We consider a special class of nonsingular oriented foliations F on noncompact surfaces Σ whose spaces of leaves have a structure similar to the structure of rooted trees of finite diameter. Let H +(F) be the group of all homeomorphisms of Σ mapping the leaves onto leaves and preserving their orientations. In addition, let K be the group of homeomorphisms of the quotient space Σ/F induced by H +(F). By \( {H}_0^{+}(F) \) and K 0 we denote the corresponding subgroups formed by the homeomorphisms isotopic to identity mappings. Our main result establishes the isomorphism between the homeotopy groups \( {\pi}_0{H}^{+}(F)={H}^{+}(F)/{H}_0^{+}(F) \) and π 0 K = K/K 0 .
References
A. V. Bolsinov and A. T. Fomenko, Introduction to the Topology of Integrable Hamiltonian Systems [in Russian], Nauka, Moscow (1997).
A. A. Oshemkov, “Morse functions on two-dimensional surfaces. Encoding of singularities,” Tr. Mat. Inst. Ros. Akad. Nauk, 205, 131–140 (1994).
V. V. Sharko, “Smooth and topological equivalence of functions on surfaces,” Ukr. Mat. Zh., 55, No. 5, 687–700 (2003); English translation: Ukr. Math. J., 55, No. 5, 832–846 (2003).
V. V. Sharko, “Smooth functions on noncompact surfaces,” Pr. Inst. Mat., Nats. Akad. Nauk Ukr., Mat. Zastos., 3, No. 3, 443–473 (2006); Preprint arXiv:math/0709.2511.
A. O. Prishlyak, “Conjugacy of Morse functions on surfaces with values on a straight line and circle,” Ukr. Mat. Zh., 52, No. 10, 1421–1425 (2000); English translation: Ukr. Math. J., 52, No. 10, 1623–1627 (2000).
E. A. Polulyakh, “Kronrod–Reeb graphs of functions on noncompact two-dimensional surfaces. I,” Ukr. Mat. Zh., 67, No. 3, 375–396 (2015); English translation: Ukr. Math. J., 67, No. 3, 431–454 (2015).
O. O. Prishlyak, “Morse functions with finite number of singularities on a plane,” Meth. Funct. Anal. Topol., 8, No. 1, 75–78 (2002).
E. Polulyakh and I. Yurchuk, “On the pseudo-harmonic functions defined on a disk,” Pr. Inst. Mat., Nats. Akad. Nauk Ukr., Mat. Zastos., 80, 151 (2009).
V. V. Sharko and Yu. Yu. Soroka, “Topological equivalence to a projection,” Meth. Funct. Anal. Topol., 21, No. 1, 3–5 (2015).
W. Kaplan, “Regular curve-families filling the plane, I,” Duke Math. J., 7, 154–185 (1940).
W. Kaplan, “Regular curve-families filling the plane, II,” Duke Math. J., 8, 11–46 (1941).
H. Whitney, “Regular families of curves,” Ann. Math., 34, No. 2, 244–270 (1933).
W. M. Boothby, “The topology of regular curve families with multiple saddle points,” Amer. J. Math., 73, 405–438 (1951).
J. Jenkins and M. Marston, “Contour equivalent pseudoharmonic functions and pseudoconjugates,” Amer. J. Math., 74, 23–51 (1952).
S. Maksymenko and E. Polulyakh, “Foliations with non-compact leaves on surfaces,” Proc. Geom. Center., 8, No. 3-4, 17–30 (2015).
S. Maksymenko and E. Polulyakh, “Foliations with all non-closed leaves on non-compact surfaces,” Meth. Funct. Anal. Topol., 22, No. 3, 266–282 (2016); Preprint arXiv:1606.00045.
Yu. Yu. Soroka, “Homeotopy groups of rooted tree like non-singular foliations on the plane,” Meth. Funct. Anal. Topol., 22, No. 3, 283–294 (2016); Preprint arXiv:1607.04097.
D. B. A. Epstein, “Curves on 2-manifolds and isotopies,” Acta Math., 115, 83–107 (1966).
V. A. Rokhlin and D. B. Fuks, A First Course in Topology. Geometric Chapters [in Russian], Nauka, Moscow (1977).
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Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 69, No. 7, pp. 1000–1008, July, 2017.
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Soroka, Y.Y. Homeotopy Groups for Nonsingular Foliations of the Plane. Ukr Math J 69, 1164–1174 (2017). https://doi.org/10.1007/s11253-017-1423-6
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DOI: https://doi.org/10.1007/s11253-017-1423-6