
Talks at international conferences
 "Epistemic justification after foundationalism: A generalised Bayesian approach", GAP.10 — German Society for Analytic Philosophy, Cologne, Germany, September 2018.
 "Infinitesimal justification", Topics in Scientific Philosophy, Irvine, California, United States, February 2018.*
 "Logic, probability, social choice: Some recent developments" (Keynote Lecture), Logic, Decisions, and Interactions, Lorentz Center, Leiden, The Netherlands, October 2016.
 "Respect for experts vs. respect for unanimity? News from probabilistic opinion pooling" (Invited Talk), Robust Finance and Beyond, Center for Interdisciplinary Research (ZiF) Bielefeld, Germany, May/June 2016.
 "Microeconomic foundation of representative agent models by means of ultraproducts" (with Geghard Bedrosian), 15th Society for the Advancement of Economic Theory (SAET) Conference, Cambridge, England, July 2015.
 "Respect for experts or respect for unanimity? The liberal paradox in probabilistic opinion pooling", Society for Economic Design (SED) Conference, Istanbul, Turkey, July 2015.
 "A probabilistic version of Sen’s liberal paradox" (Invited Talk), Trends in Logic XV, Delft, The Netherlands, June 2015.
 "Aggregating infinitely many priors" (Invited Talk), Mathematics and Financial Economics, Center for Interdisciplinary Research (ZiF) Bielefeld, Germany, May 2015.
 "A graded Bayesian coherence notion", Workshop 'Full and Partial Belief' (in conjunction with the 4th René Descartes Lectures), Tilburg, The Netherlands, October 2014.
 "Ultraproduct construction of representative utility functions with infinitedimensional domain" (with Geghard Bedrosian), Colloquium Logicum 2014, Neubiberg–Munich, Germany, September 2014.
 "The problem of judgment aggregation in the
framework of booleanvalued models" (with Daniel Eckert), 15th International Workshop on Computational Logic in MultiAgent Systems (CLIMA XV), Prague, Czech Republic, August 2014.
 "Booleanvalued judgment aggregation." (with Daniel Eckert), Logic, Algebra and Truth Degrees, Vienna, Austria, July 2014.
 "Ultraproduct construction of representative utility functions with infinitedimensional domain" (with Geghard Bedrosian), Logic Colloquium 2014, Vienna, Austria, July 2014.
 "The problem of judgment aggregation as a modeltheoretic preservation problem" (with Daniel Eckert), 11th Conference on Logic and the Foundations of Game and Decision Theory (LOFT 2014), Bergen, Norway, July 2014.
 "The birth of social choice theory from the spirit of mathematical logic: Arrow's theorem as a modeltheoretic preservation result 'avant la lettre'" (with Daniel Eckert), Workshop on “Individual and Collective Choices”, Munich, Germany, July 2014.
 "Arrovian aggregation of Monotonic Bernoullian Archimedean preferences: (Im)possibility results via model theory", 16th Conference on the Foundations of Utility and Risk, Rotterdam, The Netherlands, June/July 2014.*
 "Aggregating infinitely many probability measures", Imprecise Probabilities in Statistics and Philosophy, Munich, Germany, June 2014.
 "Arrovian aggregation of Monotonic Bernoullian Archimedean preferences: (Im)possibility results via model theory", Journées d'Economie Publique LouisAndré GérardVaret, Aix en Provence, France, June 2014.
 "Epistemic justification, formally: Alternatives to foundationalism and an exercise in mathematical philosophy" (Invited Talk), Special Session on Recent trends in History and Philosophy of Mathematics, Second Joint International Meeting of the Israeli Mathematical Union (IMU) and the American Mathematical Society (AMS), TelAviv, Israel, June 2014.
 "A simple possibility result in a Booleanvalued model for judgment aggregation" (with Daniel Eckert), 7th Workshop on Logical Aspects of MultiAgent Systems (LAMAS 2014), Paris, France, May 2014.
 "Modeltheoretic and algebraic approaches to general aggregation theory" (Invited Talk), Workshop: Judgment Aggregation for Artificial Intelligence, Schloss Dagstuhl, Germany, May 2014.
