Abstract
We develop a new method that improves the efficiency of equation-by-equation homotopy continuation methods for solving polynomial systems. Our method is based on a novel geometric construction and reduces the total number of homotopy paths that must be numerically continued. These improvements may be applied to the basic algorithms of numerical algebraic geometry in the settings of both projective and multiprojective varieties. Our computational experiments demonstrate significant savings obtained on several benchmark systems. We also present an extended case study on maximum likelihood estimation for rank-constrained symmetric \(n\times n\) matrices, in which multiprojective u-generation allows us to complete the list of ML degrees for \(n\le 6.\)
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In this paper, we shall gloss over many details of how homotopy tracking is accomplished in practice and issues arising from the need to use approximations of points. For this, we refer the reader to introductory chapters of [31].
Here, we use the fact that \(\pi \) is an open map, which follows from [27, 3.10].
We use “general” throughout this article to mean “avoiding some proper Zariski closed set.” Here, this exceptional set has a simple description: \(\mathbb {V}(L)\) needs to be outside the set of subspaces in the Grassmannian \(\textrm{Gr}(n-c,n)\) that do not intersect X regularly. However, the randomized methods of homotopy continuation do not rely on knowing the exceptional set description: we use “general” without aiming to provide such a description later on (e.g., in Remark 2.5).
The constant \(\gamma \) needs to avoid a real hypersurface (in fact, a union lines through the origin) in \(\mathbb {R}^2\cong \mathbb {C}\) containing “bad” choices: a choice of \(\gamma \) is “bad” if the homotopy paths of (3) cross.
References
J. Backelin and R. Fröberg. How we proved that there are exactly 924 cyclic 7-roots. In S. M. Watt, editor, Proceedings of the 1991 International Symposium on Symbolic and Algebraic Computation, ISSAC ’91, Bonn, Germany, July 15-17, 1991, pages 103–111. ACM, 1991
D. J. Bates, J. D. Hauenstein, A. J. Sommese, and C. W. Wampler. Bertini: Software for Numerical Algebraic Geometry. Available at bertini.nd.edu with permanent doi: dx.doi.org/10.7274/R0H41PB5
D. J. Bates, J. D. Hauenstein, A. J. Sommese, and C. W. Wampler. Numerically solving polynomial systems with Bertini, volume 25 of Software, Environments, and Tools. Society for Industrial and Applied Mathematics (SIAM), Philadelphia, PA, 2013
Bernstein, D.N.: The number of roots of a system of equations. Funkcional. Anal. i Priložen. 9(3), 1–4 (1975)
P. Breiding and S. Timme. Homotopycontinuation.jl: A package for homotopy continuation in Julia. In Mathematical Software – ICMS 2018, pages 458–465. Springer International Publishing, 2018
Brysiewicz, T., Rodriguez, J.I., Sottile, F., Yahl, T.: Decomposable sparse polynomial systems. J. Softw. Algebra Geom. 11(1), 53–59 (2021)
T. Chen, T.-L. Lee, and T.-Y. Li. Hom4ps-3: a parallel numerical solver for systems of polynomial equations based on polyhedral homotopy continuation methods. In International Congress on Mathematical Software, pages 183–190. Springer, 2014
Draisma, J., Rodriguez, J.: Maximum likelihood duality for determinantal varieties. Int. Math. Res. Not. IMRN 20, 5648–5666 (2014)
Duff, T., Hill, C., Jensen, A., Lee, K., Leykin, A., Sommars, J.: Solving polynomial systems via homotopy continuation and monodromy. IMA J. Numer. Anal. 39(3), 1421–1446 (2019)
Giusti, M., Lecerf, G., Salvy, B.: A Gröbner free alternative for polynomial system solving. J. Complexity 17(1), 154–211 (2001)
D. R. Grayson and M. E. Stillman. Macaulay2, a software sy,stem for research in algebraic geometry. Available at http://www.math.uiuc.edu/Macaulay2/
Hauenstein, J., Rodriguez, J.I., Sturmfels, B.: Maximum likelihood for matrices with rank constraints. J. Algebr. Stat. 5(1), 18–38 (2014)
Hauenstein, J.D., Leykin, A., Rodriguez, J.I., Sottile, F.: A numerical toolkit for multiprojective varieties. Math. Comp. 90(327), 413–440 (2021)
Hauenstein, J.D., Rodriguez, J.I.: Multiprojective witness sets and a trace test. Adv. Geom. 20(3), 297–318 (2020)
Hauenstein, J.D., Sommese, A.J.: Witness sets of projections. Appl. Math. Comput. 217(7), 3349–3354 (2010)
