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Computing the Homology of Real Projective Sets

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Abstract

We describe and analyze a numerical algorithm for computing the homology (Betti numbers and torsion coefficients) of real projective varieties. Here numerical means that the algorithm is numerically stable (in a sense to be made precise). Its cost depends on the condition of the input as well as on its size and is singly exponential in the number of variables (the dimension of the ambient space) and polynomial in the condition and the degrees of the defining polynomials. In addition, we show that outside of an exceptional set of measure exponentially small in the size of the data, the algorithm takes exponential time.

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References

  1. E.L. Allgower and K. Georg. Numerical Continuation Methods. Springer-Verlag, 1990.

  2. D. Amelunxen and M. Lotz. Average-case complexity without the black swans. To appear at J. Compl. Available at arXiv:1512.09290, 2016.

  3. S. Basu. Computing the top Betti numbers of semialgebraic sets defined by quadratic inequalities in polynomial time. Found. Comput. Math., 8(1):45–80, 2008.

    Article  MathSciNet  MATH  Google Scholar 

  4. S. Basu, R. Pollack, and M.-F. Roy. Computing the first Betti number of a semi-algebraic set. Found. Comput. Math., 8(1):97–136, 2008.

    Article  MathSciNet  MATH  Google Scholar 

  5. A. Björner. Topological methods. In R. Graham, M. Grotschel, and L. Lovasz, editors, Handbook of Combinatorics, pages 1819–1872. North-Holland, Amsterdam, 1995.

    Google Scholar 

  6. L. Blum, F. Cucker, M. Shub, and S. Smale. Complexity and Real Computation. Springer-Verlag, 1998.

  7. L. Blum, M. Shub, and S. Smale. On a theory of computation and complexity over the real numbers: NP-completeness, recursive functions and universal machines. Bulletin of the Amer. Math. Soc., 21:1–46, 1989.

    Article  MathSciNet  MATH  Google Scholar 

  8. P. Bürgisser and F. Cucker. Counting complexity classes for numeric computations II: Algebraic and semialgebraic sets. J. Compl., 22:147–191, 2006.

    Article  MathSciNet  MATH  Google Scholar 

  9. P. Bürgisser and F. Cucker. Exotic quantifiers, complexity classes, and complete problems. Found. Comput. Math., 9:135–170, 2009.

    Article  MathSciNet  MATH  Google Scholar 

  10. P. Bürgisser and F. Cucker. Condition, volume 349 of Grundlehren der mathematischen Wissenschaften. Springer-Verlag, Berlin, 2013.

    MATH  Google Scholar 

  11. D. Cheung and F. Cucker. Solving linear programs with finite precision: II. Algorithms. J. Compl., 22:305–335, 2006.

    MathSciNet  MATH  Google Scholar 

  12. G.E. Collins. Quantifier elimination for real closed fields by cylindrical algebraic deccomposition, volume 33 of Lect. Notes in Comp. Sci., pages 134–183. Springer-Verlag, 1975.

  13. F. Cucker. Approximate zeros and condition numbers. J. Compl., 15:214–226, 1999.

    Article  MathSciNet  MATH  Google Scholar 

  14. F. Cucker, H. Diao, and Y. Wei. Smoothed analysis of some condition numbers. Numer. Lin. Alg. Appl., 13:71–84, 2006.

    Article  MathSciNet  MATH  Google Scholar 

  15. F. Cucker, T. Krick, G. Malajovich, and M. Wschebor. A numerical algorithm for zero counting. I: Complexity and accuracy. J. Compl., 24:582–605, 2008.

    Article  MathSciNet  MATH  Google Scholar 

  16. F. Cucker, T. Krick, G. Malajovich, and M. Wschebor. A numerical algorithm for zero counting. II: Distance to ill-posedness and smoothed analysis. J. Fixed Point Theory Appl., 6:285–294, 2009.

    Article  MathSciNet  MATH  Google Scholar 

  17. F. Cucker, T. Krick, G. Malajovich, and M. Wschebor. A numerical algorithm for zero counting. III: Randomization and condition. Adv. Applied Math., 48:215–248, 2012.

    Article  MathSciNet  MATH  Google Scholar 

  18. F. Cucker and J. Peña. A primal-dual algorithm for solving polyhedral conic systems with a finite-precision machine. SIAM J. Optim., 12:522–554, 2002.

    Article  MathSciNet  MATH  Google Scholar 

  19. F. Cucker and S. Smale. Complexity estimates depending on condition and round-off error. Journal of the ACM, 46:113–184, 1999.

    Article  MathSciNet  MATH  Google Scholar 

  20. Carlos D’Andrea, Teresa Krick, and Martín Sombra. Heights of varieties in multiprojective spaces and arithmetic Nullstellensätze. Ann. Sci. Éc. Norm. Supér. (4), 46(4):549–627 (2013), 2013.

  21. J. Demmel. The probability that a numerical analysis problem is difficult. Math. Comp., 50:449–480, 1988.

    Article  MathSciNet  MATH  Google Scholar 

  22. H. Edelsbrunner and J.L. Harer. Computational topology. American Mathematical Society, Providence, RI, 2010. An introduction.

