Talks given (and to be given)

This page is subsidiary to my online curriculum vitae, but that page was already getting too long as it was, so I split this information off. For those talks given using a computer, slides are available here.

Last modified Tuesday, 07-Nov-2017 00:46:38 EST. All chronological lists sorted in reverse order, starting from the scheduled future; items not yet past are indicated in italics.

Invited attendance at conferences

This list includes all accepted invitations to attend conferences (including those I helped organize), whether or not I gave a talk; however, occasions where I did not give a talk are specifically noted.

Arithmetic, Geometry, Cryptography, and Coding Theory, CIRM, June 2019.
Arizona Winter School, Tucson, March 2019 (organizer; no talk).
CMI (Clay Mathematics Institute) at 20, Oxford, September 2018 (no talk).
Arithmetic of differential equations (summer school), Łukęcin, September 2018.
Arithmetic Algebraic Geometry, Poznań, August 2018.
L-Functions and Modular Forms Database, MIT, August 2018 (no talk).
ICM satellite conference in number theory, Rio de Janeiro, July 2018 (organizer; no talk).
Witt Vectors, Deformations, and Absolute Geometry, Vermont, July 2018 (organizer; no talk).
Algebraische Zahlentheorie, Oberwolfach, June 2018.
Birational Geometry and Arithmetic, ICERM, Providence, May 2018.
Tropical Geometry and Amoebas in Higher Dimension, IML, Stockholm, April 2018 (no talk).
Spring Lecture Series, Arkansas, April 2018 (5 talks).
Picard-Fuchs Equations and Hypergeometric Motives, Bonn, March 2018.
The Homological Conjectures: Resolved!, MSRI, March 2018.
Algebraic Geometry and Number Theory, ISI Bangalore, December 2017.

