Combinatorics of toric arrangements

In this paper we build an Orlik-Solomon model for the canonical gradation of the cohomology algebra with integer coefficients of the complement of a toric arrangement. We give some results on the uniqueness of the representation of arithmetic matroids, in order to discuss how the Orlik-Solomon model depends on the poset of layers. The analysis of discriminantal toric arrangements permits us to isolate certain conditions under which two toric arrangements have diffeomorphic complements. We also give combinatorial conditions determining whether the cohomology algebra is generated in degree one.

[1]  Egbert Brieskorn Sur les groupes de tresses , 1972 .

[2]  P. Orlik,et al.  Combinatorics and topology of complements of hyperplanes , 1980 .

[3]  Richard Randell,et al.  Lattice-isotopic arrangements are topologically isomorphic , 1989 .

[4]  B. Sturmfels,et al.  Binomial Ideals , 1994, alg-geom/9401001.

[5]  C. Procesi,et al.  On the geometry of toric arrangements , 2005 .

[6]  Luca Moci A Tutte polynomial for toric arrangements , 2009 .

[7]  S. Settepanella,et al.  The homotopy type of toric arrangements , 2010, 1009.3622.

[8]  Corrado De Concini,et al.  Topics in Hyperplane Arrangements, Polytopes and Box-Splines , 2010 .

[9]  Emanuele Delucchi,et al.  Minimality of toric arrangements , 2011, 1112.5041.

[10]  Luca Moci,et al.  Arithmetic matroids, the Tutte polynomial and toric arrangements , 2011 .

[11]  A Salvetti complex for Toric Arrangements and its fundamental group , 2011, 1101.4111.

[12]  Luca Moci,et al.  The multivariate arithmetic Tutte polynomial , 2012 .

[13]  Luca Moci Wonderful Models for Toric Arrangements , 2009, 0912.5461.

[14]  Cl'ement Dupont,et al.  The Orlik-Solomon model for hypersurface arrangements , 2013, 1302.2103.

[15]  Cl'ement Dupont,et al.  Purity, formality, and arrangement complements , 2015, 1505.00717.

[16]  Christin Bibby Cohomology of abelian arrangements , 2015 .

[17]  Emanuele Delucchi,et al.  The integer cohomology algebra of toric arrangements , 2015, 1504.06169.

[18]  C. Concini,et al.  Projective Wonderful Models for Toric Arrangements , 2016, 1608.08746.

[19]  Matthias Lenz Representations of Weakly Multiplicative Arithmetic Matroids are Unique , 2017, Annals of Combinatorics.