Cette Note construit un groupe W de type fini dont la croissance des boules est exponentielle, mais pour laquelle l'infimum des taux de croissance vaut 1 – en d'autres termes, W est de croissance exponentielle non-uniforme.
Ceci répond à une question de Mikhael Gromov (Structures métriques pour les variétés riemanniennes, in : J. Lafontaine, P. Pansu (Eds.), CEDIC, Paris, 1981).
Cette construction donne aussi un groupe de croissance intermédiaire V ressemblant localement à W dans le sens que (en changeant le système générateur de W) des boules de rayon arbitrairement grand coïncident dans les graphes de Cayley de V et W.
This Note constructs a finitely generated group W whose word-growth is exponential, but for which the infimum of the growth rates over all finite generating sets is 1 – in other words, of non-uniformly exponential growth.
This answers a question by Mikhael Gromov (Structures métriques pour les variétés riemanniennes, in: J. Lafontaine, P. Pansu (Eds.), CEDIC, Paris, 1981).
The construction also yields a group of intermediate growth V that locally resembles W in that (by changing the generating set of W) there are isomorphic balls of arbitrarily large radius in V and W's Cayley graphs.
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@article{CRMATH_2003__336_7_549_0, author = {Bartholdi, Laurent}, title = {A {Wilson} group of non-uniformly exponential growth}, journal = {Comptes Rendus. Math\'ematique}, pages = {549--554}, publisher = {Elsevier}, volume = {336}, number = {7}, year = {2003}, doi = {10.1016/S1631-073X(03)00131-6}, language = {en}, url = {http://www.numdam.org/articles/10.1016/S1631-073X(03)00131-6/} }
TY - JOUR AU - Bartholdi, Laurent TI - A Wilson group of non-uniformly exponential growth JO - Comptes Rendus. Mathématique PY - 2003 SP - 549 EP - 554 VL - 336 IS - 7 PB - Elsevier UR - http://www.numdam.org/articles/10.1016/S1631-073X(03)00131-6/ DO - 10.1016/S1631-073X(03)00131-6 LA - en ID - CRMATH_2003__336_7_549_0 ER -
%0 Journal Article %A Bartholdi, Laurent %T A Wilson group of non-uniformly exponential growth %J Comptes Rendus. Mathématique %D 2003 %P 549-554 %V 336 %N 7 %I Elsevier %U http://www.numdam.org/articles/10.1016/S1631-073X(03)00131-6/ %R 10.1016/S1631-073X(03)00131-6 %G en %F CRMATH_2003__336_7_549_0
Bartholdi, Laurent. A Wilson group of non-uniformly exponential growth. Comptes Rendus. Mathématique, Tome 336 (2003) no. 7, pp. 549-554. doi : 10.1016/S1631-073X(03)00131-6. http://www.numdam.org/articles/10.1016/S1631-073X(03)00131-6/
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