(1) Canonical actions on the Cuntz alegbra of infinite order: Univerity of California at Los Angeles (UCLA); February 1991.

(2) Indice di Jones, quadrati commutativi ed il problema della classificazione dei sottofattori: Universita di Roma "La Sapienza"; June 1992.

(3) Random walks on discrete groups: a theorem of Varopoulos: talk at the summer course on “Harmonic Analysis” in Cortona (Italy); July 1992.

(4) Local Observables and Particle Statistics (after Doplicher–Haag–Roberts): series of seminars at the UCLA, Winter Quarter 1992-93.

(5) Approximately inner and centrally free commuting squares of type II 1 factors and their classification: UCLA; May 1994.

(6) Le theoreme spectral pour les operateurs auto-adjoints: Seminaire Mathematique de la Suisse Romande sur la cohomologie des groupes discrets, Lausanne; February 1995.

(7) Discrete potential theory, combinatorial Laplacian and random walks: Workshop “Cohomology of groups”, Chateau d’ Oex (Switzerland); March 1995.

(8) Operatori di Markov su gruppi iperbolici: Convegno Nazionale di Analisi Armonica, Alghero (Italy); June 1995.

(9) Sur un theoreme de Varopoulos: Universite de Geneve; October 1995.

(10) Moyennabilite et croissance des groupes a un seul relateur: Universite de Geneve; February 1996.

(11) Amenabilit`a e crescita di gruppi ad un solo relatore I, II: Harmonic Analysis Seminar,  Universita di Roma "La Sapienza"; March 1996.

(12) Metodi analitici nella teoria dei gruppi: hopfianita' dei gruppi liberi: Harmonic Analysis Seminar,Universita di Roma "La Sapienza"; March 1996.

(13) Aspetti analitici nella teoria combinatorica dei gruppi: Convegno Nazionale di Analisi Armonica, Grado; May 1996.

(14) Amenability and growth of one–relator groups: Euroconference in Algebra and Discrete Mathematics: “Group Theory: from Finite to Infinite”; Castelvecchio Pascoli (LU); July 1996.

(15) Amenable groups and cellular automata: Seminar on Dynamical Systems (D.V. Anosov), Moscow State University; December 1996.

(16) Grafi amenabili e grafi paradossali: Harmonic Analysis Seminar, Universita di Roma "La Sapienza"; March 1997.

(17) Gruppi amenabili ed automi cellulari: Convegno Nazionale di Analisi Armonica, S. Margherita Ligure; March 1997.

(18) Graphes moyennables et graphes paradoxales: Universite de Geneve; March 1997.

(19) Amenability and growth of one–relator groups: Workshop on General Combinatorial Group Theory, CRM (Montreal); April 1997.

(20) Growth series and random walks on some hyperbolic graphs: Conference “Random Walks and Discrete Potential Theory”, Cortona; June 1997.

(21) Moyennabilit´e et paradoxes: Colloquium at the Math. Dept. Universite de Neuchatel; October 1997.

(22) Amenability and paradoxes: Universita degli Studi di Milano; January 1998.

(23) Groupes moyennables et automates cellulaires: Workshop “Geometrie et Combinatoire des groupes”, Geneva; January 1998.

(24) Around Amenability: Convegno Nazionale di Analisi Armonica, Ponza; June 1998.

(25) Amenabilit`a e paradossi: Universit`a degli Studi di Ancona; July 8, 1998.

(26) Paradoxical decompositions of free Burnside groups: International Conference in Mathematics on the 90th anniversary of L.S. Pontryagin,  Moscow; August 1998.

(27) Teoria ergodica e teoria combinatorica dei numeri: series of seminars held in collaboration with Fabio Scarabotti at the Universita di Roma “La Sapienza”; January - June 1999.

(28) Theorie de Ramsey ergodique: Universite de Geneve; May 1999.

(29) Un invito alla teoreia di Ramsey ergodica: Convegno Nazionale di Analisi Armonica, Aosta; June 1999.

(30) Garden of Eden Theorems for Amenable subshifts: Hebrew University, Jerusalem;  April 2000.

(31) Il gruppo di Grigorchuk di crescita intermedia: Convegno Nazionale di Analisi Armonica, Como; June 2000.

(32) Paradoxical decompositions of free Burnside groups: International Conference ”Geometric & Combinatorial Group Theory”, Technion, Haifa; June 2000.

(33) Inner Amenability of Richard Thompson’s group F: TU Graz; December 2000.

