Daniel Müllner
I work as a software developer at Cyfex in Zürich, Switzerland. Before, I was postdoc in Gunnar Carlsson's group at Stanford University. Here are my current contact details:
AddressDaniel MüllnerTobelsteig 3 8046 Zürich Switzerland e-mail: public key Research interestsComputational Topology, Topological Data Analysis |
Teaching
Software
- Python Mapper (with Aravindakshan Babu)
- fastcluster: Fast hierarchical clustering routines for R and Python
- xypdf, PDF output for diagrams in LaTEX with the XY-pic package
- PAD web interface for a paper by M. Nicolau, A. Levine and G. Carlsson
Preprints
- Daniel Müllner, Modern hierarchical, agglomerative clustering algorithms, arXiv: 1109.2378
Publications
- Daniel Müllner, fastcluster: Fast Hierarchical, Agglomerative Clustering Routines for R and Python, Journal of Statistical Software 53 (2013), no. 9, 1–18
- Daniel Müllner, Orientation reversal of manifolds, Algebr. Geom. Topol. 9 (2009), no. 4, 2361–2390
Dissertation: Orientation reversal of manifolds
Advisor: Prof. Matthias KreckI study the phenomenon of chirality in the context of manifolds. A connected, orientable manifold is called amphicheiral if it admits an orientation-reversing self-map and chiral if it does not. Many familiar manifolds like spheres or orientable surfaces are amphicheiral: they can be embedded mirror-symmetrically into Rn, as the following figure illustrates.
Reflect at the equator: |
Similarly | |||||
and | |||||
On the other hand, examples of chiral manifolds have been known for many decades, e. g. the complex projective spaces CP2k and some lens spaces in dimensions congruent 3 mod 4. A fundamental question was in which dimensions chiral manifolds exist. While every manifold in dimensions 1 and 2 is amphicheiral, one of my results is that in all other dimensions there exist chiral manifolds.
For more information, read a summary or the dissertation itself:
- Daniel Müllner, Orientation reversal of manifolds, Bonner Mathematische Schriften, vol. 392, Bonn, 2009