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The extreme rays of the \(6\times 6\) copositive cone

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Abstract

We provide a complete classification of the extreme rays of the \(6 \times 6\) copositive cone \(\mathcal {COP}^{6}\). We proceed via a coarse intermediate classification of the possible minimal zero support set of an exceptional extremal matrix \(A \in \mathcal {COP}^{6}\). To each such minimal zero support set we construct a stratified semi-algebraic manifold in the space of real symmetric \(6 \times 6\) matrices \({\mathcal {S}}^{6}\), parameterized in a semi-trigonometric way, which consists of all exceptional extremal matrices \(A \in \mathcal {COP}^{6}\) having this minimal zero support set. Each semi-algebraic stratum is characterized by the supports of the minimal zeros u as well as the supports of the corresponding matrix-vector products Au. The analysis uses recently and newly developed methods that are applicable to copositive matrices of arbitrary order.

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Notes

  1. P.J.C. Dickinson, R. de Zeeuw. Generating irreducible copositive matrices using the stable set problem. In press in Discrete Appl. Math., 2020.

References

  1. Baumert, L.D.: Extreme copositive quadratic forms. Pac. J. Math. 19(2), 197–204 (1966)

    Article  MathSciNet  MATH  Google Scholar 

  2. Bomze, I.M.: Copositive optimization—recent developments and applications. Eur. J. Oper. Res. 216(3), 509–520 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  3. Bomze, I.M., Schachinger, W., Uchida, G.: Think co(mpletely )positive! Matrix properties, examples and a clustered bibliography on copositive optimization. J. Global Optim. 52, 423–445 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  4. Bomze, I.M., Schachinger, W., Ullrich, R.: From seven to eleven: completely positive matrices with high cp-rank. Linear Algebra Appl. 459, 208–221 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  5. Bomze, I.M., Schachinger, W., Ullrich, R.: New lower bounds and asymptotics for the cp-rank. SIAM. J. Matrix Anal. Appl. 36(1), 20–37 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  6. Diananda, P.H.: On nonnegative forms in real variables some or all of which are nonnegative. Proc. Cambr. Philos. Soc. 58, 17–25 (1962)

    Article  MathSciNet  MATH  Google Scholar 

  7. Dickinson, P.J.: A new certificate for copositivity. Linear Algebra Appl. 569, 15–37 (2019)

    Article  MathSciNet  MATH  Google Scholar 

  8. Dickinson, P.J., Dür, M., Gijben, L., Hildebrand, R.: Irreducible elements of the copositive cone. Linear Algebra Appl. 439, 1605–1626 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  9. Dickinson, P.J., Dür, M., Gijben, L., Hildebrand, R.: Scaling relationship between the copositive cone and Parrilo’s first level approximation. Optim. Lett. 7, 1669–1679 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  10. Dickinson, P.J., Hildebrand, R.: Considering copositivity locally. J. Math. Anal. Appl. 437(2), 1184–1195 (2016)

    Article  MathSciNet  MATH  Google Scholar 

  11. Dickinson, P.J.C.: Geometry of the copositive and completely positive cones. J. Math. Anal. Appl. 380(1), 377–395 (2011)

    Article  MathSciNet  MATH  Google Scholar 

  12. Dür, M.: Copositive programming—a survey. In: Diehl, M., Glineur, F., Jarlebring, E., Michiels, W. (eds.) Recent Advances in Optimization and its Applications in Engineering, pp. 3–20. Springer, Berlin (2010)

    Chapter  Google Scholar 

  13. Hall, M.J., Newman, M.: Copositive and completely positive quadratic forms. Proc. Cambr. Philos. Soc. 59(2), 329–339 (1963)

    Article  MathSciNet  MATH  Google Scholar 

  14. Haynsworth, E., Hoffman, A.J.: Two remarks on copositive matrices. Linear Algebra Appl. 2, 387–392 (1969)

    Article  MathSciNet  MATH  Google Scholar 

  15. Hildebrand, R.: The extreme rays of the \(5\times 5\) copositive cone. Linear Algebra Appl. 437(7), 1538–1547 (2012)

    MathSciNet  MATH  Google Scholar 

  16. Hildebrand, R.: Minimal zeros of copositive matrices. Linear Algebra Appl. 459, 154–174 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  17. Hildebrand, R.: Copositive matrices with circulant zero support set. Linear Algebra Appl. 514, 1–46 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  18. Hildebrand, R.: Extremal copositive matrices with minimal zero supports of cardinality two. Linear Multilinear Algebra 66(11), 2151–2155 (2018)

    Article  MathSciNet  MATH  Google Scholar 

  19. Hiriart-Urruty, J.B., Seeger, A.: A variational approach to copositive matrices. SIAM Rev. 52(4), 593–629 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  20. Hoffman, A.J., Pereira, F.: On copositive matrices with \(-\)1, 0, 1 entries. J. Combin. Theory 14, 302–309 (1973)

    MathSciNet  MATH  Google Scholar 

  21. Murty, K.G., Kabadi, S.N.: Some NP-complete problems in quadratic and nonlinear programming. Math. Program. 39, 117–129 (1987)

    Article  MathSciNet  MATH  Google Scholar 

  22. Shaked-Monderer, N.: On the DJL conjecture for order 6. Oper. Matrices 11(1), 71–88 (2017)

    Article  MathSciNet  MATH  Google Scholar 

  23. Shaked-Monderer, N., Berman, A., Bomze, I.M., Jarre, F., Schachinger, W.: New results on the cp-rank and related properties of co(mpletely) positive matrices. Linear Multilinear Algebra 63(2), 384–396 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  24. Shaked-Monderer, N., Bomze, I.M., Jarre, F., Schachinger, W.: On the cp-rank and minimal cp factorizations of a completely positive matrix. SIAM J. Matrix Anal. Appl. 34(2), 355–368 (2013)

    Article  MathSciNet  MATH  Google Scholar 

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Acknowledgements

The authors would like to thank the anonymous referees for a very thorough reading of the paper and for suggesting valuable improvements.

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Correspondence to Roland Hildebrand.

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Afonin, A., Hildebrand, R. & Dickinson, P.J.C. The extreme rays of the \(6\times 6\) copositive cone. J Glob Optim 79, 153–190 (2021). https://doi.org/10.1007/s10898-020-00930-y

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