 "Arrovian Aggregation of Monotonic Bernoullian Archimedean preferences: An impossibility result", Verein für Socialpolitik, Jahrestagung 2013, Düsseldorf, Germany, September 2013.
 "Ambiguity and the aggregation of priors" (Invited Session Talk), 13th Society for the Advancement of Economic Theory (SAET) Conference, Paris, France, July 2013.
 "Stochastic calculus with infinitesimals — via a minimal fragment of nonstandard analysis" (Invited Talk), Stochastic and Real World Models 2013, Bielefeld, Germany, July 2013.
 "Arrovian Aggregation of MBA preferences: An impossibility result", XXII European Workshop on General Equilibrium Theory (EWGET 2013), Vienna, Austria, May/June 2013.
 "Aggregation prior to preference formation: How to rationally aggregate probabilities", 6th MunichSydneyTilburg conference: Models and Decisions, Munich, Germany, April 2013.
 "An algebraic resolution to a puzzle in general aggregation theory: Towards a natural aggregation theory for Bayesian priors" (Invited Talk), Workshop on Formal Practical Philosophy, Venice, Italy, November 2012.
 "On ‘The No Alternatives Argument’ by R. Dawid, S. Hartmann and J. Sprenger" (Invited Comments), 9th Annual Formal Epistemology Workshop, Munich, Germany, May/June 2012.
 "Towards ‘radically elementary’ stochastic analysis" (Invited Talk), Special Session on Applications of Nonstandard Analysis, American Mathematical Society (AMS) Western Section Meeting, Honolulu, Hawaii, United States, March 2012.
 "The (im)possibility of collective risk measurement: Arrovian aggregation of variational preferences", 2011 NSF/NBER/CEME Conference in Mathematical Economics and General Equilibrium Theory (National Science Foundation / National Bureau of Economic Research), Iowa City, United States, October 2011.
 "The (im)possibility of collective risk measurement: Aggregation theory for variational preferences" (Invited Session Talk), Stochastic and Real World Models 2011, Bielefeld, Germany, July 2011.
 "Aggregators, functional equations and homomorphisms in general aggregation theory" (Invited Session Talk), 11th Society for the Advancement of Economic Theory (SAET) Conference, Ancao (Faro), Portugal, June/July 2011.*
 "Social choice of convex risk measures through Arrovian aggregation of variational preferences", 10th Society for the Advancement of Economic Theory (SAET) Conference on Current Trends in Economics, Singapore, August 2010.
 "Impossibility results for infiniteelectorate abstract aggregation rules" (with Daniel Eckert), 9th Conference on Logic and the Foundations of Game and Decision Theory (LOFT 2010), Toulouse, France, July 2010.
 "An ultraproduct construction of a representative individual for an Arrovian social welfare function" (Invited Talk), The ChineseGerman Meeting on Stochastic Analysis and Related Fields, Beijing, China, May 2010.
 "Microfoundations for the representative agent: An application of model theory to Arrovian social choice theory" (Invited Talk), Complexity, Mathematics and Socioeconomic Problems, Center for Interdisciplinary Research (ZiF) Bielefeld, Germany, August/September 2009.
 "A representative individual from Arrovian aggregation of parametric individual utilities", 64th Econometric Society European Meeting (ESEM), Barcelona, Catalonia, Spain, August 2009.
 "Ultrafilters, ultraproducts and nonstandard analysis in social choice theory", Logic and Mathematics, York, England, August 2009.
 "Systematic judgment aggregators: An algebraic connection between social and logical structure" (with Daniel Eckert), Logical Methods for Social Concepts (LMSC'09), Bordeaux, France, July 2009.
 "Microfoundations for the representative agent via nonstandard analysis", 9th Society for the Advancement of Economic Theory (SAET) Conference on Current Trends in Economics, Ischia, Italy, June/July 2009.
 "It all depends on independence" (with Daniel Eckert), Society for Economic Design (SED) Conference on Economic Design 2009, Maastricht, The Netherlands, June 2009.