Constructing cryptographic multilinear maps, AIM, San Jose, October 2017 (no talk).
p-adic Cohomology and Arithmetic Applications, Banff, October 2017 (organizer plus talk).
Open Source Computation and Algebraic Surfaces, Banff, September-October 2017 (no talk).
Arithmetic of Hyperelliptic Curves, ICTP, Trieste, September 2017.
Sage Days, IMA, Minneapolis, August 2017.
Journées Arithmétiques, Caen, July 2017 (scientific committee; did not attend).
Arithmetic, Geometry, Cryptography, and Coding Theory, Luminy, June 2017.
L-Functions and Modular Forms Database, Warwick, June 2017 (no talk).
p-adic Hodge theory and automorphic forms, Beijing, June 2017.
Arithmetic Aspects of Explicit Moduli Problems, Banff, May-June 2017 (organizer; no talk).
The Integration of Online Materials and Online Textbooks, Tacoma, May 2017 (no talk).
Simons Symposium: p-adic Hodge Theory, Schloss Elmau, May 2017.
Seminaire Grothendieck: p-adic Hodge Theory, Zürich, May 2017.
Bridges between automatic sequences and algebra and number theory, CRM, Montréal, May 2017.
Hot topics: Galois theory of periods and applications, MSRI hot topics workshop, March 2017.
p-adic Analytic Geometry and Differential Equations, CIRM, Luminy, March 2017.
Elliptic Curves, Torsors, and L-Functions, Virginia, March 2017.
Perfectoid spaces, Arizona Winter School, March 2017 (organizer plus 4 talks plus student project).
D-modules and Hodge Theory, Tokyo, January 2017 (two talks).
Global Langlands correspondence, AIM, San Jose, December 2016 (no talk).
Fields Medal symposium: Manjul Bhargava, Fields Institute, Toronto, November 2016.
Oberwolfach Seminar: Perfectoid spaces, Oberwolfach, October 2016 (organizer plus 4 talks).
Kummer classes and anabelian geometry, Vermont, September 2016.
Automorphic Forms: Theory and Computation, King's College, London, September 2016.
Sage Days, Honolulu, August 2016 (no talk).
Elliptic curves, modular forms, and related topics, Connecticut, August 2016.
Arithmetic geometry, Oberwolfach, August 2016.
IUT Summit, RIMS, Kyoto, July 2016 (no talk).
L-functions and arithmetic, Harvard, June 2016.
The p-adic Langlands programs and related topics, Indiana, May 2016.
L-functions and modular forms database, American Institute of Mathematics, San Jose, May 2016 (no talk).
L-functions and modular forms database, Bristol, March 2016 (no talk).
Explicit p-adic methods in number theory, Oxford, March 2016 (no talk).
Recent developments in integral p-adic cohomology theories, Hausdorff Center, Bonn, February 2016.
Non-archimedean geometry and applications, Oberwolfach, December 2015.
The IUT theory of Shinichi Mochizuki, Oxford, December 2015 (two talks).
Computational aspects of L-functions, ICERM, November 2015 (no talk).
Explicit methods for modularity of K3 surfaces and other higher weight motives, ICERM, October 2015.
AGNES (Algebraic Geometry Northeastern Series), Brown, October 2015.
Modular forms and curves of low genus: computational aspects, ICERM, September-October 2015 (organizer; no talk).
p-adic Hodge theory and Iwasawa theory, Bielefeld, September 2015.
D-modules and singularities, Padova, September 2015.
Lifting problems and Galois theory, Banff, August 2015.
p-adic Hodge theory (component of AMS Summer Institute on algebraic geometry), July 2015 (session organizer plus talk).
Explicit methods in number theory, Oberwolfach, July 2015 (no talk).
Number theory and physics, IMPA, Rio de Janeiro, June 2015.
Non-archimedean geometry, Ann Arbor, June 2015.
p-adic methods in number theory, Berkeley, May 2015 (organizer plus talk).
Witt vectors and differential algebra, Berkeley, May 2015 (organizer; no talk).
Workshop on p-adic cohomology, Imperial College, March 2015.
Simons Symposium on nonarchimedean and tropical geometry, Puerto Rico, February 2015.
Valuation theory and its applications, Oberwolfach, October 2014 (no talk).
AMS Western sectional meeting, San Francisco, October 2014 (invited address).
NATO Advanced Study Institute, Ohrid, August 2014 (three talks).
Algebraic number theory, Oberwolfach, July 2014.
Sage Education Days 6, Seattle, June 2014 (organizer; no talk).
p-adic variation in number theory, Boston, June 2014 (no talk).
L-Functions and Modular Forms Database, Warwick, June 2014 (no talk).
Number fields and function fields: coalescences, contrasts and emerging applications (Royal Society meeting), Chicheley Hall, May 2014.
AMS Western sectional meeting, special session on arithmetic and differential algebraic geometry, Albuquerque, April 2014.
Curves and automorphic forms, Arizona State, March 2014.
Frobenius distributions on curves, CIRM, Luminy, February 2014.
Hot Topics: Perfectoid spaces and their applications, MSRI, February 2014.
Arithmetic statistics over number fields and function fields, AIM, January 2014 (no talk).
Sage Days: Computational Number Theory and the Cloud, Honolulu, January 2014 (no talk).
GeoCrypt: geometry and cryptography, Tahiti, October 2013 (plenary talk).
Regensburg days on non-archimedean geometry, September 2013.
Sage Days 53: Computational Number Theory, Geometry, and Physics, Oxford, September 2013 (no talk).