(34) Croissance des languages libres du contexte:  Universite de Neuchatel; May 2001.

(36) Growth tightness of context free languages: Universite de Geneve;  May 2001.

(37) Linguaggi context-free e loro crescita: Convegno Nazionale di Analisi Armonica, Piano di Sorrento; May 2001.

(38) Growth tightness of context free languages: “Random Walks and Geometry” at the ESI Vienna; June 2001.

(39) Entropy of graphs, formal languages and symbolic dynamical systems. Royal Institute of Technology (KTH), Stockholm; December 2001.

(40) Random walks e amenabilita: il teorema di Tarski: “Probabilistic models and disordered systems”: Roma February 4-7, 2002.

(41) Metodi di random walks in teoria dei gruppi: amenabilita e hopfianita: Seminario di Probabilita di Roma I. Roma;  February 2002.

(42) Introduzione agli espansori e ai grafi di Ramanujan: Istituto Nazionale di Alta Matematica (INdAM), Roma; February 2002.

(43) La proprieta (T) di Kazhdan I & II: Istituto Nazionale di Alta Matematica (INdAM),  Roma; May 2002.

(44) Entropie de graphes et applications: Universite de Neuchatel; May 2002.

(45) Espansori anisotropi: il teorema di Alon-Boppana: “Convegno Nazionale di Analisi Armonica” Isole Tremiti;  June 2002.

(46) Entropy of symbolic dynamical systems and of formal languages: International workshop on “Semigroups, Automata, and Formal Languages”.  Crema; June 2002.

(47) Distribuzioni e misure sulla frontiera dell’albero: Istituto Nazionale di Alta Matematica  (INdAM),  Roma, Nov 6 2002.

(48) The Tarski number of free Burniside groups: UC San Diego; Jan 2003.

(49) Amenable groups, symbolic dinamical systems, formal languages and their entropy: Texas A & M University; Jan 2003.

(50) Amenable groups: Tarski’s theorem, Rutgers University; Feb 2003.

(51) Amenable groups, symbolic dinamical systems, formal languages and their entropy, Princeton University; Feb 2003.

(52) La teoria di Kaloujnine e i codici di Reed-Muller. “Convegno Nazionale di AnalisiArmonica”, Padova; May 2003.

(53) Amenable groups and paradoxical decompositions: a theorem of Tarski. University of Haifa; June 2003.

(54) Amenable groups and paradoxical decompositions: a theorem of Tarski. Al Quds University, Abu Dis (Palestine Authority); June 2003.

(55) Amenable groups and paradoxical decompositions: a theorem of Tarski. “Geometric and Group Theory Methods in Algebraic Structures”, Batumi (Georgia); Sept. 2003.

(56) Amenablility for Banach Algebras, C^∗−algebras and von Neumann algebras. Series of talks at UCSD; Feb 2004.

(57) Generalized Kaloujnine groups, uniseriality and the height of automorphisms. Universite de Geneve; March 2004.

(58) Gruppi a crescita lineare. “Convegno Nazionale di Analisi Armonica”. Sestri Levante, March 2004.

(59) Finite Gelfand pairs: (new) examples and applications. Texas A & M University; Sept 2004.

(60) Copppie di Gelfand finite: nuovi esempi ed applicazioni. Universita di Roma “La Sapienza”; Sept 2004.

(61) Couples de Guelfand finis : (nouveaux) examples et applications. Conference on the occasion of Pierre de la Harpe’s 60th birthday, Geneva; October 2004.

(62) Amenability and paradoxical decompositions: Tarski’s theorem. Texas A & M University;  Oct 2004.

(63) Amenability and paradoxical decompositions: Tarski’s theorem. University of Iowa; Oct 2004.

(64) Finite Gelfand pairs: (new) examples and application. University of Iowa; Nov 2004.

(65) Cellular Automata, subshifts and amenable groups. Fall Workshop 1: Asymptotic group invariants and their applications. Texas A & M University; Nov 2004.

(66) Automata, linear languages and their growth. Fall Workshop 2: Asymptotic group invariants and their applications. Texas A & M University; Dec 2004.

(67) On a graph of intermediate growth. Texas A & M University,  Jan 2005.

(68) Copppie di Gelfand finite: nuovi esempi ed applicazioni. “Convegno Nazionale di Analisi Armonica”. Padova; April 2005.

