- Kent State Functional Analysis Seminar, 1975, invited lecture.
- University of Western Ontario, London, Ontario, 1975, invited lectures.
- University of Oregon, Eugene, Oregon, invited to give a short talk during a special session on harmonic analysis, June 16-17, 1978.
- University of Aberdeen, Scotland, invited lecture on invariant means while visiting Professor Alan Paterson, Summer, 1979.
- Louisiana State University, Baton Rouge, invited colloquium, Summer 1980.
- Oklahoma State University, Stillwater, invited colloquium, Fall 1980.
- University of Wisconsin-Milwaukee, invited colloquium, Fall 1980.
- University of Arkansas, invited colloquium Winter 1981.
- University of Rochester, invited colloquium, Winter 1981.
- University of Missouri, Columbia, invited colloquium, Winter 1981.
- Syracuse University, invited colloquium, Winter 1981.
- AMS Meeting, Pittsburgh, invited lecture in special session on harmonic analysis, Spring 1981.
- Oklahoma State University, colloquium, Winter 1982.
- Northwestern University, invited special lecture, Spring 1982.
- University of Western Ontario, invited lecture at a special session on harmonic analysis on groups and semigroups, December 1984.
- Kansas State University, colloquium and special lecture, Spring 1986.
- Virginia Commonwealth University, colloquium, Spring 1986.
- Northwestern University, colloquium, Spring 1986.
- University of Alberta, colloquium, Summer 1987.
- University of Missouri, Columbia, colloquium, Spring 1988.
- First Conference on Almost Everywhere Convergence and Probability Theory, Spring 1988, OSU.
- Oklahoma State University, colloquium, Fall, 1988.
- Kansas State University, colloquium, Winter, 1989.
- University of Oklahoma, invited hour address, principal speaker: A. Lubotsky, Spring, 1989.
- Fifth Conference on Probability and Statistics, Vilnius, Lithuania, invited address, Summer, 1989.
- Leningrad Office of the Steklov Institute of Mathematics, Leningrad, invited address, Summer, 1989.
- Second Conference on Almost Everywhere Convergence and Probability Theory, Northwestern University, Fall 1989.
- Kansas State University, Regional AMS meeting, invited talk in a special session on harmonic analysis and probability theory, Spring, 1990.
- DePaul University/Northwestern University, special lectures, Winter, 1991.
- MAA, Student Chapter, OSU, invited short talk, on Phase Retrieval, Spring, 1991.
- Charles University, Prague, Czechoslovakia, invited talk, Fall, 1991.
- University of Wroclaw, Mathematical Institute, invited address, conference on operators on groups, Karpacz, Poland, Fall, 1991.
- University of North Carolina, Chapel Hill, invited talk at a work shop on almost everywhere convergence, November 7-11, 1991.
- MSRI, Berkeley, California, February, 1992, address at workshop on Amenable Ergodic Theory.
- University of New South Wales, Sydney, Australia, September, 1992, two talks in the Analysis Seminar Series.
- University of Newcastle, Newcastle, Australia, September, 1992, one talk in the Analysis Seminar.
- SUNY at Albany, Colloquium Talk, February, 1993.
- Ohio State University, Conference on Convergence in Ergodic Theory and Probability, June, 1993, short talk.
- University of Western Ontario, Colloquium, January, 1994.
- University of Toronto, special seminar talk, January, 1994.
- University of Florida, Gainesville, Colloquium talk, February, 1994.
- University of South Florida, Tampa, Colloquium talk, February, 1994.
- Kansas State University, Regional AMS meeting, invited talk in a special session on ergodic theory, March, 1994.
- University of Illinois, Urbana-Champaign, Colloquium talk, March, 1994.
- Mathematical Institute, University of Warwick, Coventry, England, visitor, August, 1994.
- University of Zimbabwe, Harare, Zimbabwe, August, 1994, invited talks on ergodic theory.
- Wabash Seminar, Conference talk, Wabash College, Indiana, December, 1994.
- Ohio State University, invited talk in Ergodic Theory and Probability Seminar, February,1995.
- University of Maryland, Departmental Colloquium, March, 1995.
- DePaul University, Regional AMS meeting, invited talk in a special session on ergodic theory, March, 1995.