  23. E. Kostlan. Complexity theory of numerical linear algebra. J. of Computational and Applied Mathematics, 22:219–230, 1988.

    Article  MathSciNet  MATH  Google Scholar 

  24. M. Lotz. On the volume of tubular neighborhoods of real algebraic varieties. Proc. Amer. Math. Soc., 143(5):1875–1889, 2015.

    Article  MathSciNet  MATH  Google Scholar 

  25. P. Niyogi, S. Smale, and S. Weinberger. Finding the homology of submanifolds with high confidence from random samples. Discrete Comput. Geom., 39:419–441, 2008.

    Article  MathSciNet  MATH  Google Scholar 

  26. V. Noferini and A. Townsend. Numerical instability of resultant methods for multidimensional rootfinding. To appear at SIAM J. Num. Analysis. Available at arXiv:1507.00272.

  27. J. Renegar. On the computational complexity and geometry of the first-order theory of the reals. Part I. Journal of Symbolic Computation, 13:255–299, 1992.

    Article  MathSciNet  MATH  Google Scholar 

  28. J. Renegar. Some perturbation theory for linear programming. Math. Program., 65:73–91, 1994.

    Article  MathSciNet  MATH  Google Scholar 

  29. J. Renegar. Incorporating condition measures into the complexity theory of linear programming. SIAM J. Optim., 5:506–524, 1995.

    Article  MathSciNet  MATH  Google Scholar 

  30. J. Renegar. Linear programming, complexity theory and elementary functional analysis. Math. Program., 70:279–351, 1995.

    MathSciNet  MATH  Google Scholar 

  31. P. Scheiblechner. On the complexity of deciding connectedness and computing Betti numbers of a complex algebraic variety. J. Complexity, 23(3):359–379, 2007.

    Article  MathSciNet  MATH  Google Scholar 

  32. P. Scheiblechner. Castelnuovo-Mumford regularity and computing the de Rham cohomology of smooth projective varieties. Found. Comput. Math., 12(5):541–571, 2012.

    Article  MathSciNet  MATH  Google Scholar 

  33. M. Shub and S. Smale. Complexity of Bézout’s Theorem I: geometric aspects. Journal of the Amer. Math. Soc., 6:459–501, 1993.

    MathSciNet  MATH  Google Scholar 

  34. M. Shub and S. Smale. Complexity of Bézout’s Theorem II: volumes and probabilities. In F. Eyssette and A. Galligo, editors, Computational Algebraic Geometry, volume 109 of Progress in Mathematics, pages 267–285. Birkhäuser, 1993.

  35. M. Shub and S. Smale. Complexity of Bézout’s Theorem III: condition number and packing. Journal of Complexity, 9:4–14, 1993.

    Article  MathSciNet  MATH  Google Scholar 

  36. M. Shub and S. Smale. Complexity of Bézout’s Theorem V: polynomial time. Theoret. Comp. Sci., 133:141–164, 1994.

    Article  MATH  Google Scholar 

  37. M. Shub and S. Smale. Complexity of Bézout’s Theorem IV: probability of success; extensions. SIAM J. of Numer. Anal., 33:128–148, 1996.

    Article  MATH  Google Scholar 

  38. S. Smale. Newton’s method estimates from data at one point. In R. Ewing, K. Gross, and C. Martin, editors, The Merging of Disciplines: New Directions in Pure, Applied, and Computational Mathematics. Springer-Verlag, 1986.

  39. A. Storjohann. Nearly optimal algorithms for computing Smith normal forms of integer matrices. In Proceedings of the International Symposium on Symbolic and Algebraic Computation (ISSAC’96), pages 267–274. ACM Press, 1996.

  40. H.R. Wüthrich. Ein Entscheidungsverfahren für die Theorie der reell-abgeschlossenen Körper. In E. Specker and V. Strassen, editors, Komplexität von Entscheidungsproblemen, volume 43 of Lect. Notes in Comp. Sci., pages 138–162. Springer-Verlag, 1976.

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Acknowledgements

We are grateful to Peter Bürgisser who suggested the topic of this paper to us and to the Simons Institute for receiving us in the Fall of 2014, which was where and when the suggestion was made. We also owe an anonymous referee for his very precise and enlightening comments.

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Correspondence to Teresa Krick.

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Communicated by Shmuel Weinberger.

Felipe Cucker partially supported by a GRF Grant from the Research Grants Council of the Hong Kong SAR (Project Number CityU 11310716). Teresa Krick partially supported by Grants BID-PICT-2013-0294, UBACyT-2014-2017-20020130100143BA and PIP-CONICET 2014-2016-11220130100073CO.

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Cucker, F., Krick, T. & Shub, M. Computing the Homology of Real Projective Sets. Found Comput Math 18, 929–970 (2018). https://doi.org/10.1007/s10208-017-9358-8

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  • DOI: https://doi.org/10.1007/s10208-017-9358-8

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