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Triangulations with few vertices of manifolds with non-free fundamental group

Published online by Cambridge University Press:  15 January 2019

Petar Pavešić*
Affiliation:
Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenija ([email protected])

Abstract

We study lower bounds for the number of vertices in a PL-triangulation of a given manifold M. While most of the previous estimates are based on the dimension and the connectivity of M, we show that further information can be extracted by studying the structure of the fundamental group of M and applying techniques from the Lusternik-Schnirelmann category theory. In particular, we prove that every PL-triangulation of a d-dimensional manifold (d ⩾ 3) whose fundamental group is not free has at least 3d + 1 vertices. As a corollary, every d-dimensional homology sphere that admits a combinatorial triangulation with less than 3d vertices is PL-homeomorphic to Sd. Another important consequence is that every triangulation with small links of M is combinatorial.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 2019 

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References

1Bagchi, B. and Datta, B.. Combinatorial triangulations of homology spheres. Discrete Math. 305 (2005), 117.Google Scholar
2Borghini, E. and Minian, E. G.. The covering type of closed surfaces and minimal triangulations, arXiv:1712.02833 (2017), 6.Google Scholar
3Brehm, U. and Kühnel, W.. Combinatorial manifolds with few vertices. Topol. 26 (1987), 465473.Google Scholar
4Bryant, J. L.. Piecewise linear topology. In Handbook of geometric topology (ed.Daverman, R. J.. et al. ), pp. 219259 (Amsterdam: Elsevier, 2002).Google Scholar
5Cornea, O., Lupton, G., Oprea, J. and Tanre, D.. Lusternik-Schnirelmann category. Mathematical surveys and monographs, vol. 103 (Providence, RI: American Mathematical Society, 2003).Google Scholar
6Dranishnikov, A., Katz, M. and Rudyak, Y.. Small values of the Lusternik–Schnirelmann category for manifolds. Geom. Topol. 12 (2008), 17111727.Google Scholar
7Eels, J. and Kuiper, N.. Manifolds which are like projective planes. Publications mathématiques de l'I.H.É.S. 14 (1962), 546.Google Scholar
8Govc, D., Marzantowicz, W. and Pavešić, P.. Estimates of covering type and the number of vertices of minimal triangulations, arXiv:1710.03333 (2017), 19.Google Scholar
9Hatcher, A.. Algebraic topology (Cambridge: Cambridge University Press, 2002).Google Scholar
10 Joswig, M., Lutz, F. H. and Tsuruga, M.. Heuristics for sphere recognition, In Mathematical software – ICMS 2014, (eds. Hong, H. and Yap, C.) Lecture Notes in Computer Science, vol 8592 (Berlin, Heidelberg: Springer, 2014).Google Scholar
11Karoubi, M. and Weibel, C.. On the covering type of a space. Enseign Math. 62 (2016), 457474.Google Scholar
12 Klee, S. and Novik, I.. Face enumeration on simplicial complexes, In Recent trends in combinatorics, (eds. Beveridge, A. et al. ) The IMA volumes in Mathematics and its applications, vol. 159,pp. 653685 (Cham: Springer, 2016).Google Scholar
13Kühnel, W.. Higherdimensional analogues of Császár's torus. Result. Math. 9 (1986), 95106.Google Scholar
14Lutz, F. H.. Triangulated manifolds with few vertices: combinatorial manifolds, arXiv:math.CO/0506372v1 (2005), 37.Google Scholar
15Spanier, E. H.. Algebraic topology (New York: Springer-Verlag, 1966).Google Scholar
16Wall, C. T. C.. Classification of (n − 1)-connected 2n-manifolds. Ann. of Math. 75 (1962), 163189.Google Scholar