- University of Illinois, Departmental Colloquium, Mathematics in Science and Society Series, Fall, 1995.
- University of Memphis, Regional AMS meeting, invited talk in a special session on ergodic theory, March, 1997.
- Ohio State University, invited talk in the Ergodic Theory and Probability Seminar, May, 1997
- University of British Columbia, Special Address at the Conference in honor of the retirement of Edmond Granirer, August, 1997
- Northwestern University, invited hour talk at the Conference on Probability, Ergodic Theory, and Analysis in honor of the retirement of Alexandra Bellow, October, 1997.
- University of Florida, Gainesville, February, 1998, Departmental Colloquium.
- Pennsylvania State University, University Park, talk in the Dynamical Systems Seminar in the Mathematics Department, March, 1998.
- Ben Gurion University of the Negev, Beer Sheva, Israel, Departmental Colloquium, May, 1998.
- Hebrew University, Jerusalem, Israel, Ergodic Theory Seminar, invited talk, May, 1998.
- The Technion (Israel Institute of Technology), Haifa, Israel, Departmental Colloquium and a seminar talk, May, 1998.
- DePaul University, Regional AMS meeting, invited talk in a special session on ergodic theory, September, 1998.
- University of Maryland, dynamics seminar talk, November, 1998.
- University of Illinois, Urbana-Champaign, Sectional Meeting of the AMS, March, 1999, invited talk in the session on Wavelets and Multiresolution, organized by Tian He.
- Meeting of Chairs and Heads of Mathematics Departments, November, 1999, talk on Asynchronous Learning, Distance Education, and Programs at UIUC.
- Northwestern University, Plenary talk, Meeting on Stochastic Processes and Harmonic Analysis, June, 2000.
- University of Memphis, special talk, meeting on ergodic theory and dynamical systems, April, 2001.
- Purdue University, probability theory seminar, April, 2001.
- Ohio State University, ergodic theory seminar, April, 2001.
- University of Goettingen, plenary talk, workshop on non-hyperbolic dynamical systems, June, 2000.
- Williams College, special talk, special session in ergodic theory, regional AMS meeting, October, 2001.
- Indiana University, Sectional Meeting of the AMS, invited talk in the special session on ergodic theory, April, 2003.
- National Technical University of Athens, Athens, Greece, invited talk, September, 2003.
- University of Crete, Crete, Greece, invited talks, October, 2003.
- University of North Carolina, Chapel Hill, Sectional Meeting of the AMS, invited talk in the special session on ergodic theory, October, 2003.
- University of Missouri, Columbia, invited seminar talk, analysis seminar, February, 2004.
- Beijing University, Beijing, China, departmental colloquium, May, 2005.
- Mathematics Institute, Chinese Academy of Sciences, Beijing, China, analysis seminar, May, 2005.
- Harbin Institute of Technology, Harbin, Manchuria, China, departmental colloquium, May, 2005.
- Shandong University, Jinan, China, departmental colloquium, May, 2005.
- Shanghai Normal University, Shanghai, China, career planning seminar, May, 2005.
- Shanghai Jiaotang University, Shanghai, China, career planning seminar, May, 2005.
- University of Missouri, Columbia, analysis seminar, August, 2005.
- Cornell University, Center for Applied Mathematics, Colloquium, November 2005
- DePaul University, Chicago, International Conference on Harmonic Analysis and Ergodic Theory, in Honor of Roger Jones and Marshall Ash, invited talk, December, 2005
- Regional meeting of the Canadian Mathematics Society, Victoria, BC, invited talk, December, 2005.
- EU Conference on Harmonic Analysis, Zakopane, Poland, invited talk, January, 2006.
- Wroclaw University, invited seminar talks, January, 2006.
- University of Kentucky, Lexington, colloquium, March, 2006.
- University of Louisville, colloquium, March, 2006.
- Ohio State University, analysis seminar, March, 2006
- Sectional meeting of the AMS, Cincinnati, Ohio, invited talk in the special session on ergodic theory, October 2006.
- University of Maryland, dynamics seminar, November, 2006
- National meeting of the Canadian Mathematics Society, Toronto, special session invited talk, December, 2006.
