### Recent Submissions

• #### On a Group Functor Describing Invariants of Algebraic Surfaces ﻿

[OWP-2019-08] (Mathematisches Forschungsinstitut Oberwolfach, 2019-03-01)
Liedtke (2008) has introduced group functors $K$ and $\tilde K$, which are used in the context of describing certain invariants for complex algebraic surfaces. He proved that these functors are connected to the theory of ...
• #### Weighted Surface Algebras: General Version ﻿

[OWP-2019-07] (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-28)
We introduce general weighted surface algebras of triangulated surfaces with arbitrarily oriented triangles and describe their basic properties. In particular, we prove that all these algebras, except the singular disc, ...
• #### Group Algebras of Compact Groups. A New Way of Producing Group Hopf Algebras over Real and Complex Fields: Weakly Complete Topological Vector Spaces ﻿

[OWP-2019-06] (Mathematisches Forschungsinstitut Oberwolfach, 2019-02-27)
• #### Cataland: Why the Fuß? ﻿

[OWP-2019-01] (Mathematisches Forschungsinstitut Oberwolfach, 2019-01-21)
The three main objects in noncrossing Catalan combinatorics associated to a finite Coxeter system are noncrossing partitions, clusters, and sortable elements. The first two of these have known Fuß-Catalan generalizations. ...