October 25 – October 28 2023, Colloquium dedicated to Eberhard Becker on the occasion of his 80th birthday, Dortmund (Germany).
May 28-June 3 2023, Model theory of valued fields, CIRM, Luminy.
March 12-18 2023, invited to « Real Algebraic Geometry with a View toward Koopman Operator
Methods », Mathematisches Forschungsinstitut, Oberwolfach, (Germany).
October 23-28 and October 30 – November 4 2022, « Real Algebraic Geometry » and « Real
Aspects of Geometry », CIRM – Luminy.
June 19-25 2022, invited « Model Theory and Applications 2022 », Cetraro meeting (Italie).
June 14-25 2021, Summer school « Symplectic, real, and tropical aspects of
enumerative geometry » and Conference « Facets of real algebraic geometry », Le Croisic et
Nantes.
March 1-7 2020, invited to « Real Algebraic Geometry with a View Toward Hyperbolic »,
Mathematisches Forschungsinstitut, Oberwolfach, (Germany)
November 3-9 2019, participation to the final conference « Conference on Global Approach to
the Gender Gap in Mathematical, Computing and Natural Sciences: How to Measure It, How to
Reduce It? » ; ICTP Trieste (Italy)
March 29th – April 7th 2019 : invited speaker, On the number of connected components of
smooth projective non empty real varieties., Arctic Applied Algebra, Artic University, Tromso,
(Norway)
December 6-8 2018 : invited speaker, A Global Approach to the Gender Gap in Mathematical,
Computing, and Natural Sciences: How to Measure It, How to Reduce It? ; KWIM-Festtage”
Konstantz University (Germany)
November 23-29 2018 : invited speaker, From Orderings to Valuation Fans and Related Topics,
Algebra : celebrating Paulo Ribenboim’s ninetieth birthday.
https://www.ime.usp.br/~eventoribenboim/, University Sao Paulo, Sao Paulo, Brazil
January 7-13 2018 : Research School, Model Theory, Combinatorics and Valued Fields, CIRM,
Luminy.
December 1-3 2017 : Regional meeting of ICSU project « A Global Approach to the Gender Gap
in Mathematical and Natural Sciences: How to Measure It, How to Reduce It? », Le cap
(Afrique du Sud).
September 17-22 2017 : « Perspectives in Real Geometry », CIRM, Luminy.
August 20-26 2017 : « Sums of squares » University if Innsbruck (Autriche).
March 11-19 2017 : « Topics in Real Geometry », Graduate School of Mathematics, Nagoya
University (Japon).
March 5-10 2017 : « Real Algebraic Geometry with a view towards moment problems and optimization »,
Mathematisches Forschungsinstitut, Oberwolfach, (Germany)
August 30-31 2016 : « Marshall’s problem and some further developments », invited speaker
nineteenth colloquiumfest held in honor of Murray Marshall, University of Saskatchewan,
Saskatoon, (Canada).
October 11-17 2015 : « Ordered Algebraic Structures and related Topics », CIRM, Luminy.
June 17-20 2014 : « Olga Taussky-Todd, sums of squares and Hilbert’s 17th problem », invited
speaker, Konstantz University (Germany)
April 6-12 2014 : « Real Algebraic Geometry With A View Toward Systems Control and Free
Positivity », Mathematisches Forschungsinstitut, Oberwolfach, (Germany)
January 5-18 2014 : Invited Professor : « R- places and related topics », Doctorate course in
summer doctoral school. Universidad de Concepcion (Chile).
January 8-9 2014 : « Hilbert’s 17th problem : an old problem with new developments », invited
talk for the closure of mini-congreso, Universidad del Bio Bio, Concepcion (Chile)
July 17-20 2013 : Model Theory and applications to Geometry, CMAF Universidade de Lisboa ,
Lisbonne (Portugal).
July 15-20 2012 : “On Valuation Fans and Related Topics”, Invited Speaker in the XXII
Brazilian Algebra Meeting ; Salvador de Bahia (Brazil).
June 15- 19 2012 : invited to give seminar talks (Algebraic geometry and model theory
seminars) in Unviversity Konstantz (Allemagne)
August 21-28 2011 : Algebra, Combinatorics and Model Theory, Koc University, Istanbul,
Turquie.
July 23-29 2011 : « On R-places and related topics », Invited Speaker, Second international
conference and workshop on Valuations (Universités de Valladolid et de Madrid), El Escorial,
Espagne.
