-8. Extended abstract in Proceedings of the Second Workshop on Computer Algebra in Scientific Computing, CASC ’99, München, Germany, pp. 463–478 (1999)
von zur Gathen, J., Viola, A., Ziegler, K.: Counting reducible, powerful, and relatively irreducible multivariate polynomials over finite fields (Extended Abstract). In: López-Ortiz, A. (ed.) Proceedings of LATIN 2010, Oaxaca, Mexico, volume 6034 of Lecture Notes in Computer Science. pp. 243–254. Springer, Berlin,. ISBN 978-3-642-12199-9. ISSN 0302-9743 (Print) 1611-3349 (Online). http://dx.doi.org/10.1007/978-3-642-12200-2_23 (2010b)
Giesbrecht, M.W.: Complexity results on the functional decomposition of polynomials. Technical Report 209/88, University of Toronto, Department of Computer Science, Toronto, ON, Canada. Available as http://arxiv.org/abs/1004.5433 (1988)
Gutierrez, J., Rubio, R., Sevilla, D.: Unirational fields of transcendence degree one and functional decomposition. In: Mourrain, B. (ed.) ISSAC01, pp. 167–174. ACM Press, New York. ISBN 1-58113-417-7. http://dx.doi.org/10.1145/384101.384124 (2001)
Moulin Ollagnier, J.: Algebraic closure of a rational function. Qual. Theory Dyn. Syst. 5(2), 285–300. ISSN 1575-5460 (Print) 1662-3592 (Online). http://dx.doi.org/10.1007/BF02972683 (2004)
Zippel, R.: Rational function decomposition. In: Watt, S.M. (ed.) Proceedings of the 1991 International Symposium on Symbolic and Algebraic Computation ISSAC ’91. Bonn, Germany, pp. 1–6. ACM Press, Bonn, ISBN 0-89791-437-6 (1991)
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von zur Gathen, J. Counting decomposable multivariate polynomials. AAECC 22, 165–185 (2011). https://doi.org/10.1007/s00200-011-0141-9
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DOI: https://doi.org/10.1007/s00200-011-0141-9