Abstract
We present an explicit combinatorial description of a special class of facets of the secondary polytopes of hypersimplices. These facets correspond to polytopal subdivisions called multi-splits. We show that the maximal cells in a multi-split of a hypersimplex are matroid polytopes of nested matroids. Moreover, we derive a description of all multi-splits of a product of simplices. Additionally, we present a computational result to derive explicit lower bounds on the number of facets of secondary polytopes of hypersimplices.
Similar content being viewed by others
References
Babson, E.K., Billera, L.J.: The geometry of products of minors. Discrete Comput. Geom. 20(2), 231–249 (1998)
Bandelt, H.-J., Dress, A.W.M.: A canonical decomposition theory for metrics on a finite set. Adv. Math. 92(1), 47–105 (1992)
Bonin, J.E., de Mier, A.: The lattice of cyclic flats of a matroid. Ann. Comb. 12(2), 155–170 (2008)
Ceballos, C., Santos, F., Ziegler, G.M.: Many non-equivalent realizations of the associahedron. Combinatorica 35(5), 513–551 (2015)
De Loera, J.A., Rambau, J., Santos. F.: Triangulations: Structures for Algorithms and Applications. Algorithms and Computation in Mathematics, vol. 25. Springer, Berlin (2010)
Develin, M., Sturmfels, B.: Tropical convexity. Doc. Math. 9, 1–27 (electronic), Erratum ibid. 205–206 (2004)
Dress, A.W.M., Wenzel, W.: Valuated matroids. Adv. Math. 93(2), 214–250 (1992)
Edmonds, J.: Submodular functions, matroids, and certain polyhedra. In: Guy, R. et al. (eds.) Combinatorial Structures and Their Applications (Proc. Calgary Internat. Conf., Calgary, Alta., 1969), pp. 69–87. Gordon and Breach, New York (1970)
Feichtner, E.M., Sturmfels, B.: Matroid polytopes, nested sets and Bergman fans. Port. Math. (N.S.) 62(4), 437–468 (2005)
Fink, A., Rincón, F.: Stiefel tropical linear spaces. J. Comb. Theory, Ser. A 135, 291–331 (2015)
Fujishige, S.: A characterization of faces of the base polyhedron associated with a submodular system. J. Oper. Res. Soc. Jpn. 27(2), 112–129 (1984)
Gawrilow, E., Joswig, M.: Polymake: a framework for analyzing convex polytopes. In: Kalai, G., Ziegler, G.M. (eds.) Polytopes—Combinatorics and Computation (Oberwolfach, 1997), DMV Sem., vol. 29, pp. 43–73. Birkhäuser, Basel (2000)
Gelfand, I.M., Kapranov, M.M., Zelevinsky, A.V.: Discriminants, Resultants and Multidimensional Determinants. Modern Birkhäuser Classics. Birkhäuser Boston, Inc., Boston, MA (2008). Reprint of the 1994 edition
Hampe, S.: The intersection ring of matroids. J. Comb. Theory, Ser. B 122, 578–614 (2017)
Herrmann, S.: On the facets of the secondary polytope. J. Comb. Theory, Ser. A 118(2), 425–447 (2011)
Herrmann, S., Jensen, A., Joswig, M., Sturmfels, B.: How to draw tropical planes. Electron. J. Comb. 16(2), 6 (2009)
Herrmann, S., Joswig, M.: Splitting polytopes. Münster J. Math. 1, 109–141 (2008)
Herrmann, S., Joswig, M., Speyer, D.: Dressians, tropical Grassmannians and their rays. Forum Math. 26(6), 389–411 (2014)
Hirai, H.: A geometric study of the split decomposition. Discrete Comput. Geom. 36(2), 331–361 (2006)
Jordan, C., Joswig, M., Kastner, L.: Parallel enumeration of triangulations. Electron. J. Comb. 25(3), # P3.6 (2018). arXiv:1709.04746
Joswig, M., Schröter, B.: Matroids from hypersimplex splits. J. Comb. Theory, Ser. A 151, 254–284 (2017)
Koichi, S.: The Buneman index via polyhedral split decomposition. Adv. Appl. Math. 60, 1–24 (2014)
Matsumoto, Y., Moriyama, S., Imai, H., Bremner, D.: Matroid enumeration for incidence geometry. Discrete Comput. Geom. 47(1), 17–43 (2012)
Oxley, J.: Matroid Theory. Oxford Graduate Texts in Mathematics, vol. 21. Oxford University Press, Oxford (2011)
Rincón, F.: Local tropical linear spaces. Discrete Comput. Geom. 50(3), 700–713 (2013)
Schrijver, A.: Theory of Linear and Integer Programming. Wiley-Interscience Series in Discrete Mathematics. Wiley, Chichester (1986)
Schröter, B.: Matroidal Subdivisions, Dressians and Tropical Grassmannians. PhD thesis, Technische Universität Berlin (2018)
Speyer, D.E.: Tropical Geometry. ProQuest LLC, Ann Arbor, MI. Thesis (Ph.D.), University of California, Berkeley (2005)
Speyer, D., Sturmfels, B.: The tropical Grassmannian. Adv. Geom. 4(3), 389–411 (2004)
White, N. (ed.): Theory of Matroids. Encyclopedia of Mathematics and Its Applications, vol. 26. Cambridge University Press, Cambridge (1986)
Ziegler, G.M.: Lectures on Polytopes. Graduate Texts in Mathematics. Springer, New York (1995)
Acknowledgements
I am indebted to Michael Joswig and Georg Loho for various helpful suggestions and I thank Alex Fink and the three anonymous referees for their comments. My research is carried out in the framework of Matheon supported by Einstein Foundation Berlin (Project “MI6 - Geometry of Equilibria for Shortest Path”). Furthermore, I thank Institut Mittag-Leffler for the hospitality during my stay in early 2018.
Author information
Authors and Affiliations
Corresponding author
Additional information
Editor in Charge: János Pach
Rights and permissions
About this article
Cite this article
Schröter, B. Multi-splits and Tropical Linear Spaces from Nested Matroids. Discrete Comput Geom 61, 661–685 (2019). https://doi.org/10.1007/s00454-018-0021-1
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00454-018-0021-1