A Congruence Modulo Four for Real Schubert Calculus with Isotropic Flags
Canadian mathematical bulletin, Tome 60 (2017) no. 2, pp. 309-318

Voir la notice de l'article provenant de la source Cambridge University Press

We previously obtained a congruence modulo four for the number of real solutions to many Schubert problems on a square Grassmannian given by osculating flags. Here we consider Schubert problems given by more general isotropic flags, and prove this congruence modulo four for the largest class of Schubert problems that could be expected to exhibit this congruence.
DOI : 10.4153/CMB-2016-087-2
Mots-clés : 14N15, 14P99, Lagrangian Grassmannian, Wronski map, Shapiro Conjecture
Hein, Nickolas; Sottile, Frank; Zelenko, Igor. A Congruence Modulo Four for Real Schubert Calculus with Isotropic Flags. Canadian mathematical bulletin, Tome 60 (2017) no. 2, pp. 309-318. doi: 10.4153/CMB-2016-087-2
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[1] [1] Anderson, B. and Helmke, U., Counting critical formations on a line. SIAM J. Control Optim. 52(2014), no. 1, 219–242. Google Scholar | DOI

[2] [2] Eisenbud, D. and Harris, J., Divisors on general curves and cuspidal rational curves. Invent. Math. 74(1983), 371–418. Google Scholar | DOI

[3] [3] Eremenko, A. and Gabrielov, A., Degrees of real Wronski maps. Discrete Comput. Geom. 28(2002), no. 3, 331–347. Google Scholar | DOI

[4] [4] Eremenko, A. and Gabrielov, A., Rational functions with real critical points and the B. and M. Shapiro conjecture in real enumerative geometry. Ann. of Math. (2) 155(2002), no. 1,105-129. Google Scholar | DOI

[5] [5] Fehér, L. M. and Â. Matszangosz, K., Real solutions of a problem in enumerative geometry. Period. Math. Hungar. 73(2016), no. 2, 137–156. Google Scholar | DOI

[6] [6] Finashin, S. and Kharlamov, V., Abundance of real lines on real projective hypersurfaces. Int. Math. Res. Notices (2012). Google Scholar

[7] [7] Hein, N., Hillar, C. J., and Sottile, F., Lower bounds in real Schubert calculus. Sâo Paulo J. Math. Sci. 7(2013), no. 1, 33–58. Google Scholar | DOI

[8] [8] Hein, N. and Sottile, F., Beyond the Shapiro Conjecture and Eremenko-Gabrielov lower bounds, 2013, http://www.math.tamu.edu/∼Osecant/lowerBounds/lowerBounds.php. Google Scholar

[9] [9] Hein, N., Sottile, F., and Zelenko, I., A congruence modulo four in real Schubert calculus. 2014, J. Reine Angew. Math., to appear. Google Scholar

[10] [10] Itenberg, I. V., Kharlamov, V. M., and Shustin, E. I., Welschinger invariant and enumeration of real rational curves. Int. Math. Res. Not. (2003), no. 49, 2639–2653. Google Scholar

[11] [11] Itenberg, I. V., Kharlamov, V. M., Logarithmic equivalence of the Welschinger and the Gromov-Witten invariants. Uspekhi Mat. Nauk 59(2004), no. 6(360), 85–110. Google Scholar | DOI

[12] [12] Kleiman, S. L., The transversality of a general translate. Compositio Math. 28(1974), 287–297. Google Scholar

[13] [13] Martin del Campo, A. and Sottile, F., Experimentation in the Schubert calculus. In: Schubert Calculus (Osaka 2012), Advanced Studies in Pure Mathematics, 71, Mathematical Society of Japan, 2016, pp. 295–335. Google Scholar

[14] [14] Mukhin, E. and Tarasov, V., Lower bounds for numbers of real solutions in problems of Schubert calculus. 2014, arxiv:1404.71 94. Google Scholar

[15] [15] Mukhin, E., Tarasov, V., and Varchenko, A., The B. and Shapiro M. conjecture in real algebraic geometry and the Bethe ansatz. Ann. of Math. (2) 170(2009), no. 2, 863–881. Google Scholar | DOI

[16] [16] Mukhin, E., Schubert calculus and representations of the general linear group. J. Amer. Math. Soc. 22(2009), no. 4, 909–940. Google Scholar | DOI

[17] [17] Okonek, C. and Teleman, A., Intrinsic signs and lower bounds in real algebraic geometry J. Reine Angew. Math. 688(2014), 219–241. Google Scholar

[18] [18] Okonek, C. and Teleman, A., A wall-crossing formula for degrees of real central projections. Int. J. Math. 25(2014), 1450038, 34 pp. Google Scholar | DOI

[19] [19] Purbhoo, K., Reality and transversality for Schubert calculus in OG(«, 2” + 1). Math. Res. Lett. 17(2010), no. 6, 1041–1046. Google Scholar | DOI

[20] [20] Soprunova, E. and Sottile, F., Lower bounds for real solutions to sparse polynomial systems. Adv. Math. 204(2006), no. 1, 116–151. Google Scholar | DOI

[21] [21] Sottile, F., The special Schubert calculus is real. Electronic Research Announcements of the AMS 5(1999), 35–39. Google Scholar | DOI

[22] [22] Sottile, F., Some real and unreal enumerative geometry for flag manifolds. Mich. Math. J. 48(2000), 573–592. Google Scholar | DOI

[23] [23] Sottile, F., General isotropic flags are general (for Grassmannian Schubert calculus). J. Algebraic Geom. 19(2010), no. 2,367-370. Google Scholar | DOI

[24] [24] Welschinger, J.-Y., Invariants of real rational symplectic 4-manifolds and lower bounds in real enumerative geometry. C. R. Math. Acad. Sci. Paris 336(2003), no. 4, 341–344. Google Scholar | DOI

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