Three days of computational methods for extremal discrete geometry

The aim of the workshop is to bring together senior and especially junior researchers who work on optimization problems in discrete geometry (like for instance sphere packing or energy minimization). The focus will be on computational and experimental mathematical techniques. With short talks and many discussions we want share our computational tools, find their current limitations, and identify exciting problems which might help to shape the field in the near future.


Hotel: Hotel Flandrischer Hof

Wednesday: Übungsraum 2, Gyrhofstraße 8, 50931 Köln.

The entrance of the building ist located on its backside, please use the one on the „long“ side, directly adjacent to the parking lot. Upon entering you use the door on the far left side, after that you will find the room on the far left side.

Thursday/Friday: Room 1.03, RRZK Universität zu Köln, Weyertal 121, 50931 Köln.

Public Transport:

We recommend if you want to plan your trip.

Tramstop Sülz Universität, line STR 9 (you can reach this by taking line STR 18 from Cologne central station to Neumarkt, where you can switch to line STR 9. Alternatively, if you arrive at Köln Messe/Deutz you can use line STR 9 directly from there.)


Wednesday, November 30

11:00-12:00Arrival and coffee
12:00-13:30Lunch break
13:30-14:15A new kind of packing and coveringMarkus Faulhuber
14:30-15:00News approaches to PolarizationJan Rolfes
15:00-15:30Coffee break
17:30 Evening program

Thursday, December 1

09:30-10:15Optimization hierarchies for distance-avoiding setsFernando de Oliveira Filho
10:15-10:45Coffee break
10:45-11:15Asymptotic convergence of k-point bounds on compact packing graphsBram Bekker
11:30-12:00Evaluating the connectivity of a graph using semidefinite programmingMelanie Siebenhofer
12:00-13:30Lunch break
13:30-14:15Computing spectral bounds for geometric graphs via polynomial optimizationPhilippe Moustrou
14:30-15:00New lower bounds on crossing numbers of K_{m,n} from permutation modules and semidefinite programmingDaniel Brosch
15:00-15:30Coffee break
ab 17:30Reception and evening program

Friday, December 2

09:30-10:15The Lasserre hierarchy for equiangular lines with a fixed angleWillem de Muinck Keizer
10:15-10:45Coffee break
10:45-11:15A specialized SDP solver for sums-of-squares problems in discrete geometryNando Leijenhorst
11:30-12:00Three-point bounds for sphere packingDavid de Laat
12:00-13:30Lunch break
13:30-14:15The Coclique Number of Orthogonality GraphsFerdinand Ihringer
14:30-15:00Least Euclidean Distortion Embeddings of Flat ToriArne Heimendahl


  • Bram Bekker, TU Delft
  • Daniel Brosch, Universität Klagenfurt
  • David de Laat, TU Delft
  • Willem de Muinck, TU Delft
  • Markus Faulhuber, Universität Wien
  • Toni Golian, Universität zu Köln
  • Arne Heimendahl, Universität zu Köln
  • Ferdinand Ihringer, Universiteit Gent
  • Nando Leijenhorst, TU Delft
  • Karla Leipold, Universität zu Köln
  • Sebastian Miebach, Universität zu Köln
  • Philippe Moustrou, Université de Toulouse
  • Fernando Oliveira, TU Delft
  • Jana Pier, Universität zu Köln
  • Jan Hendrik Rolfes, KTH Stockholm
  • Robert Schüler, Universität Rostock
  • Melanie Siebenhofer, Universität Klagenfurt
  • Andreas Spomer, Universität zu Köln
  • Frank Vallentin, Universität zu Köln
  • Steffen Weißbach, Universität zu Köln
  • Angelika Wiegele, Universität Klagenfurt
  • Marc Christian Zimmermann, Universität zu Köln

Organization: Annette Koenen, Frank Vallentin, Marc Christian Zimmermann