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Counterexamples to the Neggers-Stanley conjecture

Author(s): Petter Brändén
Journal: Electron. Res. Announc. Amer. Math. Soc. 10 (2004), 155 - 158.
MSC (2000): Primary 06A07, 26C10
Posted: December 24, 2004
MathSciNet review: 2119757
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Abstract | References | Similar articles | Additional information

Abstract: The Neggers-Stanley conjecture asserts that the polynomial counting the linear extensions of a labeled finite partially ordered set by the number of descents has real zeros only. We provide counterexamples to this conjecture.


References:

1.
P. Brändén, Sign-graded posets, unimodality of $W$-polynomials and the Charney-Davis conjecture, Electr. J. Combin. 11(2), #9.

2.
F. Brenti, Unimodal, log-concave and Pólya frequency sequences in combinatorics, Mem. Amer. Math. Soc. 413, Amer. Math. Soc., Providence, 1989. MR 0963833 (90d:05014)

3.
L. H. Harper, Stirling behavior is asymptotically normal, Ann. Math. Statist. 38 (1967), 410-414. MR 0211432 (35:2312)

4.
J. Neggers, Representations of finite partially ordered sets, J. Comb. Inf. Syst. Sci. 3 (1978), 113-133. MR 0551484 (58:27668)

5.
Q. I. Rahman and G. Schmeisser, Analytic theory of polynomials, The Clarendon Press, Oxford University Press, Oxford, 2002. MR 1954841 (2004b:30015)

6.
V. Reiner and V. Welker, On the Charney-Davis and Neggers-Stanley conjectures, preprint; available at www.math.umn.edu/~reiner/.

7.
R. Simion, A multiindexed Sturm sequence of polynomials and unimodality of certain combinatorial sequences. J. Comb. Theory, Ser. A 36 (1984), 15-22. MR 0728500 (85e:05015)

8.
R. P. Stanley, Ordered structures and partitions, Mem. Amer. Math. Soc. 119, Amer. Math. Soc., Providence, 1972. MR 0332509 (48:10836)

9.
R. P. Stanley, Hilbert functions of graded algebras, Adv. Math. 28 (1978), 57-83. MR 0485835 (58:5637)

10.
R. P. Stanley, Combinatorics and commutative algebra, Birkhäuser Boston Inc., Boston, MA, 2nd edition, 1996. MR 1453579 (98h:05001)

11.
D. Wagner, Enumeration of functions from posets to chains, Eur. J. Comb. 13 (1992), 313-324. MR 1179527 (94c:05008)


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Additional Information:

Petter Brändén
Affiliation: Department of Mathematics, Chalmers University of Technology and Göteborg University, S-412~96 Göteborg, Sweden
Email: branden@math.chalmers.se

DOI: 10.1090/S1079-6762-04-00140-4
PII: S 1079-6762(04)00140-4
Keywords: Neggers-Stanley conjecture, partially ordered set, linear extension, real roots
Received by editor(s): August 31, 2004
Posted: December 24, 2004
Communicated by: Sergey Fomin
Copyright of article: Copyright 2004, American Mathematical Society
The copyright for this article reverts to public domain after 28 years from publication.




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