Conference on Stark's conjecture and related topics, UC San Diego, September 2013 (organizer; no talk).
L-functions and modular forms database (LMFDB), September 2013.
Sage Days 52: Arithmetic over Discrete Valuation Rings, Rennes, September 2013 (no talk).
Lattices with symmetry, Irvine, August 2013 (no talk).
SIAM conference on applied algebraic geometry, Colorado State, August 2013.
Explicit methods in number theory, Oberwolfach, July 2013 (no talk).
Sage Education Days 5, Seattle, June 2013 (organizer; no talk).
Motivic Invariants and Singularities, Notre Dame, June 2013.
Challenges in Combinatorics on Words, Fields Institute, Toronto, April 2013 (two plenary talks).
Computations in p-adic Hodge theory, CIRM, Luminy, April 2013 (no talk).
Special session on arithmetic statistics and big monodromy, AMS western sectional meeting, Boulder, April 2013.
Texas Algebraic Geometry Seminar, Austin, April 2013.
Non-archimedean and tropical geometry, Simons Symposium, US Virgin Islands, April 2013 (no talk).
Special session on L-functions and arithmetic geometry, AMS-MAA Joint Meetings, San Diego, January 2013 (organizer; no talk).
Special session on Witt vectors, descent, and lifting, AMS-MAA Joint Meetings, San Diego, January 2013.
Mini-workshop on arithmetic, Taipei, December 2012 (two talks).
Non-archimedean analytic geometry, Oberwolfach, November 2012.
Rational points on curves: a p-adic and computational approach, Oxford, September 2012 (no talk).
Arithmetic geometry, Oberwolfach, August 2012 (no talk).
Microsoft Research Summer Number Theory Day, Redmond, July 2012.
Algorithmic Number Theory Symposium, UC San Diego, July 2012 (organizer and program committee chair; no talk).
Hypergeometric motives, ICTP, Trieste, June 2012.
Sage Education Days 4, Seattle, June 2012 (organizer; no talk).
Barcelona-Boston-Tokyo Number Theory Seminar, Barcelona, May 2012.
Witt vectors in arithmetic, geometry, and topology, Albuquerque, May 2012 (organizer plus talk).
Pro-unipotent fundamental groups: arithmetic and diophantine aspects, Barbados, May 2012 (no talk).
The p-adic Langlands correspondence: recent developments and applications, Fields Institute, Toronto, April 2012 (no talk).
Hawaii Conference in Algebraic Number Theory, Arithmetic Geometry and Modular Forms, Hawaii, March 2012.
Special session in arithmetic geometry, AMS sectional meeting, Hawaii, March 2012.
Sage Days 36: p-adics in Sage, UC San Diego, February 2012 (organizer; no talk).
AMS Short Course, AMS-MAA Joint Meetings, Boston, January 2012 (organizer plus talk).
New Zealand Mathematical Society Colloquium and Number Theory Satellite Day, Auckland, December 2011 (plenary talk plus seminar talk).
Number theory, algebraic geometry, and model theory, CIRM (Luminy), September 2011.
L-functions and modular forms (FRG workshop), Bristol, September 2011 (no talk).
Sato-Tate in higher dimension, Benasque, July-August 2011.
LMS symposium on automorphic forms and Galois representations, Durham, July 2011 (no talk).
Explicit methods in number theory, Oberwolfach, July 2011.
Sage Education Days 3, Seattle, June 2011 (no talk).
Toric geometry and applications, Leuven, June 2011.
Théorie de Hodge p-adique, équations différentielles p-adiques et leurs applications, Lyon, June 2011.
Moduli spaces and moduli stacks, Columbia, May 2011 (no talk).
Noncongruence modular forms and Galois representations (Atkin memorial conference), UIC, April 2011.
Arithmetic statistics, MSRI, April 2011.
Noncommutative geometry and arithmetic, Johns Hopkins, March 2011.
From p-adic differential equations to arithmetic algebraic geometry, Padova, February 2011.
Witt vectors, foliations, and absolute de Rham cohomology (organizer plus talk), Nagoya, November 2010.
Southern California Number Theory Day, UC Irvine, November 2010.
Western Algebraic Geometry Symposium, U. of Arizona, November 2010.
International Congress of Mathematicians (section 3: number theory), Hyderabad, August 2010.
Galois representations in arithmetic and geometry (ICM satellite), Goa, August 2010.
Summer school on Berkovich spaces, Paris, June-July 2010 (talk cancelled due to flight delay).
Rational points: theory and experiment, Zürich, May 2010.
Point counting: theory, algorithms and practice (organizer; no talk), CRM, Montréal, April 2010.
Conférence Jean-Marc Fontaine, Paris, March 2010.
SING 2010: Resolutions of Singularities Problems, Valladolid, March 2010 (talk cancelled due to weather).
Effective methods in p-adic cohomology (organizer plus talk), Oxford, March 2010.
Galois Trimester (series of 3 lectures), Paris, January 2010.
Final workshop (Non-abelian Fundamental Groups in Arithmetic Geometry semester program), Isaac Newton Institute, Cambridge (UK), December 2009 (no talk).
Sage Days 18, Clay Math Institute, Cambridge (US), December 2009 (organizer; no talk).
p-adic geometry and homotopy theory, Loen (Norway), August 2009.
Journées de Géométrie Algébrique de Rennes, July 2009.
Arithmetic of L-functions, Park City Mathematics Institute, July 2009.
Sage Days 15, Seattle, May 2009 (no talk).
Counting points on varieties, Leiden, April 2009.
Curves, coding theory, and cryptography (ESF workshop), Luminy, March 2009 (no talk).
