On plus--one generated arrangements of plane conics

Abstract: In this paper, we examine the combinatorial properties of conic arrangements in the complex projective plane that possess certain quasi--homogeneous singularities. First, we introduce a new tool that enables us to characterize the property of being plus--one generated within the class of conic arrangements with some naturally chosen quasi--homogeneous singularities. Next, we present a classification result on plus--one generated conic arrangements admitting only nodes and tacnodes as singularities. Building on results regarding conic arrangements with nodes and tacnodes, we present new examples of strong Ziegler pairs of conic-line arrangements -- that is, arrangements having the same strong combinatorics but distinct derivation modules.