An Adjacency Criterion for Coxeter Matroids
Alexandre Borovik
and Andrew Vince
DOI: 10.1023/A:1018600303418
Abstract
A Coxeter matroid is a generalization of matroid, ordinary matroid being the case corresponding to the family of Coxeter groups A n , which are isomorphic to the symmetric groups. A basic result in the subject is a geometric characterization of Coxeter matroid in terms of the matroid polytope, a result first stated by Gelfand and Serganova. This paper concerns properties of the matroid polytope. In particular, a criterion is given for adjacency of vertices in the matroid polytope.
Pages: 271–280
Keywords: matroid; Coxeter matroid; Coxeter group; matroid polytope
Full Text: PDF
References
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2. A.V. Borovik and I.M. Gelfand, “Matroids on chamber systems,” Publ. LaCIM 14 (1993), 25-62.
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4. A.V. Borovik, I.M. Gelfand, A. Vince, and N. White, “The lattice of flats of a matroid and its underlying flag matroid polytope,” Annals of Combinatorics 1 (1997), 17-26.
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7. A.V. Borovik, I.M. Gelfand, and N. White, “Exchange properties of Coxeter matroids and oriented matroids,” Discrete Math. 179 (1998), 59-72.
8. A.V. Borovik, I.M. Gelfand, and N. White, “Symplectic matroids,” J. Alg. Comb., to appear.
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2. A.V. Borovik and I.M. Gelfand, “Matroids on chamber systems,” Publ. LaCIM 14 (1993), 25-62.
3. A.V. Borovik and I.M. Gelfand, “WP-matroids and thin Schubert cells on Tits systems,” Advances Math. 103 (1994), 162-179.
4. A.V. Borovik, I.M. Gelfand, A. Vince, and N. White, “The lattice of flats of a matroid and its underlying flag matroid polytope,” Annals of Combinatorics 1 (1997), 17-26.
5. A.V. Borovik, I.M. Gelfand, and N. White, Coxeter Matroids, Birkhauser, Boston, in preparation.
6. A.V. Borovik, I.M. Gelfand, and N. White, “Boundaries of Coxeter matroids,” Advances Math. 120 (1996), 258-264.
7. A.V. Borovik, I.M. Gelfand, and N. White, “Exchange properties of Coxeter matroids and oriented matroids,” Discrete Math. 179 (1998), 59-72.
8. A.V. Borovik, I.M. Gelfand, and N. White, “Symplectic matroids,” J. Alg. Comb., to appear.
9. A.V. Borovik, I.M. Gelfand, and N. White, “Coxeter matroid polytopes,” Annals of Combinatorics 1 (1997), 123-134.
10. A.V. Borovik and K.S. Roberts, “Coxeter groups and matroids,” in Groups of Lie Type and Geometries, W.M. Kantor and L.Di Martino (Eds.), Cambridge University Press, Cambridge, 1995, pp. 13-34.
11. A. Bouchet, “Greedy algorithm and symmetric matroids,” Math. Programming 38 (1987), 147-159.
12. I.M. Gelfand, M. Goresky, R.D. MacPherson, and V.V. Serganova, “Combinatorial geometries, convex polyhedra, and Schubert cells,” Advances Math. 63 (1987), 301-316.
13. I.M. Gelfand and V.V. Serganova, “On a general definition of a matroid and a greedoid,” Soviet Math. Dokl. 35 (1987), 6-10.
14. I.M. Gelfand and V.V. Serganova, “Combinatorial geometries and torus strata on homogeneous compact manifolds,” Russian Math. Surveys 42 (1987), 133-168; see also I.M. Gelfand, Collected Papers, Springer- Verlag, New York, 1989, Vol. 3, pp. 926-958.
15. H. Hiller, Geometry of Coxeter Groups, Pitman, Boston, 1982.
16. J.E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge University Press, Cambridge, 1976.
17. M. Ronan, Lectures on Buildings, Academic Press, Boston, 1989.
18. R. Scharlau, “Buildings,” preprint 93-016, Universit\ddot at Bielefeld (SFB 343 Diskrete Structuren in der Mathematik), 1993.
19. V.V. Serganova, A. Vince, and A. Zelevinsky, “Geometric characterization of Coxeter matroids,” Annals of Combinatorics 1 (1997), 173-181.
20. J. Tits, “A local approach to buildings,” The Geometric Vein (Coxeter Festschrift), Springer-Verlag, New York, 1981, pp. 317-322.
21. A. Vince, “The greedy algorithm and Coxeter matroids,” J. Alg. Comb., to appear.
22. W. Wenzel, Geometric Algebra of -Matroids and Related Combinatorial Geometries, Habilitationschrift, Bielefeld, 1991.
23. A.V. Zelevinsky and V.V. Serganova, “Combinatorial optimisation on Weyl groups, greedy algorithms and generalised matroids,” preprint, Acad. Sci. USSR, Scientific Council on the Complex Problem “Cybernetics”, Moscow, 1989, 24 pp. (in Russian).