Piotr Pokora

A counterexample to the containment I(3) ⊂ I2 over the reals

The purpose of this note is to give counterexamples to the con- tainment I (3) I 2 over the real numbers.

Curve configurations in the projective plane and their characteristic numbers

In this paper we study the concept of characteristic numbers and Chern slopes in the context of curve configurations in the real and complex projective plane. We show that some extremal line configurations inherit the same asymptotic invariants, namely asymptotic Chern slopes and asymptotic Harbourne constants which sheds some light on relations between the bounded negativity conjecture and the geography problem for surfaces of general type. We discuss some properties of Kummer extensions, especially in the context of ball-quotients. Moreover, we prove that for a certain class of smooth curve configurations in the projective plane their characterstic numbers are bounded by

On the local negativity of surfaces with numerically trivial canonical class

8/3

On the local negativity of Enriques and K3 surfaces

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