Conference on D-modules in honor of Zoghman Mebkhout's 60th birthday, Seville, January 2009.
Recent progress in arithmetic D-modules, Strasbourg, October 2008.
Workshop on p-adic cohomology, Mainz, September-October 2008 (series of 6 lectures).
p-adic differential equations: a conference in honor of Gilles Christol, Bressanone, September 2008.
Arithmetic geometry, Oberwolfach, August 2008.
Arithmetic Geometry, NCBS (Bangalore), March 2008.
Computational complexity, Bellairs Institute (Barbados), March 2008.
SAGE Days 7, IPAM (Los Angeles), February 2008 (no talk).
SAGE Days 6, Heilbronn Institute (Bristol), November 2007 (no talk).
p-adic aspects of differential equations: Crystals, mirror symmetry, modular forms, Centre Interfacultaire Bernoulli (Lausanne), November 2007.
Arithmetic, Geometry, and Coding Theory (AGCT-11), CIRM (Luminy), November 2007.
Computational arithmetic geometry (SAGE Days 5), Clay Institute (Cambridge, MA), September-October 2007 (organizer plus talk).
Of ramification and vanishing cycles, Tokyo, September 2007 (no talk).
L-functions and modular forms, AIM (Palo Alto), July-August 2007 (organizer; no talk).
Communicating mathematics, Duluth, July 2007.
Journées Arithmétiques, Edinburgh, July 2007 (plenary lecture).
p-adic methods in arithmetic geometry and its applications, Tokyo, June 2007.
p-adic aspects of arithmetic geometry, Tambara Institute (Japan), June 2007.
AMS-SMM Joint Meeting, Zacatecas (Mexico), May 2007 (invited address).
p-adic methods and rational points, Rényi Institute, Budapest, May 2007.
p-adic geometry, Arizona Winter School, March 2007 (series of 4 lectures plus student project).
Explicit methods for rational points on curves, Banff, February 2007.
Modularity of Galois representations, MSRI, November 2006 (no talk).
Computational challenges arising in algorithmic number theory and cryptography, Fields Institute (Toronto), November 2006.
Number theory and cryptography: open problems, IPAM (Los Angeles), October 2006.
SAGE Days 2, Seattle, October 2006 (no talk).
Maine-Québec Number Theory Conference, U. Laval, October 2006.
Hodge theory, Venice, June 2006.
Rings of low rank, Leiden, June 2006.
Symposion of SFB "Geometrische Strukturen in der Mathematik", Münster, June 2006.
AMS session on computational arithmetic geometry, San Francisco, April 2006.
AMS session on arithmetic geometry and modular forms, Durham (NH), April 2006.
p-adic representations, modularity, and beyond, AIM (Palo Alto), February 2006 (organizer plus talk).
SAGE Days 1, San Diego, February 2006 (no talk).
Arithmetic, geometry, and coding theory, CIRM (Luminy), September 2005.
p-adic representations, CRM (Montreal), September 2005 (no talk).
Arithmetic geometry (component of AMS Summer Institute on algebraic geometry), August 2005 (session organizer plus talk).
Explicit methods in number theory, Oberwolfach, July 2005.
Algebraic number theory, Oberwolfach, June 2005.
Budapest Semesters in Mathematics reunion, Budapest, June 2005 (program committee plus talk).
CMS session on automatic sequences, Waterloo, June 2005.
p-adic cohomology and cryptography, Rennes, June 2005.
Arithmetic geometry, Florida, February-March 2005.
p-adic differential equations, Münster, February 2005.
AMS session on D-modules, Atlanta, January 2005.
Workshop on F-isocrystals and rigid cohomology, December 2004 (Padova, no talk) and June 2005 (Rennes).
Arithmetic Geometry (two talks), SUNY-Buffalo, September 2004.
Canadian Number Theory Association (CNTA VIII), Toronto, June 2004.
Algorithmic Number Theory Symposium (ANTS VI), Burlington, June 2004.
3rd Duke Mathematical Journal Conference, Duke, April 2004.
Arithmetic Geometry, Tokyo, February 2004.
AMS session on arithmetical algebraic geometry, Phoenix, January 2004.
L-functions and cohomology: computational perspectives (two talks), CRM-CICMA workshop, Far Hills (Québec), January 2004.
Geometric methods in algebra and number theory, Miami, December 2003.
Arithmetic Algebraic Geometry, Max-Planck-Institut (Bonn), September 2003.
Current trends in arithmetic geometry and number theory, Banff, August 2003.
Semaine Cohomologique, Rennes, June 2003.
AMS session on geometry and arithmetic over finite fields, San Francisco, May 2003.
Future directions in algorithmic number theory, AIM (Palo Alto), March 2003.
Computational Aspects of Algebraic Curves and Cryptography, Florida, March 2003.
AMS session on computational algebraic and analytic geometry for low-dimensional varieties, Baltimore, January 2003.
Elliptic Curve Cryptography, Essen, September 2002.
Ramification in Geometry and Arithmetic, Paris (no talk), September 2002.
Symposion of SFB "Geometrische Strukturen in der Mathematik", Münster, July 2002.
AMS session on arithmetic geometry, Pisa, June 2002.
Midwest Arithmetic Geometry in Cryptography, Illinois (Champaign-Urbana), November 2001.
Dwork Trimester component on Rigid Geometry and Isocrystals, Padova, June 2001.
AMS session on computational algebraic geometry for curves and surfaces, San Antonio, January 1999.
AMS session on undergraduate research, San Francisco, January 1995.

