recent preprints and papers
 Higher HasseWitt matrices [arXiv]
 Formal groups and congruences [arXiv]
 Explicit padic unitroot formulas for hypersurfaces [arXiv]
 (with Anton Mellit) Dwork's congruences for the constant terms of powers of a Laurent polynomial, International Journal of Number Theory, 2016 [arXiv]
 (with Vasily Golyshev) Equations D3 and spectral elliptic curves, in `Feynman Amplitudes, Periods and Motives`, Contemporary Mathematics 648 (2015), 135152 [arXiv]
 (with Evgeny Shinder) Linear Mahler measures and double Lvalues of modular forms, Journal of Number Theory 142 (2014), 149182 [arXiv]
 (with Don Zagier) Higher Kronecker limit formulas for real quadratic fields, Journal fur die Reine und Angewandte Mathematik 679 (2013), 2364 [pdf]
 (with Sander Zwegers) Nahm's conjecture: asymptotic computations and counterexamples, Communications in Number Theory and Physics 5 (2011), 617642 [arXiv]
 (with Kevin Hutchinson) Lines crossing a tetrahedron and the Bloch group, in `Contributions to Algebraic Geometry', IMPANGA lecture notes, EMS Series of Congress
Reports (2012), 297  304 [arXiv]
 Generalization of the Stark unit for abelian Lfunctions with multiple zeros [arXiv]

2018 
January  April, HIM Bonn, trimester program `Periods in Number
Theory, Algebraic Geometry, and Physics' 
2017 
January 828, Melbourne (Australia), program ` Hypergeometric motives and CalabiYau differential equations` 
2016 
June 28  July 1, Porquerolles (France), workshop on automata, algebraicity and Gfunctions [slides] 
 June 2025, Herstmonceux Castle (East Sussex, UK), CalabiYau varieties: arithmetic, geometry and physics 
 June 1, UAM Poznan, Algebra, geometry and arithmetic seminar [slides] 
 May 2328, IMJPRG Paris, Arithmetic Lfunctions and differential geometric methods (Regulators IV) 
 May 1214, HU Berlin, Moduli and automorphic forms, talk 'Higher HasseWitt matrices' 
 April 20, University of Gdansk, Geometry Seminar, talk 'padic properties of periods' 
2015 
November 24, University of Mainz, SFB Colloquium, talk 'Arithmetic properties of coefficients of logarithms of formal group laws' 
 November 10, Institute of Mathematics in Kyiv, Algebra Seminar, talk 'Arithmetic properties of formal groups' 
 October 23, IMPANGA, Warsaw 
 July 511, Oberwolfach, Explicit methods in number theory, talk 'Formal groups and congruences' 
 February 1620, CRM of Montréal, Regulators, Mahler measures, and special values of Lfunctions, talk 'Explicit padic unitroot formulas for hypersurfaces' 
 January 14, MPIM Bonn, Seminar on recurrences and Lvalues 
2014  November 10, University of Warwick, Number Theory Seminar, talk 'Dwork's congruences for periods of families of CalabiYau hypersurfaces' 
 September 112, ICTP Trieste, Lfunctions and modular forms
Notes of my course on MonskiWashnitzer cohomology and Kedlaya's algorithm for counting points on hyperelliptic curves over finite fields 
 August 18  22, MSRI Berkeley, New Geometric Methods in Number Theory 
 June 2327, IHES BuressurYvette, Algebra, Geometry and Physics 
 April 3, Dublin Area Mathematics Colloquium, talk 'Counting points over finite fields on CalabiYau hypersurfaces' 
 March 29, UCD Algebra and Number Theory Seminar, talk 'Congruences for the constant terms of powers of a Laurent polynomial' 
2013  July 1420, Oberwolfach, Explicit methods in number theory, talk 'Determinantal differential operators with Frobenius structure' 
 July 1012, Utrecht, Special functions and special numbers 
 June 1520, Saariselkä, Arctic Number Theory Workshop, talk 'Dwork's congruences and padic overconvergence' 
 March 1114, Dublin, 27th Automorphic Forms Workshop [slides] 
2012  December 1521, Bonn, Galois representations and pencils of CalabiYau motives, talk 'D3 equations and spectral elliptic curves' 
 November 59, Paris, Hypergeometric motives 
 August 26  September 1, Oberwolfach, Lowdimensional topology and number theory 
 July 26, ICMAT Madrid, Periods and motives: a modern perspective on renormalization [slides] 
 June 2529, ICTP Trieste, Hypergeometric motives 
 June 1314, Irish Geometry Conference, University College Cork, talk 'Geometricity problem for differential equations' 
 May 29  June 1, Paris, Hypergeometric series and their generalizations in algebra, geometry,
number theory and physics, talk 'Mahler's measure of a linear form and double Lvalues' 
 April 5, Dublin, KTheory, Quadratic Forms and Number Theory seminar at UCD 
 March 2328, MPIM Bonn, Motivic structures on quantum cohomology 
 February 27  March 1, Cologne, Modular forms, mock theta functions, and applications [slides] 
2011  July 17  July 23, 2011, Oberwolfach, Explicit methods in number theory [slides] 
