Conference Witt vectors in Algebra and Geometry, Moscow, Russia September 2020 Conference Noncommutative shapes (in honor of Michel Van den Bergh's 60th birthday), Antwerp, Belgium September 2020 Summer school Motivic, equivariant, and noncommutative homotopy theory, IHES, France (Course of several lectures) July 2020 JAMI Workshop Riemann-Roch in characteristic one and related topics, Johns Hopkins University October 2019 Conference The geometry of derived categories, Liverpool, United Kingdom September 2019 Workshop Algebraic K-theory, Oberwolfach, Germany June 2019 Algebraic Geometry seminar, Warwick, United Kingdom January 2019 Colloquium, University of Toronto January 2019 Algebraic and Tropical Geometry seminar, Yale University November 2018 Colloquium, Yale University November 2018 Conference Equivariant and motivic homotopy theory, Isaac Newton Institute, Cambridge, United Kingdom August 2018 Algebra and Number theory day, Johns Hopkins University April 2018 Arbeitsgemeinschaft: Topological Cyclic Homology, Oberwolfach, Germany April 2018 Algebra and Topology seminar, Universite Strasbourg, France January 2018 Colloquium, University of California at Santa Barbara  January 2018 Colloquium, University of California at San Diego December 2017 Conference Vector bundles and algebraic curves (VBAC 2017), Essen, Germany (Course of four lectures) September 2017 Mathematische Arbeitstagung 2017 (in honor of Yuri I. Manin's 80th birthday), Max-Planck-Institut fur Mathematik, Bonn, Germany June 2017 Workshop K-theory in algebraic geometry and number theory, Hausdorff Research Institute for Mathematics, Bonn, Germany May 2017 Conference Algebro-Geometric and Homotopical Methods, Institut Mittag-Leffler, Sweden March 2017 Colloquium, University of Southern California February 2017 Colloquium, Institut de Mathematiques de Jussieu, Paris, France January 2017 Algebraic Topology seminar, Universite Paris 13, France January 2017 Conference Noncommutative, derived and homotopical methods in geometry, Antwerp, Belgium September 2016 International K-theory Conference, Sydney, Australia August 2016 Conference Interacting Algebraic Geometry, Dijon, France July 2016 Workshop Algebraic K-theory and motivic cohomology, Oberwolfach, Germany June 2016 Workshop Triangulated Categories and Applications, Banff Institute, Canada June 2016 Geometry, physics, and representation theory seminar, Northeastern University April 2016 Conference Mid-Atlantic Topology, Johns Hopkins University March 2016 Conference Motives, Tokyo, Japan February 2016 Algebraic Geometry seminar, Universita degli Studi di Milano, Italy July 2015 Colloquium, University of California at Los Angeles February 2015 Workshop Cohomological Realizations of Motives, Banff Institute, Canada December 2014 Colloquium, University of Maryland October 2014 Algebra and Number Theory seminar, University of Maryland October 2014 Conference K-theory and related topics, Beijing, China August 2014 Conference Reimagining the Foundations of Algebraic Topology, MSRI, Berkeley April 2014 Algebraic Geometry seminar, California Institute of Technology January 2014 Colloquium, California Institute of Technology January 2014 Infinite Dimensional Algebraic Geometry seminar, Yale University September 2013 Conference Homotopical methods in algebraic geometry, University of Southern California June 2013 Colloquium, University of California, Berkeley May 2013 Conference Interactions between Noncommutative Algebra, Representation Theory, and Algebraic Geometry, MSRI, Berkeley April 2013   Conference Motives, Tokyo, Japan December 2012 Conference Algebraic Topology, Arolla, Switzerland August 2012 Conference Periods and Motives, Madrid, Spain July 2012 Conference Noncommutative Algebraic Geometry and its Applications to Physics, Leiden, Netherlands March 2012 Colloquium, California Institute of Technology January 2012 Algebraic Topology seminar, Massachusetts Institute of Technology November 2011 Seminar on Algebra, Geometry and Physics, Max-Planck-Institut fur Mathematik, Germany July 2011 Conference Triangulated categories and applications, Banff Institute, Canada June 2011 Representation Theory seminar, Northeastern University April 2011 Midwest Topology conference, University of Chicago April 2011 Geometric Langlands seminar, University of Chicago April 2011 Noncommutative Geometry seminar, California Institute of Technology March 2011   Noncommutative Algebraic Geometry seminar, Massachusetts Institute of Technology January 2011  Conference Homotopy theory and derived algebraic geometry, Fields Institute, Toronto, Canada August 2010   Conference Topics in Noncommutative Geometry, Buenos Aires, Argentine July 2010 Algebraic Topology seminar, Northwestern University May 2010 Algebraic Topology seminar, University of Illinois at Urbana-Champaign April 2010 Algebraic Topology seminar, University of Chicago April 2010 Algebraic Topology seminar, Massachusetts Institute of Technology March 2010 Algebraic Topology seminar, Stanford University May 2009 Algebra seminar, University of California at Los Angeles May 2009 Conference Cats 3, Centro di Ricerca Matematica Ennio De Giorgi, Pisa, Italy September 2008 Algebraic Topology seminar,  University of Bonn, Germany July 2008  Conference Homotopy Structures in Geometry and Algebra, Centre de Recerca Matematica, Barcelona, Spain June 2008 Algebra seminar, Laboratoire J. A. Dieudonne, Nice, France April 2008