Invited talks in seminars/colloquia

Number theory seminar, Caltech, two occasions (last: October 2017).
Number theory seminar, Hawaii, September 2017.
Number theory seminar, University of British Columbia, May 2017.
Colloquium, UC Santa Cruz, May 2017.
Number theory seminar (four-lecture series), University of British Columbia, February 2017.
Algebra/number theory seminar, Louisiana State, September 2016.
Number theory seminar, UCLA, May 2016.
Number theory seminar, UC Irvine, April 2016.
Colloquium, Rice, March 2016.
Geometric Langlands seminar, Chicago, February-March 2016 (two lectures).
Colloquium, Purdue, February 2016.
Colloquium, Connecticut, October 2015.
Colloquium, Brown, October 2015.
Number theory seminar, Harvard, several occasions (last: October 2015).
Colloquium, Michigan, September 2015.
Number theory seminar, Wisconsin, September 2015.
Number theory seminar, Regensburg, July 2015.
Colloquium, EPFL (Lausanne), March 2015.
Colloquium, Kings College, London, March 2015.
Distinguished lecture in mathematics, Nottingham, March 2015.
Number theory seminar, Imperial College, March 2015.
Colloquium, Cambridge, November 2014.
Research seminar, MSRI, November 2014.
Number theory seminar, Montpellier, November 2014.
BC/MIT number theory seminar, Boston College, September 2014.
Number theory seminar, Connecticut, September 2014.
Number theory seminar, UCLA, two occasions (last: April 2014).
Colloquium, Texas, April 2014.
Number theory/algebraic geometry joint seminar, Stanford, March 2014.
Number theory seminar, Strasbourg, October 2013.
Cryptography seminar, Rennes, two occasions (last: September 2013).
Number theory seminar, UC Irvine, two occasions (last: May 2013).
Number theory seminar, Yale, May 2013.
Number theory seminar, Beijing Univ., December 2012.
Number theory seminar, Maryland, two occasions (last: December 2012).
Seminar in MSRI thematic program on cluster algebras, November 2012.
Number theory seminar, UC Santa Cruz, two occasions (last: October 2012).
Algebra seminar, Colorado State, April 2012.
Number theory seminar, UC Berkeley, several occasions (last: April 2012).
Algebraic geometry seminar, Stanford, April 2012.
Magma seminar, Sydney, December 2011.
Colloquium, NU Singapore, December 2011.
Colloquium, UCLA, October 2011.
Colloquium, CSU Dominguez Hills, October 2011.
Number theory seminar, Univ. of Chicago, October 2011.
Berkeley-Stanford algebraic geometry colloquium, Berkeley, October 2010.
Algebraic geometry seminar, Harvard-MIT, March 2010.
Number theory seminar, Melbourne, January 2010.
Computational number theory seminar, Sydney, January 2010.
Number theory seminar, Princeton, November 2009.
Algebraic geometry seminar, Michigan, November 2009.
Colloquium, UC Berkeley, March 2009.
Colloquium, Emory (Atlanta), February 2009.
Colloquium, UC San Diego, February 2009.
Number theory seminar, Northwestern, February 2009.
Colloquium, McGill, November 2008.
Algebra seminar, Saskatchewan, November 2008.
Colloquium, TIFR (Mumbai), July 2008.
Two lectures in special semester on arithmetic geometry, TIFR (Mumbai), July 2008.
Columbia-NYU-CUNY joint number theory seminar, May 2008.
MIT combinatorics seminar, two occasions (last: April 2008).
Colby-Bates-Bowdoin algebra-topology colloquium, April 2008.
Columbia-NYU-Princeton joint algebraic geometry seminar, February 2008.
Colloquium, UCLA, February 2008.
Number theory/algebraic geometry seminar, Paris-Sud, December 2007.
Number theory seminar, Nagoya, May 2007.
Special colloquium, Brown, January 2007.
MIT lunch seminar for graduate students, October 2006.
Quebec-Vermont Number Theory Seminar, Montréal, two occasions (last: September 2006).
Number theory seminar, Columbia-CUNY-NYU, December 2005.
Special seminar, Brown, November 2005.
Algebraic geometry seminar, Stanford, two occasions (last: May 2005).
Fellowship of the Ring seminar, Brandeis, two occasions (last: April 2005).
Algebraic geometry seminar, Illinois (Champaign-Urbana), April 2005.
Algebraic geometry seminar, Ohio State, November 2004.
Algebra seminar, Boston U., November 2004.
Five College Number Theory Seminar, Amherst (MA), November 2004.
Colloquium, US Naval Academy (Annapolis), September 2004.
Number theory seminar, Brown, March 2004.
Algebraic geometry seminar, Hiroshima, January 2004.
Number theory seminar, Padova, November 2003.
Number theory seminar, ETH (Zürich), November 2003.
Members seminar, Institute for Advanced Study (Princeton), October 2003.
Algebra seminar, Pennsylvania, October 2003.
Number theory seminar, Paris 13, June 2003.
Seminar, Microsoft Research, May 2003.
Special lecture series, Arizona, May 2003.
Algebraic geometry/number theory seminar, Stanford, April 2003.
Number theory/algebraic geometry seminar, Utah, two occasions (last: April 2003).
Colloquium, Utah, April 2003.
Special colloquium, Minnesota, January 2003.
Number theory seminar, Michigan, January 2003.
Special colloquium, Illinois (Chicago), January 2003.
Special colloquium, Toronto, January 2003.
Number theory seminar, Illinois (Chicago), November 2002.
Number theory seminar, Texas (Austin), November 2002.
Number theory seminar, Rome 2, June 2002.
Number theory seminar, Rennes, May 2002.
Colloquium, George Washington, March 2002.
Number theory seminar, Penn State, March 2002.
Algebraic geometry seminar, Princeton, March 2002.
Number theory seminar, Columbia, March 2002.
Algebraic geometry seminar, U. of Chicago, December 2001.
Number theory seminar, Illinois (Champaign-Urbana), November 2001.
Colloquium, Southern California, October 2000.

