×

Strictly ascending HNN extensions in soluble groups. (English) Zbl 1305.20041

Summary: We show that there exist finitely generated soluble groups which are not LERF but which do not contain strictly ascending HNN extensions of a cyclic group. This solves Problem 16.2 in the Kourovka notebook (2006; Zbl 1084.20001). We further show that there is a finitely presented soluble group which is not LERF but which does not contain a strictly ascending HNN extension of a polycyclic group.

MSC:

20F16 Solvable groups, supersolvable groups
20E06 Free products of groups, free products with amalgamation, Higman-Neumann-Neumann extensions, and generalizations
20E26 Residual properties and generalizations; residually finite groups
20E07 Subgroup theorems; subgroup growth
20F05 Generators, relations, and presentations of groups

Citations:

Zbl 1084.20001

References:

[1] Alperin, R.C.: Solvable groups of exponential growth and HNN-extensions. In: Groups–Korea ’96, Pusan. de Gruyter, Berlin, pp. 1–5 (2000) · Zbl 0953.20026
[2] Alperin, R.C.: Metabelian Wreath Products are LERF. http://arxiv.org/abs/math/0609611 (2006)
[3] Baumslag G., Bieri R.: Constructable solvable groups. Math. Z. 151, 249–257 (1976) · Zbl 0356.20028 · doi:10.1007/BF01214937
[4] Blass A., Neumann P.M.: An application of universal algebra in group theory. Mich. Math. J. 21, 167–169 (1974) · Zbl 0292.20033 · doi:10.1307/mmj/1029001263
[5] Burns R.G., Karrass A., Solitar D.: A note on groups with separable finitely generated subgroups. Bull. Aust. Math. Soc. 36, 153–160 (1987) · Zbl 0613.20018 · doi:10.1017/S0004972700026393
[6] Button J.O.: Mapping tori with first Betti number at least two. J. Math. Soc. Jpn. 59, 351–370 (2007) · Zbl 1124.57001 · doi:10.2969/jmsj/05920351
[7] Button, J.O.: Largeness of LERF and 1-relator groups. Groups Geom. Dyn. 4, 709–738 (2010) · Zbl 1248.20033
[8] de Cornulier Y.: Finitely presented wreath products and double coset decompositions. Geom. Dedicata 122, 89–108 (2006) · Zbl 1137.20019 · doi:10.1007/s10711-006-9061-4
[9] Gruenberg K.W.: Residual properties of infinite soluble groups. Proc. Lond. Math. Soc. 7, 29–62 (1957) · Zbl 0077.02901 · doi:10.1112/plms/s3-7.1.29
[10] Jeanes, S.C., Wilson, J.S.: On finitely generated groups with many profinite-closed subgroups. Arch. Math. (Basel) 31, 120–122 (1978/79) · Zbl 0377.20029
[11] Mazurov, V.D., Khukhro, E.I. (eds.): The Kourovka notebook: unsolved problems in group theory. 16th edn. Russian Academy of Sciences Siberian Division, Institute of Mathematics, Novosibirsk (2006) · Zbl 1084.20001
[12] Lennox J.C., Robinson D.J.S.: The theory of infinite soluble groups. Oxford Mathematical Monographs. Oxford University Press, Oxford (2004) · Zbl 1059.20001
[13] Lubotzky A., Segal D.: Subgroup growth. Progress in Mathematics 212. Birkhaüser Verlag, Basel (2003) · Zbl 1071.20033
[14] Robinson D.J.S., Russo A., Vincenzi G.: On groups which contain no HNN-extensions. Int. J. Algebra Comput. 17, 1–11 (2007) · Zbl 1156.20023 · doi:10.1142/S0218196707004311
[15] Robinson D.J.S., Russo A., Vincenzi G.: On groups whose subgroups are closed in the profinite topology. J. Pure Appl. Algebra 213, 421–429 (2009) · Zbl 1163.20020 · doi:10.1016/j.jpaa.2008.07.015
[16] Scott P.: Correction to: ”Subgroups of surface groups are almost geometric”. J. Lond. Math. Soc. 32, 217–220 (1985) · Zbl 0581.57005 · doi:10.1112/jlms/s2-32.2.217
[17] Wehrfritz B.A.F.: Infinite linear groups. Ergebnisse der Matematik und ihrer Grenzgebiete, Band 76. Springer, New York (1973) · Zbl 0261.20038
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.