Second conference on Geometric Science of Information, October 28-30 2015.

Conference on Explicit methods in Number Theory, July 6-10, 2015, Oberwolfach (Germany).

Conference Curve 2015, June 22-26 2015, Paris Jussieu.

Programm "Amplitudes, Motives and Beyond", May 26-June 12 2015, Mainz Institute for Theoretical Physics.

Number theory seminar Cologne, April 27 2015.

MPI Bonn, Manin's Seminar on Algebra, Geometry and Physics, March 10 2015.

Workshop on "Regulators, Mahler measures, and special values of L-functions", February 16-20 2015, Montreal.

Research stay at the MPI Bonn, January-September 2015.

Workshop on "Multiple Zeta Values, Modular Forms and Elliptic Motives II", December 2014, ICMAT Madrid.

Workshop on "Cohomological Realizations of Motives", 7-12 December 2014, Banff International Research Station.

Université de Fribourg (Colloquium)

Groups in Galway (Workshop), May 2014.

Fall semester on "Physics and Mathematics of Scattering Amplitudes", August - December 2013, Simons Center, New York

Autumn school on "Multiple Zeta Values, Multiple Polylogarithms and Quantum Field Theory", October 7-11, 2013, ICMAT Madrid

Clay Mathematics Institute Workshop on "Number Theory and Physics", September 30 - October 4, 2013, Oxford

Exploratory workshop on "New Approaches To Multiple Zeta Values", September 30 - October 2, 2013, ICMAT Madrid

AIM SQuaRES Workshop on "Explicit Computations with Reduction Theories III", September 16-20, 2013, American Institute for Mathematics, Palo Alto

Conference on The Mathematical Legacy of Jean-Louis Loday, September 4-6, 2013, Strasbourg

Conference on Explicit methods in Number Theory, July 14-20, 2013, Oberwolfach (Germany)

LMS Symposium on "Polylogarithms as a Bridge between Number Theory and Particle Physics", July 3-12, 2013, Durham

Conference on Recent advances in Hodge theory: Period domains, algebraic cycles, and arithmetic, June 10-20, 2013, at the UBC, Vancouver

Workshop on Amplitudes 2013, April 28 - May 3, 2013, at Ringberg Castle (Tegernsee)

Special semester on Grothendieck-Teichmüller Groups, Deformation and Operads, Jan 3- April 26 2013, at the Newton Institute in Cambridge

Workshop on Amplitudes and Periods, December 3-7 2012, at the IHES in Paris

Heilbronn Workshop on String Theory and Arithmetic Geometry, September 3-7 2012, at the Heilbronn Institute in Bristol

Workshop Periods and Motives July 2-5 2012, at the ICMAT in Madrid

Special session of the Seminaire Mediterraneen d'Algebre et Topologie (in honour of J.-L. Cathelineau) on Polylogarithms in Algebra and Topology, June 14-16 2012, in Nice

Conference on Arakelov Geometry and K-theory, May 21-23 2012, in Toulouse

AIM SQuaRES Workshop on "Explicit Computations with Reduction Theories II", American Institute for Mathematics, Palo Alto, February 2012

Workshop "Theorie des nombres et applications", January 16-20 2012, at the CIRM in Luminy

Workshop on (Polylogarithmic) Webs, the so-called Journees Textiles, November 22-25 2011, in Rennes

North British Mathematical Physics Seminar, October 29, 2011, in Durham

Explicit Methods in Number Theory, Oberwolfach July 17-23, 2011

Arbeitstagung Bonn 2011 (June 24-30), Bonn

Conference May 2-6 2011 in Bristol (with a poster), organised jointly with Richard Hain, sponsored by the Heilbronn Institute, on "Multiple zeta values, modular forms, and elliptic motives"

AIM SQuaRES Workshop on "Explicit Computations with Reduction Theories I", American Institute for Mathematics, Palo Alto, February 2011

Workshop on ``Numbers, Periods and Quantum Field Theory'' , 15-17 April 2010 (Durham)

Special Event: Jan 8.-10., 2008, "Hopf algebras and periods in QFT"

Special Event: Dec 12, 2007, "Feynman Graphs and Periods Day"

Special Event: Dec 5, 2007, "Multiple Polylogarithms and Moduli Spaces Day"

Special Semester on "Periods in Geometry, Arithmetic and Physics"