Other talks and presentations

Includes talks for precollege, undergraduate, or general audiences, as well as panel discussions.

Undergraduate pizza seminar, UC Irvine, April 2017.
Undergraduate and graduate student colloquia, Louisiana State, September 2016.
SUMS conference, Brown, March 2016.
University of San Francisco colloquium, September 2014.
Project NExT panel on Math-related Service Activities and Outreach, January 2014.
Bay Area Math Adventures, January 2012.
San Diego Math Circle, October 2011.
MIT SPUR (Summer Program in Undergraduate Research), July 2007.
University of Connecticut undergraduate math club, October 2006.
MIT and Underground Railway Theater, panel discussion on Ira Hauptman's play Partition, May 2006.
MIT Math Department IAP lecture series, January 2006.
Colby College colloquium, October 2005.
Bowdoin College undergraduate math lunch, October 2005.
PROMYS, July 2005.
MIT Science and Engineering Program for Teachers, June 2005.
The Math Circle (Boston), October 2004.
MIT Undergraduate Math Association, September 2004.
Canada/USA Mathcamp, several occasions (last: summer 2004).
Math Olympiad Summer Program, numerous occasions (last: summer 2004).
Clay Research Academy, Clay Mathematics Institute, March 2004.
Berkeley Math Circle, numerous occasions (last: spring 2003).