(69) Cellular automata, amenability and group rings. 5th International Algebraic Conference, Odessa (Ucraina); July 20-27, 2005.

(70) Il teorema dell’alternativa di Tits. Universita di Roma “La Sapienza”; Feb 2006.

(71) Trees, wreath products and finite Gelfand pairs, ESI Vienna Workshop in “Discrete Probability”; March 2006.

(72) Gruppi sofici e surgiuntivit`a di alcuni sistemi dinamici “Convegno Nazionale di Analisi Armonica”. Cortona; May 2006.

(73) Linear cellular automata, sofic groups and stable finiteness of group rings, Algebra Colloquium,  UCSD; November 2006.

(74) Linear cellular automata, sofic groups and stable finiteness of group rings, Functional Analysis Colloquium, UCLA; November 2006.

(75) Growth of finitely generated groups and Gromov’s theorem for groups of polynomial growth : I, II & III, Special Student Seminar (Minicourse), Rice University,Houston; November 16-17, 2006.

(76) Linear cellular automata, sofic groups and stable finiteness of group rings, Special Colloquium, Rice University, Houston; November 2006.

(77) Minimal ergodic topological action do not determine the measurable orbit equivalence class, “Special day on Groups and Dynamics” Fall Workshop, Texas A & M University; November 2006.

(78) Minimal ergodic topological action do not determine the measurable orbit equivalence class, Convegno Nazionale di Analisi Armonica, Caramanico Terme (PS), May 2007.

(79) Minimal ergodic topological action do not determine the measurable orbit equivalence class, Workshop “Groups and their actions”, Banach Center Bedlewo (Poland); July 2007.

(80) Minimal ergodic topological action do not determine the measurable orbit equivalence class, “6th International algebraic conference in Ukraine”, Kamyanets-Podilsky; July 2007.

(81) Finite Gelfand pairs: new examples and applications, ”The First Petra International Conference in Mathematics”, Al-Hussein Bin Talal University, Ma’an (Jordan); October 2007.

(82) Automates cellulaires et groupes : groupes moyennables et groupes sophiques, Universite de Paris VI (Chevaleret); November 2007.

(83) Expanisive actions on uniform spaces and surjunctive maps, Convegno Nazionale di Analisi Armonica, Perugia; May 2008.

(84) Espaces uniformes, automates cellulaires et groupes surjonctifs, “Analyse, geometrie et dynamique sur les groupes”, Neuchatel; June 2008.

(85) Uniform spaces, cellular automata and surjunctive groups, International conference “Differential Equations and Topology” dedicated to the Centennial of L.S. Pontryagin”, Moscow; June 2008.

(86) Uniform spaces, cellular automata and surjunctive groups, “ESI Workshop on Structural Probability”, Schoredinger Institute, Vienna; November 2008.

(87) Cellular automata and groups: dynamical aspects of infinite groups, TU Graz, October 2009.

(88) Automates cellulaires et groupes: aspects dynamiques des groupes infinis, Universite de Geneve; November 2009.

(89) Cellular automata and groups: dynamical aspects of infinite groups, TIFR Mumbai (India); December 2009.

(90) Automata in group theory and in the theory of formal languages (Minicourse), TIFR Mumbai (India); December 2009.

(91) Cellular automata and groups: dynamical aspects of infinite groups, Ramanujan Insitute of Mathematics, Madras/Chennai (India); December 2009.

(92) On the Okounkov-Vershik approach to the representation theory of the symmetric groups (Minicourse), Kyushu University, Fukuoka (Japan); February 2010.

(93) Cellular automata and groups: dynamical aspects of infinite groups, Kyushu University, Fukuoka (Japan); February 2010.

(94) Automi cellulari e gruppi: aspetti dinamici dei gruppi infiniti Universita di Salerno; February 2010.

(95) On the Okounkov-Vershik approach to the representation theory of the symmetric groups, XXX Convegno Nazionale di Analisi Armonica, Gargnano (BS); June 2010.

(96) Algebraic cellular automata, TU Graz, Austria; September 2010.

(97) Minimal topological actions do not determine the measurable orbit equivalence class, First Joint Meeting American Mathematical Society - Sociedad de Matem´atica de Chile, Pucon (Chile); December 2010

(98) On surjunctive groups, Rice University, Houston; March 2011.

(99) On surjunctive groups, Texas A & M University, College Station; March 2011.

(100) Symbolic Dynamics and One-dimensional Cellular Automata (Minicourse), Chebyshev Laboratory, San Pietroburgo (Russia); April 2011.

