The following is a selection of recent and forthcoming talks.

Total NP Search Problems of Bounded Arithmetic and Hard Propositional Principles. Invited talk in the University of Leeds Algebra, Logic, and Algorithms Seminar, University of Leeds, UK, February 2018.
Invited speaker at Proof Complexity, Dagstuhl, Germany, January 2018.
Invited speaker at Prague Bounded Arithmetic Workshop 2017, Institute of Mathematics of the ASCR, Czech Republic, November 2017.
Provably Total NP Search Problems of Bounded Arithmetic and beyond. Invited talk in the JAIST Logic Seminar Series, JAIST, Japan, September 2017.
Invited speaker at Omni Buss Celebrations, University of California at San Diego, CA, July 2017
Invited speaker at CiE Day Lectures in Milan, University of Milan, Italy, April 2017.
Invited speaker at workshop Operations, Sets, and Types (OST 17), University of Bern, Switzerland, March 2017.
Provably total NP search problems of bounded arithmetic. Invited talk in the seminar of the Computer Science Department, University of Oxford, UK, January 2017.
Provably total NP search problems of bounded arithmetic. Invited talk in the seminar of the Computer Science Department, Royal Holloway, UK, January 2017.
Invited speaker at workshop Logic, Complexity and Automation, Computational Logic in the Alps 2016, Obergurgl University Center, Tyrol, Austria, September 2016.
Invited speaker at workshop on Proof Complexity, Chebyshev Laboratory, St.Petersburg State University, Russia, May 2016.
Provably total NP search problems in strong theories. Invited talk in the Logic Seminar of the Institute of Mathematics of the Academy of Sciences of the Czech Republic, April 2016.
Invited speaker at Workshop on Efficient and Natural Proof Systems. University of Bath, UK, December 2015.
Bounded Kripke Platek Set Theory. Invited talk in the Logic Seminar of the Institute of Mathematics of the Academy of Sciences of the Czech Republic, June 2015
Invited participant at Programme Sets and Computations, Institute for Mathematical Sciences, National University of Singapore, April 2015.
Invited participant at MFO workshop Mathematical Logic: Proof Theory, Constructive Mathematics, Oberwolfach, Germany, November 2014.
Invited speaker at Infinity Workshop, Kurt Gödel Research Center, Vienna, Austria, July 2014.
Parity Games and Propositional Proofs. Invited talk in the seminar of the Research Center for Software Verification, JAIST, Japan, January 2014
Talk on Parity Games and Propositional Proofs. 38th International Symposium on Mathematical Foundations of Computer Science, MFCS 2013, Klosterneuburg, Austria, August 26-30, 2013.
Invited speaker at Sy David Friedman’s 60th-Birthday Conference, Kurt Gödel Research Center, Vienna, Austria, July 2013.
Invited talk at the Department of Mathematics, UCSD La Jolla, California, USA, April 2013.
Invited speaker at 3rd Workshop on Proof Theory and Rewriting, JAIST, Kanazawa, Japan, March 2013.
Invited speaker at workshop Limits of Theorem Proving, Rom, 25.-27. September 2012.
Invited participant at Kotlarski Ratajczyk Conference, Bedlewo, Poland, 23.-27. July 2012.
Invited speaker at Special Session in Proof Theory at the Logic Colloquium 2012, Manchester, 12th-18th July 2012.
Invited participant at MFO workshop Mathematical Logic: Proof Theory, Constructive Mathematics, Oberwolfach, Germany, 6.-12. November 2011.
Invited participant at Proof Complexity workshop at Banff International Research Station for Mathematical Innovation and Discovery (BIRS), Canada, October 2011.
Invited speaker at Logic and Analysis Seminar at University of Gent, Belgium, August 2011.
Invited Speaker at Multi-dimension Seminar, JAIST, Japan, August 2011.
Invited talk at Infinity Conference
at Centre de Recerca Matemàtica. Facultat de Ciències. UAB. Bellaterra (Barcelona), Spain, July 2011.
Invited participant at Infinity Project at Centre de Recerca Matemàtica. Facultat de Ciències. UAB. Bellaterra (Barcelona), Spain, February 2011.
Invited participant at Workshop Barriers in computational complexity in Princeton, NJ, USA, 25-29 August 2009. This will be part of the activities of the Intractability Center.
Invited Speaker at Leeds Symposium on Proof Theory and Constructivism in Leeds, UK, 3-16 July 2009.
Invited Speaker at 16th Workshop on Logic, Language, Information and Computation in Tokyo, Japan, 21-24 June 2009.
Invited Speaker at Kobe Logic Seminar Japan, 18 June 2009.
Invited Speaker at Set Theory and its Neighbours: Set Theory, Games & Arithmetic in Bristol, UK, 19 November 2008.
Conference Visions of Computer Science at Imperial College London, 22-24 September 2008. Talk: On the complexity of parity games.
Invited speaker at the PohlersFest in Münster, Germany, 18 July 2008. See here for a list of contributions to the Festschrift “Ways of Proof Theory”.
Invited speaker at Workshop on proof theory in Bern, Switzerland, 9-11 July 2008.
Speaker at LICS 2008 in Pittsburgh, Pennsylvania, June 2008.
Invited speaker at 27th Weak Arithmetics Days in Athens, Greece, June 2008.
Participant at MFO workshop Mathematical Logic: Proof Theory, Constructive Mathematics, Oberwolfach, Germany, 6.-12. April 2008.
Workshop on proof theory in Munich, Germany, 4/5 April 2008.