2 papers
math.CO2019
Combinatorially formal arrangements are not determined by their points and lines
Tilman Moeller
An arrangement of hyperplanes is called formal, if the relations between the hyperplanes are generated by relations in codimension 2. Formality is not a combinatorial property, rai…
math.AT2018
Restrictions of aspherical arrangements
Nils Amend, Tilman Moeller, Gerhard Roehrle
In this note we present examples of -arrangements which admit a restriction which fails to be . This shows that asphericity is not hereditary among hyperplane arran…