(101) Symbolic Dynamics and Cellular Automata on Groups, Chebyshev Lab Colloquium, Chebyshev Laboratory, San Pietroburgo (Russia); April 2011.

(102) Symbolic dynamics and sofic groups, Oberwolfach Seminar; May 12011.

(103) Surjunctivity of cellular automata and sofic groups, XXXI Convegno Nazionale di Analisi Armonica, INdAM Roma; June, 2011.

(104) Surjunctivity of cellular automata and sofic groups, UCLA, Los Angeles; August 2011.

(105) On surjunctivity I & II, Seminaire LaWiNe (Lausanne-Wien-Neuchatel, Mathematical Seminar on Sofic Groups); December 2012.

(106) Groupes et languages : le probleme des mots, ENS Lyon; February 2013.

(107) Automates cellulaires et groupes, Seminaire Tripode, Institut Camille Jordan (Lyon 1); February 2013.

(108) Groupes et languages : le probl`eme des mots, S´eminaire Quantique, IRMA, Universite de Strasbourg; March 2013.

(109) Cellular automata, amenable groups, surjunctivity, and sofic groups, University of Warwick; May 2013.

(110) The Garden of Eden theorem for cellular automata over amenable groups (MINI-COUSE), ICTP-SISSA-Moscow School on Geometry and Dynamics, Trieste, June 2013.

(111) Cellular automata and groups, Kyoto University (Japan); August 2013.

(112) Advanced Mackey theory for finite groups, “International Workshop on Noncommutative Analysis And Its Future Prospects” Hokkaido University, Sapporo, (Japan); August 2013.

(113) Cellular automata and groups, University of Tokyo (Japan); August 2013.

(114) Cellular automata on rooted trees, IHP Paris; February 2014.

(115) Introduction to sofic groups, UCSD, San Diego; August 2014.

(116) Introduction to linearly sofic groups, UCSD, San Diego; August 2014.

(117) Rabin automata and cellular automata on regular rooted trees, UCSD, San Diego; August  2014.

(118) Aspetti algebrici, analitici e logico-informatici della teoria degli automi cellulari sui gruppi. Universita di Verona; September 2014.

(119) On soficity and surjunctivity for monoids, IMAR Bucharest, Romania; October 2014.

(120) Multipass automata and group word problems, TU Graz (Austria); October 2014.

(121) Sur la soficite et la surjonctivite des monoides, Universite de Geneve; October 2014.

(122) Cellular automata and groups: Garden of Eden Theorem, Amenable Groups, Surjunctivity and Sofic Groups, MINICOURSE at the ”Workshop on Symbolic Dynamics on finitely presented Groups” CMM Santiago de Chile; December 2014.

(123) A Garden of Eden Theorem for hyperbolic dynamical systems, XXXV Convegno Nazionale di Analisi Armonica, Matera; May 2015.

(124) On soficity and surjunctivity for monoids, AMS-EMS-SPM International Meeting, Porto (Portugal); June 2015.

(125) Expansive actions of countable amenable groups with the Myhill property, Texas A & M University; November 2015.

(126) Cellular Automata and Groups, University of South Florida, November 2015.

(127) MINICOURSE: Automata and groups, TU Graz; January-February 2016.

(128) A Garden of Eden Theorem for Anosov diffeomorphisms on tori, TU Graz; January 2016.

(129) The Garden of Eden Theorem: old and new, IMAR Monthly Lecture, IMAR Bucharest; September 2016.

(130) The Garden of Eden Theorem: old and new, Kopenhagen University; October 2016.

(131) Multiplicity-free induced representations, International Workshop on Algebraic Combinatorics, Hefei University (China);  October 2016.

(132) Product of (finite) graphs and expanders, Shanghai Jao Tong University (China), November 2016.

(133) The Garden of Eden Theorem: old and new, Shanghai Jao Tong University (China), November 2016.

(134) Expansive actions of amenable groups and homoclinic points, University of Vienna, November 2016.

(135) MINICOURSE: The Garden of Eden Theorem: from symbolic dynamics to Anosov dffeomorphisms and to algebraic dynamical systems, UFSC, Florianopolis (Brazil);  March 2017

(136) Surjunctivity of dynamical systems: old and new, International conference “Groups and computation: interactions between geometric group theory, computability, and computer science”, Stevens Institute of Technology, Hoboken NJ, June 2017.

