Let G be the fundamental group of a compact nonpositively curved cube complex Y . With respect to a basepoint x, one obtains an integer-valued length function on G by counting the number of edges in a minimal length edge-path representing each group element. The growth series of G with respect to x is then defined to be the power series Gx(t) = ∑ gtℓ(g), where ℓ(g) denotes the length of g. Using the fact that G admits a suitable automatic structure, Gx(t) can be shown to be a rational function. We prove that if Y is a manifold of dimension n, then this rational function satisfies the reciprocity formula Gx(t−1) = (−1)nGx(t). We prove the formula in a more general setting, replacing the group with the fundamental groupoid, replacing the growth series with the characteristic series for a suitable regular language, and only assuming Y is Eulerian.
Scott, Richard  1
@article{10_2140_agt_2014_14_3533,
author = {Scott, Richard},
title = {Eulerian cube complexes and reciprocity},
journal = {Algebraic and Geometric Topology},
pages = {3533--3552},
year = {2014},
volume = {14},
number = {6},
doi = {10.2140/agt.2014.14.3533},
url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2014.14.3533/}
}
Scott, Richard. Eulerian cube complexes and reciprocity. Algebraic and Geometric Topology, Tome 14 (2014) no. 6, pp. 3533-3552. doi: 10.2140/agt.2014.14.3533
[1] , , Reciprocity of growth functions of Coxeter groups, Geom. Dedicata 39 (1991) 373
[2] , , , , Weighted $L^2$–cohomology of Coxeter groups, Geom. Topol. 11 (2007) 47
[3] , , , Fundamental groups of blow-ups, Adv. Math. 177 (2003) 115
[4] , Thin buildings, Geom. Topol. 10 (2006) 667
[5] , , , , , , Word processing in groups, Jones and Bartlett Publishers (1992)
[6] , , Growth functions on Fuchsian groups and the Euler characteristic, Invent. Math. 88 (1987) 1
[7] , , The geometry of cube complexes and the complexity of their fundamental groups, Topology 37 (1998) 621
[8] , , $L^2$–homology and reciprocity for right-angled Coxeter groups, Fund. Math. 214 (2011) 27
[9] , Ends of group pairs and non-positively curved cube complexes, Proc. London Math. Soc. 71 (1995) 585
[10] , , Automata-theoretic aspects of formal power series, Springer (1978)
[11] , Right-angled mock reflection and mock Artin groups, Trans. Amer. Math. Soc. 360 (2008) 4189
[12] , Rationality and reciprocity for the greedy normal form of a Coxeter group, Trans. Amer. Math. Soc. 363 (2011) 385
[13] , Cohomologie des groupes discrets, from: "Prospects in mathematics", Ann. of Math. Studies 70, Princeton Univ. Press (1971) 77
Cité par Sources :