- February Fourier Talks, University of Maryland, program speaker, February, 2007.
- University of Maryland, colloquium talk, March, 2007.
- SUMIRFAS, Texas A&M University, invited talk, August, 2007.
- Taiwan National University, Taipei, Taiwan, October 2007.
- University of North Carolina, Chapel Hill, colloquium and opening talk for the 2008 Probability and Ergodic Theory Workshop organized by Idris Assani, February, 2008.
- Ohio State University, analysis seminar, February, 2008.
- University of Notre Dame, colloquium, March, 2008.
- Indiana University, analysis seminar, December, 2008.
- IUPUI (Indiana University- Purdue University at Indianapolis), colloquium, December, 2008.
- University of Alberta, Edmonton, plenary talk, Laufest, May, 2009.
- Harmonic Analysis Workshop, Wayne State University, November 2009.
- Analysis Seminar, University of East Anglia, Norwich, UK, January 2010.
- Dynamical Systems Seminar, Imperial College, London, UK, January, 2010.
- Denker Seminar, Pennsylvania State University, October, 2010.
- Northestern University, Dynamical Systems seminar, November, 2010.
- Ohio State University, Analysis Seminar, February 2011.
- George Washington University, Analysis Seminar, February, 2011.
- Butler University, Colloquium, March 2011.
- Oklahoma State University, Analysis Seminar, March 2011.
- University of Memphis, Analysis Seminar, March 2011.
- Conference on Ergodic Theorems, Group Actions, and Applications, Be'er Sheva University, Israel, May 2011.
- Purdue University, Analysis seminar, October 2011.
- George Washington University, Analysis seminar, November 2011.
- George Washington University, Colloquium, November 2011
- University of Memphis, Analysis seminar, April 2012.
- University of Louvain la Neuve, Belgium, Analysis Seminar, August 2012.
- University of Louvain la Neuve, Belgium, Colloquium, August 2012.
- Ohio State University, Analysis Seminar, October, 2012
- Sectional Meeting of the AMS, Akron, OH, invited talk in the Special Session on Separate Continuity vs. Joint Continuity, October, 2012
- Ohio State University, Analysis Seminar, March, 2013
- University of North Carolina, Chapel Hill, invited talk, Ergodic Theory Workshop organized by Idris Assani, March, 2013.
- SUNY Albany, Analysis Seminar, July, 2013.
- DePaul University, Colloquium, and Analysis Seminar, September, 2013.
- University of Maryland, Dynamical Systems Seminar, October, 2013
- George Washington University, Analysis Seminar, October, 2013
- AMS Sectional Meeting, Louisville, Special Session on Ergodic Theory and Topological Dynamics, October, 2013.
- UCLA, T. Tao Seminar, October, 2013.
- UC Irvine, Analysis Seminar, October, 2013.
- Special Session in Ergodic Theory and Symbolic Dynamics, AMS National Meeting, Baltimore, MD, January, 2014.
- Special address on Mathematics Education from a Global Perspective, Fourah Bay College, Freetown, Sierra Leone, March 2014.
- University of Toruń, Mathematical Department of the Nicolaus Copernicus University, Toruń, Poland, special talk in Meeting on Ergodic Theory and Dynamical Systems, May, 2014
- Institute of the Polish Academy of Sciences, Wroclaw, Poland, seminar, May 2014
- Institute of Mathematical Stochastics, Technical University of Dresden, Dresden, Germany, seminar, May 2014
- Institute of the Polish Academy of Sciences, Warszawa, Poland, seminar, May 2014.
- Ohio State University, ergodic theory seminar, November 2014.
- Special Session on Number Theory in Ergodic Theory and Dynamical Systems, AMS Sectional Meeting, George Washington University, March, 2015
- Colloquium and Analysis Seminar, University of Missouri - Columbia, March, 2015.
- Dynamical Systems, Ergodic theory, and Probability Conference in memory of Nikolai Chernov, University of Alabama, Birmingham, May 2015
- Invited Talk, Ergodic Theory and Combinatorics Conference, University of Agder, Kristiansand, Norway, June 2015
- Seminar, University of Paris-Sud, Orsay, June 2015

- Short talk at AMS Meeting, San Francisco, January 1981.