Pierre Ohlmannn

Interests

I have mostly been working on efficiently solving (in theory) parity and mean payoff games, on problems related to stochastic transition systems (such as Markov Decision Processes or Probabilistic Automata), and have also done some work in algebraic circuit complexity theory, and dynamical systems for verification. My interests range over most of theoretical computer science, and related mathematical theories.

Publications

• Lower Bounds for Arithmetic Circuits via the Hankel Matrix, with Nathanaël Fijalkow, Guillaume Lagarde and Olivier Serre, STACS 2020
• Controlling a random population, with Nathanaël Fijalkow and Thomas Colcombet, FoSSaCS 2020, accepted for publication in LMCS special issue
• On the Monniaux Problem in Abstract Interpretation, with Nathanaël Fijalkow, Engel Lefaucheux, Joël Ouaknine, Amaury Pouly and James Worrell, SAS 2019, journal version under review
• The complexity of mean payoff games using universal graphs, with Nathanaël Fijalkow and Paweł Gawrychowski
• Tight Bounds using Hankel Matrix for Arithmetic Circuits with Unique Parse Trees, with Nathanaël Fijalkow and Guillaume Lagarde, journal version accepted for publication in Computational Complexity, undergoing minor changes
• Complete Semialgebraic Invariant Synthesis for the Kannan-Lipton Orbit Problem, with Nathanaël Fijalkow, Joël Ouaknine, Amaury Pouly and James Worrell, STACS 2017, journal version published in special issue of Theory of Computer Science
• A symmetric attractor-decomposition lifting algorithm for parity games , with Marcin Jurdziński, Rémi Morvan and K. S. Thejaswini, publication in progress
• Distribution-based search for Programming by Example, with Nathanaël Fijalkow and Guillaume Lagarde, publication in progress
• The theory of universal graphs for infinite duration games, with Nathanaël Fijalkow and Thomas Colcombet, publication in progress

Automata Seminar

I am also on of the organizers of the automata seminar at IRIF, so feel free to write to me about this. To subscribe to our mailing list, please follow this link and make a request.

Here and there (updated May 2020)

• Sep 2018 to Aug 2021, several visits to my PhD advisor Nathanaël Fijalkow in LABRI (Bordeaux, France)
• Nov 2020, gave a talk at Spotlight on Games Workshop 2020 (held online)
• Sep 2020, gave a talk at Highlights of Logics, Games and Automata 2020 (held online)
• Feb 2020 to Apr 2020, visited Marcin Jurdzinski and Dmitry Chistikov at the University of Warwick (Coventry, UK)
• Mar 2020, gave a talk at Symposium on Theoretical Aspects of Computer Science (Montpellier, France)
• Sept 2019, gave a talk at Highlights of Logics, Games and Automata (Warsaw, Poland)
• Sept 2019, gave a talk at International Conference on Reachability Problems (Brussels, Belgium)
• Jun 2019, attended Caleidoscope (Paris, France)
• Mar 2019, attended Bellairs workshop on Learning and Verification (Holetown, Barbados)
• Jan 2019, attended Complexity, Algorithms, Automata and Logic Meet (Chennai, India)
• Oct 2018, attended Foundations of Computer Science (Paris, France)
• Oct 2018, gave a talk at FiLOFOCS (Paris, France)
• Sept 2018, gave a talk at Highlights of Logics, Games and Automata (Berlin, Germany)
• Mar 2018, gave a talk at Workshop on Algebraic Complexity Theory (Paris, France)
• Mar 2017, gave a talk at Symposium on Theoretical Aspects of Computer Science (Hannover, Germany)
• Jun 2017, attended School on Foundations of Probabilistic Programming (Braga, Portugal)
• See my resume for a more detailed list of seminar talks I gave (mostly in France)

Some (recent) slides

• Controlling a random population
• Arithmetic circuit lower bounds via Hankel matrix
• Solving mean payoff games with universal graphs

• 2020-2021, Teacher assistant in :
  • Principles of Computing Systems - Université de Paris
  • Introduction to Programming in Java - Université de Paris
  • Professionalizing project - Université de Paris
• 2019-2020, Teacher assistant in :
  • Foundations of Automata Theory - Université Paris-Diderot
  • Introduction to Programming in Python - Université Paris-Diderot
• 2018-2019, Teacher assistant in:
  • Introduction to Object-Oriented Programing - Université Paris-Diderot
  • Introduction to Programming in Python - Université Paris-Diderot