December 11-23 2010 : Conference “On valuation fans and some elementary theories” , special
session Algebra and Model Theory, of the first joint meeting AMS/SoMaChi, Pucon (Chili)
August 15-27 2010 : participation ICWNM and ICM 2010, Hyderabad (Inde).
September 30 – October 6 2009 : Positivity, Valuations and Quadratic Formes, Conference in
honor of Alexander Prestel, University of Konstanz, Germany.
August 9-14 2009 : ESF-EMS-ERCOM Conference on Model Theory, The Banach Center,
Bedlewo, Poland.
February 15-21 2009 : Meeting on “Real Analytic and Nash Functions and Related Topics”, “On
the number of connected components of smooth real varieties” in memoriam Alberto Tognoli,
University of Pisa, Italy.
November 7-8 2008 : Conference in honor of Eberhard Becker, University of Dortmund,
Germany.
September 13-15 2008, Conference on The Model Theory of Fields. University of Freiburg,
Germany.
August 4-18 2008 « On the number of connected components of smooth real varieties”,
Conference in honor of J.-J. Risler : “Around Hilbert’s 16th problem”, and Escola de Algebra,
IMPA, Rio de Janeiro, Brazil.
May 26 – June 02 2008, « Real Holomorphy Rings and the Complete Real Spectrum », 5th Linear
Algebra Workshop, University of Ljublijana, Kranjska Gora, Slovenia.
January 14-21 2008, “From Orderings to Valuation Fans” , Colloquium talk and research stay
at University of Hawaii at Manoa, USA.
January 8-14 2008, “From Artin Schreier to Valuation Fans”, Colloquium talk, and Real
Holomorphy Rings and the Complete Real Spectrum”, Seminar talk, University of Saskatchewan,
Canada.
April 24-30 2007, “On Real Holomorphy Rings of Rings”, invited speaker in Conference on
Oredered Rings, Louisiana State University, Baton Rouge, USA (Honoring Melvin Henriksen on
his 80th birthday).
November 25-27 2006, “On Theories of Closures of fields equipped with valuation fans”, invited
conference for the Model Theory of Fields, University of Freiburg, Germany.
October 7-14 2006, invitation to attend workshop « Positive Polynomials », Pacific Institute for
Mathematical Sciences, Banff, Canada.
October 5-6 2006, Invitation mini-conference “Topics in Real Algebraic Geometry”, University
of Saskatchewan, Saskatoon, Canada.
Avril 2-8 2006, »Reading Stengle », conference in worshop Sources for Real Geometry », held in
Cortona, Scuola Normale Superiore di Pisa, Italy.
March 20-26 2006, « On Valuation Fans », invited speaker in Workshop on »Valuation Theory
and its Application », in memoriam Otto Endler, University of Campinas, Brazil ;
March 17 2006, « Number of connected components of real algebraic varieties », Seminar of
Algebra, Universidad de Buenos Aires, Argentina.
September 4 – 9 2005, participation to the Annual RAAG meeting, University of Passau,
Germany.
March 28-April 7 2005, participation to Workshop, « An Introduction to recent applications of
Model Theory », Isaac Newton Institute, Cambridge, Great Britain.
November 7-16 2004, « Number of connected components and R-places », Seminar conference,
University of Saskatchewan, Saskatoon, Canada.
September 11-16 2004, « Nombre de composantes connexes d’une variété réelle », meeting on
Real Algebraic and Analytic Geometry, Université de Kenitra, Mehdia, Marocco.
July 14-27 2004, « Algebraic closures of a field equipped with a valuation fan », XVIII Escola de
Algebra, Campinas, Brazil.
June 21-27 2004, participation to the annual meeting RAAG »Real Algebraic and Analytic
Geometry », Universidades de Madrid et Santander, Salamanca, Spain.
April 12-16 2004 : « Number of connected components and R-places », Mathematical Sciences
Research Institute », Berkeley USA.
March 22-26 2004 : participant to the RAAG european network meeting « Singularity theory », in
honour of Stanislaw Lojasiewcz, Cracovie, Poland.
March 11-12 2004 : participant to « representation of semidefinite positive functions as sums of
squares and related topics ». University of Pisa, Italy.
January 8-20 2004 : invited conference « Towards a theory of R-places in spaces of orderings »,
XII° Simposio Latinoamericano de Logica matematica, Universidad de Costa Rica, San Jose,
Costa Rica.