Hauenstein, J.D., Sommese, A.J., Wampler, C.W.: Regeneration homotopies for solving systems of polynomials. Math. Comp. 80(273), 345–377 (2011)
Hauenstein, J.D., Sommese, A.J., Wampler, C.W.: Regenerative cascade homotopies for solving polynomial systems. Appl. Math. Comput. 218(4), 1240–1246 (2011)
Hauenstein, J.D., Wampler, C.W.: Unification and extension of intersection algorithms in numerical algebraic geometry. Appl. Math. Comput. 293, 226–243 (2017)
Huber, B., Sturmfels, B.: A polyhedral method for solving sparse polynomial systems. Math. Comp. 64(212), 1541–1555 (1995)
A. N. Jensen. Gfan, a software system for Gröbner fans and tropical varieties. Available at http://home.imf.au.dk/jensen/software/gfan/gfan.html
A. N. Jensen. Tropical homotopy continuation. arXiv preprint arXiv:1601.02818, 2016
S. Katsura. Spin glass problem by the method of integral equation of the effective field. New Trends in Magnetism, pages 110–121, 1990
Kubjas, K., Robeva, E., Sturmfels, B.: Fixed points EM algorithm and nonnegative rank boundaries. Ann. Statist. 43(1), 422–461 (2015)
Leykin, A.: Numerical algebraic geometry. Journal of Software for Algebra and Geometry 3(1), 5–10 (2011)
A. Leykin, J. Verschelde, and A. Zhao. Higher-order deflation for polynomial systems with isolated singular solutions. In Algorithms in algebraic geometry, volume 146 of IMA Vol. Math. Appl., pages 79–97. Springer, New York, 2008
A. Martín del Campo and J. I. Rodriguez. Critical points via monodromy and local methods. J. Symbolic Comput., 79(part 3):559–574, 2017
D. Mumford. Stability of projective varieties. Enseign. Math. (2), 23(1-2):39–110, 1977
A. J. Sommese and J. Verschelde. Numerical homotopies to compute generic points on positive dimensional algebraic sets. journal of complexity, 16(3):572–602, 2000
A. J. Sommese, J. Verschelde, and C. W. Wampler. Symmetric functions applied to decomposing solution sets of polynomial systems. SIAM J. Numer. Anal., 40(6):2026–2046 (2003), 2002
A. J. Sommese, J. Verschelde, and C. W. Wampler. Solving polynomial systems equation by equation. In Algorithms in algebraic geometry, volume 146 of IMA Vol. Math. Appl., pages 133–152. Springer, New York, 2008
A. J. Sommese and C. W. Wampler, II. The numerical solution of systems of polynomials. World Scientific Publishing Co. Pte. Ltd., Hackensack, NJ, 2005. Arising in engineering and science
F. Sottile. General witness sets for numerical algebraic geometry. In Proceedings of the 45th International Symposium on Symbolic and Algebraic Computation, ISSAC ’20, page 418–425, New York, NY, USA, 2020. Association for Computing Machinery
S. Sullivant. Algebraic statistics, volume 194 of Graduate Studies in Mathematics. American Mathematical Society, Providence, RI, 2018
Telen, S., Van Barel, M., Verschelde, J.: A robust numerical path tracking algorithm for polynomial homotopy continuation. SIAM J. Sci. Comput. 42(6), A3610–A3637 (2020)
Verschelde, J.: Algorithm 795: Phcpack: a general-purpose solver for polynomial systems by homotopy continuation. ACM Transactions on Mathematical Software 25(2), 251–276 (1999)
Funding
T.D. acknowledges support from an NSF Mathematical Sciences Postdoctoral Research Fellowship (DMS-2103310). Research of A.L. is supported in part by NSF DMS-2001267. Research of J.I.R. is supported by the Office of the Vice Chancellor for Research and Graduate Education at U.W. Madison with funding from the Wisconsin Alumni Research Foundation.
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All authors thank the Institute for Mathematics and its Applications in Minneapolis for hosting them for a series of “SageMath and Macaulay2” meetings in 2019-2020 where the ideas of this work were born.
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Timothy Duff: https://timduff35.github.io/timduff35/
Anton Leykin: https://antonleykin.math.gatech.edu/index.html
Jose Israel Rodriguez: https://sites.google.com/wisc.edu/jose/.
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Duff, T., Leykin, A. & Rodriguez, J.I. u-generation: solving systems of polynomials equation-by-equation. Numer Algor 95, 813–838 (2024). https://doi.org/10.1007/s11075-023-01590-1
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DOI: https://doi.org/10.1007/s11075-023-01590-1