(137) The Garden of Eden theorem and surjunctivity: old and new. I and II, Chinese Academy of Sciences, Beijing (China); September 2017.

(138) Minicourse: Amenability, growth, and dynamical systems. Shanghai Jao Tong University, Shanghai (China); September 2017.

(139) A Garden of Eden Theorem for Harmonic Models, University of Illinois at Urbana-Champaign; January 2018.

(140) The Garden of Eden Theorem: old and new, MATH COLLOQUIUM, University of Illinois at Urbana-Champaign; January 2018.

(141) The Garden of Eden Theorem and Dynamical Systems, EMS Conference “Emil Artin International Conference”, Yerevan (Armenia); May 2018.

(142) The Garden of Eden for algebraic dynamical systems, the Graduate Center (CUNY), New York; September 2018.

(143) The Garden of Eden for algebraic dynamical systems, “UMI-SIMAI-PTM Joint meeting” (session: dynamical systems and ergodic theory), Wroclaw (Poland); September 2018.

(144) Surjunctivity for algebraic dynamical systems,“UMI-SIMAI-PTM Joint meeting” (session: group theory), Wroclaw (Poland); September 2018.

(145) Minicourse: Amenability of groups. Thematic Research Program: Operator Algebras, Groups and Applications to Quantum Information, Universidad Carlos III de Madrid; March 2019.

(146) Garden of Eden theorems, Workshop “Groups and Group Rings” The Modern Algebra and its Applications Lab, St. Petersburg (Russia); June 2019.

(147) The Garden of Eden Theorem: from cellular automata to algebraic dynamical systems,  Plenary Talk at “AUTOMATA 19: the 25th International Workshop on Cellular Automata and Discrete Complex Systems”, Guadalajara (Mexico); June 2019.

(148) Minicourse: Topics in representation theory. The International Conference and PhD-Master Summer School on Groups and Graphs, Designs and Dynamics. Yichang (China), August 2019.

(149) The Garden of Eden Theorem: from cellular automata to algebraic dynamical systems, Shanghai Jao Tong University, Shanghai; August 2019.

(150) Gelfand pairs and multiplicity-free induced representations of finite groups, Texas A& M University, November 2019.

(151) Expansive actions with specification of sofic groups, strong topological Markov property, and surjunctivity, University of Illinois a Urbana Champaign; February 2020.

(152) Linear subshifts and dynamics of linear cellular automata (on-line), Shanghai Jao Tong University, China; November 2020.

(153) Endomorphisms of linear subshifts (on-line), Expaning Dynamics VII, Creative On-line Ventures in Dynamics; December 2020.

(154) Linear cellular automata, linear subshifts, and group rings (on-line), New York Group Theory Seminar; March 2021.

(155) Sofic entropy and surjunctivity of dynamical systems, Universite de Geneve; November 2021.

(156) Zapiska do Teoremi Kaluzhnina y Krasnera (A note on the Kaloujnine-Krasner theorem); seminar “Ivan Fedorovych Grygorchuk’s 95-th Anniversary” (online) February 2022.

(157) From (finite) Gelfand pairs to (finite) multiplicity-free triples; seminar “Geometry and Symmetry” at Nottingham University, (online; February 2022.

(158) Entropy tightness of irreducible sofic subshifts; Kolloquium aus Anlass der Emeritierung von Wolfgang Woess, TU Graz; October 2022.

(159) Sofic entropy and surjunctivity of dynamical systems; University of Vienna; October 2022.

(160) Amenability, Entropy, and the Garden of Eden Theorem, “Groups of dynamical origin, automata and spectra” SwissMap Station Les Diablerets (CH), March 2023.

(161) An Invitation to Symbolic Dynamics on Groups, “Differential Algebra and Related Topics XI ”Queen Mary University, London; June 2023.

(162) Linear Symbolic Dynamics and Group Rings, “Teoria dei Gruppi a Paestum: due giornate speciali” Paestum, July 2023.

(163) First-order model theory, surjunctivity, and Kaplansky’s stable finiteness conjecture, Universite de Geneve; January 2024.

(164) First-order model theory, surjunctivity, and Kaplansky’s stable finiteness conjecture, GAGTA 2024, CIRM (Marseille-Luminy); February 2024.

(165) First-order model theory, surjunctivity, and Kaplansky’s stable finiteness conjecture (on-line), Universitad de Guadalajara (Mexico); March 2024.