November 11-18 2003 : invited conference » Higher level orderings and R-places » and work in
collaboration with professor Murray Marshall, University of Saskatchewan, Saskatoon, Canada.
October 22- 26 2003 : invited conference « From higher level orderings to R-places » , meeting
on Real Algebra, European Network RAAG, Universität Dortmund, Germany.
April 2003 : participant to the annual RAAG meeting, and stay centro di Ricerca Matematica
Ennio de Giorgi, Pisa, Italy.
Décember 2002 : participant to the « Quadratic Forms » meeting, Talca-Pucon, University of
Talca, Chile.
September 2002 : participant to the Conférence « Real Algebraic and Analytic geometry»,
european network RAAG, Kazimierz, Poland.
August 2002 : participation ICM 2002, Beijing, China.
May 2002 : invitation Euro-Conférence in «Model Theory and Applications », University of
Napoli, Ravello, Italy.
March 2002 : invited « Colloquiumfest on Valuation Theory », University of Saskatchewan,
Saskatoon, Canada.
November 2000 : invited conference, « From Hilbert’s 17th problem to valuation fans »,
University of Saskatchewan, Saskatoon, Canada.
July-August 1999 : invitation to the « International Conference and Workshop on Valuation
Theory », University of Saskatchewan, Saskatoon, Canada.
September 1998 : invitation by CIRM of Trento, « Real Algebraic and Analytic Geometry »,
Levico, Italy.
June 1998 : invited to the Workshop on »Model Theory, Algebra and Arithmetic », Mathematical
Sciences Research Institute, Université de Berkeley, U.S.A..
October 1997 : invited conference University of Trento, Italy.
September 1997 : invitation to HCM-Workshop « Spectral Spaces in Real and p-adic Geometry »,
University of Dortmund, Germany.
May 1997 : invited conference, Generalizations of Real-closed fields theory, University of Pise,
Italy.
September 1996 : « Real Algebraic and Analytic Geometry », University of Genève,
(Switzerland).
April 1996 : invited conference : special session of AMS meeting on « Real Algebraic Geometry
and Ordered Structures » Baton Rouge, Louisiane, U.S.A., and research stay (part of the « special
semester ») .
June 1995 : invited conference in « School on Model Theory and Real Algebraic Geometry », and
« Real Algebraic and Analytic Geometry », Universities of Madrid Santander, Segovia (Spain).
June 1994 : invited professor à l’Université de Dortmund, Germany, cooperation Program
Procope.
May 1994 : participant to the meeting « Real Algebraic and Analytic Geometry » organized by
University of Amsterdam in Soesterberg (Holland).
March 1993 : invited professor, University of Dortmund (Germany), cooperation Program
Procope.
September 1992 : invited conference, »Real Algebraic and Analytic Geometry », C.I.R.M.
Trento, Italy.
May 1992 : invitation to the meeting “Quadratische Formen“ Mathematisches
Forschungsinstitut Oberwolfach, Germany.
November 1991 : invited professor, Universität Dortmund, Germany, cooperation Program
Procope.
June 1989 : invited professor Universität Dortmund (R.F.A.), cooperation program Procope.
October 1988 : invited conference, « Real Algebraic and Analytic Geometry », C.I.R.M. Trento
(Italy).
August 1988 : participation to the « Logic Colloqium 88 », Padova, Italy.
July 1987 : conference in « Logic Colloquium 87 », Granada, Spain.
April 1987 : invited conference, meeting on « Reelle Algebraische Geometrie », Mathematisches
Forschungsinstitut Oberwolfach, R.F.A..
August 1986 : participation ICM 1986, University of Berkeley, U.S.A..
July 1986 : invitation to « Quadratic Forms and Real Algebraic Geometry », Oregon State
University, Corvallis, U.S.A..
July 1983 : invited and member of the organizing committee, A.M.S.- N.A.T.O. « Ordered Fields
and Real Algebraic Geometry », Boulder, Colorado, U.S.A..
January 1981 : invited conference, 87th A.M.Smeeting., special session on « Ordered Fields and
Real Algebraic Geometry », San Francisco, Californie, U.S.A..
August 1978 : participant ICM 1978, Helsinki, Finland.
Décember 1973 : invitation Bedford College de London, Great Britain.
June-July 1973 : invitation Open House, Queen’s University, Kingston, Ontario, Canada