Abstract
We describe elementary examples of finitely presented sofic groups which are not residually amenable (and thus not initially subamenable or LEA, for short). We ask if an amalgam of two amenable groups over a finite subgroup is residually amenable and answer this positively for some special cases, including countable locally finite groups, residually nilpotent groups and others.
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References
Bekka B, de la Harpe P and Valette A, Kazhdan’s property (T), New Math. Monogr. 11 CUP (2008)
Berlai F, Residual properties of free products, arXiv:1405.0244
Capraro V and Lupini M, Introduction to Sofic and hyperlinear groups and Connes’ embedding conjecture, arXiv:1309.2034
Collins B and Dykema K J, Free products of sofic groups with amalgamation over monotileably amenable groups, Münster. J. Math. 4 (2011) 101–117
Cornulier Y, A sofic group away from amenable groups, Math. Ann. 350 (2) (2011) 269–275
Elek G and Szabo E, Sofic representations of amenable groups, Proc. Amer. Math. Soc. 139 (12) (2011) 4285–4291
Eymard P, Moyennes invariantes et representations unitaires, Lecture Notes in Mathematics 300 (1972) (Berlin: Springer-Verlag)
Glasner Y and Monod N, Amenable action, free products and a fixed point property, Bull. Lond. Math. Soc. 39 (1) (2007) 138–150
Gromov M, Endomorphisms of symbolic algebraic varieties, J. European Math. Soc. 1 (2) (1999) 109–197
Paunescu L, On sofic actions and equivalence relations, J. Funct. Anal. 261 (9) (2011) 2461–2485
Scott P and Wall T, Topological methods in group theory, homological group theory, LMS Lecture Notes Series 36. CUP (1979)
Serre J P, Trees, Springer Monographs in Mathematics (2003)
Acknowledgements
The authors would like to thank the referee for pointing out the validity of the second sentence of Theorem 1 and for many suggestions which improved the presentation.
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KAR, A., NIKOLOV, N. A non-LEA sofic group. Proc Math Sci 127, 289–293 (2017). https://doi.org/10.1007/s12044-016-0315-2
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DOI: https://doi.org/10.1007/s12044-016-0315-2