 "Pascal's Wager and hyperfinite expected utilities", Formal Methods in the Epistemology of Religion, Leuven, Belgium, June 2009.*
 "On the foundations of Lévy finance: Equilibrium for a singleagent financal market with jumps", XVIII European Workshop on General Equilibrium Theory (EWGET09), Barcelona, Spain, June 2009.*
 "A simple equilibrium model for Lévy finance", Stochastics and Real World Models, Bielefeld, Germany, May 2009.
 "Hyperfinite expected utilities and Pascal's Wager", 8th Conference on Logic and the Foundations of Game and Decision Theory (LOFT 2008), Amsterdam, The Netherlands, July 2008.
 "A definable framework for nonstandard analysis", International Congress on Applications of Ultrafilters and Ultraproducts in Mathematics (UltraMath 2008), Pisa, Italy, June 2008.
 "Purejump Lévy processes as hyperfinite superpositions of Poisson processes" (Invited Session Talk), Second SinoGerman Meeting on Stochastic Analysis, Beijing, China, March 2007.
 "Continuity corrections for certain perpetual American options on multiple assets", Special Session on Financial Mathematics, American Mathematical Society (AMS) Annual Meeting, New Orleans, Louisiana, United States, January 2007.
 "A combinatorial infinitesimal representation of Lévy processes and applications", International Congress on Nonstandard Methods in Mathematics and Applications, Pisa, Italy, May 2006.
 "Exercise regions and continuity corrections for certain perpetual American options, GermanJapanese Symposium on Dirichlet Forms, Stochastic Analysis and Interacting Particle Systems, Bielefeld and Bonn, Germany, November 2005.
 "Generalized likelihoods, ideals and infinitesimal chances", Session on Philosophy of Mathematics, Mathematical Association of America (MAA) Annual Meeting, Atlanta, Georgia, United States, January 2005.
 "Lifting Lévy processes to hyperfinite random walks", International Conference on Nonstandard Mathematics, Aveiro, Portugal, June 2004.
Invited talks at university departments
 International Academy of Philosophy (IAP) in the Principality of Liechtenstein, March 2018.
 University of Vienna (Department of Economics) & Institute for Advanced Studies, October 2017.
 University of Kent, Canterbury (School of European Culture and Languages), May 2016.
 Universität Düsseldorf (Lehrstuhl für Theoretische Philosophie), November 2015.*
 Center for Interdisciplinary Research (ZiF) Bielefeld, April 2015.
 Universität Bielefeld (Institute for Interdisciplinary Studies of Science, I^{2}SoS), May 2014.
 LudwigMaximiliansUniversität München (Fakultät für Mathematik, Informatik und Statistik), June 2013.
 Universität Jena (Fakultät für Mathematik und Informatik), April 2013.
 Universität Augsburg (Institut für Mathematik), November 2011.
 HelmutSchmidtUniversität / Universität der Bundeswehr Hamburg (Wirtschafts und Sozialwissenschaftliche Fakultät, Fachgruppe Mathematik/Statistik), October 2011.
 LudwigMaximiliansUniversität München (Fakultät für Philosophie, Wissenschaftstheorie und Religionswissenschaft, Munich Center for Mathematical Philosophy), October 2011.
 Universität Hildesheim (Institut für Mathematik und Angewandte Informatik), September 2011.
 Universität Paderborn (Institut für Mathematik), January 2011.
 Leuphana Universität Lüneburg (Präsidium), December 2010.
 Københavens Universitet (Økonomisk Institut), May 2010.*
 Technische Universität Cottbus (Institut für Mathematik), November 2009.*
 Universität Lübeck (Institut für Mathematik), September 2009.*
 Universität Augsburg (Institut für Mathematik), June 2009.
 HeinrichHeineUniversität Düsseldorf (Mathematisches Institut), May 2009.
 JuliusMaximiliansUniversität Würzburg (Institut für Mathematik), March 2009.
 KarlFranzensUniversität Graz (Institut für Volkswirtschaftslehre), December 2008.
 Universität Bielefeld (Institut für Mathematische Wirtschaftsforschung), June 2007.
 Rheinische FriedrichWilhelmsUniversität Bonn (Institut für Angewandte Mathematik), November 2006.
(Talks with an asterisk (*) were cancelled by myself due to conflicting obligations or health reasons.)
