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Combinatorial modifications of Reeb graphs and the realization problem. (English) Zbl 1465.57099

Let \(M\) be a closed manifold, \(\dim M\ge2\), and \(G\) be a finite digraph with a so-called good orientation. The author considers the following realization problem: Is \(G\) homeomorphic to the Reeb graph \(R_f\) of some Morse function \(f\) on \(M\)? He proves that this is true if and only if \[b_1(G)\le\mathcal{R}(M),\] where \(b_1(G)\) is the cycle rank of the graph and \(\mathcal{R}(M)\) is the maximum cycle rank among all Reeb graphs of smooth functions on \(M\) with finite number of critical points. Moreover, any integer \(r\in[0,\mathcal{R}(M)]\) can be realized as the cycle rank of the Reeb graph of a Morse function on \(M\); in particular, the above inequality is exact. In addition, \(\mathcal{R}(M)=corank(\pi_1(M))\), the corank of the fundamental group of the manifold.
For surfaces, \(\dim M=2\), the author has proved a similar result even up to isomorphism in his previous work [Ł. P. Michalak, Topol. Methods Nonlinear Anal. 52, No. 2, 749–762 (2018; Zbl 1425.58022)].

MSC:

57M15 Relations of low-dimensional topology with graph theory
05C76 Graph operations (line graphs, products, etc.)
05C38 Paths and cycles
68U10 Computing methodologies for image processing
57R70 Critical points and critical submanifolds in differential topology

References:

[1] Biasotti, S.; Giorgi, D.; Spagnuolo, M.; Falcidieno, B., Reeb graphs for shape analysis and applications, Theor. Comput. Sci., 392, 1-3, 5-22 (2008) · Zbl 1134.68064 · doi:10.1016/j.tcs.2007.10.018
[2] Cole-McLaughlin, K.; Edelsbrunner, H.; Harer, J.; Natarajan, V.; Pascucci, V., Loops in Reeb graphs of \(2\)-manifolds, Discrete Comput. Geom., 32, 2, 231-244 (2004) · Zbl 1071.57017 · doi:10.1007/s00454-004-1122-6
[3] Cornea, O., The genus and the fundamental group of high-dimensional manifolds, Stud. Cerc. Mat., 41, 3, 169-178 (1989) · Zbl 0694.57015
[4] Di Fabio, B.; Landi, C., The edit distance for Reeb graphs of surfaces, Discrete Comput. Geom., 55, 2, 423-461 (2016) · Zbl 1332.05038 · doi:10.1007/s00454-016-9758-6
[5] Gelbukh, I., The co-rank of the fundamental group: the direct product, the first Betti number, and the topology of foliations, Math. Slovaca, 67, 3, 645-656 (2017) · Zbl 1424.14003 · doi:10.1515/ms-2016-0298
[6] Gelbukh, I., Loops in Reeb graphs of \(n\)-manifolds, Discrete Comput. Geom., 59, 4, 843-863 (2018) · Zbl 1391.05144 · doi:10.1007/s00454-017-9957-9
[7] Gelbukh, I., Approximation of metric spaces by Reeb graphs: cycle rank of a Reeb graph, the co-rank of the fundamental group, and large components of level sets on Riemannian manifolds, Filomat, 33, 7, 2031-2049 (2019) · Zbl 1513.58005 · doi:10.2298/FIL1907031G
[8] Jaco, W., Geometric realizations for free quotients, J. Aust. Math. Soc., 14, 4, 411-418 (1972) · Zbl 0259.57004 · doi:10.1017/S1446788700011034
[9] Kaluba, M.; Marzantowicz, W.; Silva, N., On representation of the Reeb graph as a sub-complex of manifold, Topol. Methods Nonlinear Anal., 45, 1, 287-307 (2015) · Zbl 1364.00046 · doi:10.12775/TMNA.2015.015
[10] Kudryavtseva, EA, Reduction of Morse functions on surfaces to canonical form by smooth deformation, Regul. Chaotic Dyn., 4, 3, 53-60 (1999) · Zbl 1002.37026 · doi:10.1070/rd1999v004n03ABEH000116
[11] Martínez-Alfaro, J., Meza-Sarmiento, I.S., Oliveira, R.: Topological classification of simple Morse Bott functions on surfaces. In: Real and Complex Singularities (São Carlos 2014). Contemp. Math., vol. 675, pp. 165-179. Amer. Math. Soc., Providence (2016) · Zbl 1362.37078
[12] Masumoto, Y.; Saeki, O., A smooth function on a manifold with given Reeb graph, Kyushu J. Math., 65, 1, 75-84 (2011) · Zbl 1277.58022 · doi:10.2206/kyushujm.65.75
[13] Michalak, ŁP, Realization of a graph as the Reeb graph of a Morse function on a manifold, Topol. Methods Nonlinear Anal., 52, 2, 749-762 (2018) · Zbl 1425.58022
[14] Milnor, J., Lectures on the \(h\)-Cobordism Theorem (1965), Princeton: Princeton University Press, Princeton · Zbl 0161.20302 · doi:10.1515/9781400878055
[15] Reeb, G., Sur les points singuliers d’une forme de Pfaff complètement intégrable ou d’une fonction numérique, C. R. Acad. Sci. Paris, 222, 847-849 (1946) · Zbl 0063.06453
[16] Sharko, VV, About Kronrod-Reeb graph of a function on a manifold, Methods Funct. Anal. Topol., 12, 4, 389-396 (2006) · Zbl 1114.57034
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