Stefan Weltge

Previously

• Postdoc at ETH Zurich, 2016-2018
• PhD at University of Magdeburg, 2016

Research interests

• Discrete Optimization
• Combinatorial Optimization
• Linear and Integer Programming
• Polyhedral Combinatorics

Publications

• Lattice-free simplices with lattice width 2d - o(d)
  with Lukas Mayrhofer, Jamico Schade
  submitted, 2021
• A simple method for convex optimization in the oracle model
  with Daniel Dadush, Christopher Hojny, Sophie Huiberts
  submitted, 2021
• Integer programs with bounded subdeterminants and two nonzeros per row
  with Samuel Fiorini, Gwenaël Joret, Yelena Yuditsky
  to appear at FOCS, 2021
  
• Lifts for Voronoi cells of lattices
  with Matthias Schymura, Ina Seidel
  submitted, 2021
  
• Persistency of linear programming relaxations for the stable set problem
  with Elisabeth Rodríguez-Heck, Karl Stickler, Matthias Walter
  Mathematical Programming, 2021
  Conference on Integer Programming and Combinatorial Optimization (IPCO), 2020
• Extended formulations for stable set polytopes of graphs without two disjoint odd dycles
  with Michele Conforti, Samuel Fiorini, Tony Huynh
  Mathematical Programming, 2021
  Conference on Integer Programming and Combinatorial Optimization (IPCO), 2020
• Minimum-cost integer circulations in given homology classes
  with Sarah Morell, Ina Seidel
  Symposium on Discrete Algorithms (SODA), 2021
• Improved lower bound on the dimension of the EU council's voting rules
  with Stefan Kober
  Optimization Letters, 15, 1293–1302, 2021
• Binary scalar products
  with Andrey Kupavskii
  submitted, 2020
• Strengthening convex relaxations of 0/1-sets using Boolean formulas
  with Samuel Fiorini, Tony Huynh
  Mathematical Programming, 2020
• The stable set problem in graphs with bounded genus and bounded odd cycle packing number
  with Michele Conforti, Samuel Fiorini, Tony Huynh, Gwenaël Joret
  Symposium on Discrete Algorithms (SODA), 2020
• Distances between optimal solutions of mixed-integer programs
  with Joseph Paat, Robert Weismantel
  Mathematical Programming, 179(1), 455-468, 2020
• Extended formulations for radial cones
  with Matthias Walter
  Operations Research Letters, 47(5), 458-463, 2019
• Characterizing polytopes in the 0/1-cube with bounded Chvátal-Gomory rank
  with Yohann Benchetrit, Samuel Fiorini, Tony Huynh
  Mathematics of Operations Research, 43(3), 718-725, 2018
• Maximum semidefinite and linear extension complexity of families of polytopes
  with Gennadiy Averkov, Volker Kaibel
  Mathematical Programming, 167(2), 381-394, 2018
• Lifting linear extension complexity bounds to the mixed-integer setting
  with Alfonso Cevallos, Rico Zenklusen
  Symposium on Discrete Algorithms (SODA), 2018
• Extension complexities of Cartesian products involving a pyramid
  with Hans Raj Tiwary, Rico Zenklusen
  Information Processing Letters, 128, 11-13, 2017
• Optimality certificates for convex minimization and Helly numbers
  with Amitabh Basu, Michele Conforti, Gerard Cornuéjols, Robert Weismantel
  Operations Research Letters, 45(6), 671-674, 2017
• Notions of maximality for integral lattice-free polyhedra: the case of dimension three
  with Gennadiy Averkov, Jan Krümpelmann
  Mathematics of Operations Research, 42(4), 1035-1062, 2017
• Tight bounds on discrete quantitative Helly numbers
  with Gennadiy Averkov, Bernardo González Merino, Ingo Paschke, Matthias Schymura
  Advances in Applied Mathematics, 89, 76-101, 2017
• Three enhancements for optimization-based bound tightening
  with Ambros Gleixner, Timo Berthold, Benjamin Müller
  Journal of Global Optimization, 67 (4), 731-757, 2017
• Sizes of linear descriptions in combinatorial optimization
  Dissertation, Otto-von-Guericke-Universität Magdeburg, 2016
  (winner of the Dissertation Award 2016 of the University of Magdeburg)
• Subgraph polytopes and independence polytopes of count matroids
  with Michele Conforti, Volker Kaibel, Matthias Walter
  Operations Research Letters, 43 (5), 457-460, 2015
• Lower bounds on the sizes of integer programs without additional variables
  with Volker Kaibel
  Mathematical Programming, 154 (1-2), 407-425, 2015
  Conference on Integer Programming and Combinatorial Optimization (IPCO), 2014
• Hidden vertices in extensions of polytopes
  with Kanstantsin Pashkovich
  Operations Research Letters, 43 (2), 161-164, 2015
• A short proof that the extension complexity of the correlation polytope grows exponentially
  with Volker Kaibel
  Discrete & Computational Geometry, 53 (2), 396-401, 2015
• Learning and propagating Lagrangian variable bounds for mixed-integer nonlinear programming
  with Ambros Gleixner
  International Conference on AI and OR Techniques in Constraint Programming (CPAIOR), 2013
• Erweiterte Formulierungen für das Alternaeder
  Diploma Thesis, Otto-von-Guericke-Universität Magdeburg, 2012

PhD students

• Soroush Fatemianaraki (with Martin Grunow)
• Stefan Kober
• Jamico Schade
• Ina Seidel

Funding

• DFG Individual Research Grant: NextGen, 2021-2023
• DFG PhD Program: AdONE, 2017-2022

Contact

• Email: weltge@tum.de
• Phone: +49 89 289 16861
• Office: 02.04.040
Prof. Dr. Stefan Weltge
Technische Universität München
Zentrum Mathematik
Boltzmannstraße 3
85748 Garching bei München
Germany