1993 | January | Contractive zero divisors, Colloquium, Brown University, Providence, RI. |

February | Contractive zero divisors, Colloquium, Uppsala University, Uppsala, Sweden. | |

March | Contractive zero divisors, Colloquium, University of Linköpping, Sweden. | |

April | Invariant subspaces in Bergman spaces, Stockholm Analysis Seminar, Stockholm University. | |

May | The Riemann function and its applications, Analysis Seminar, Royal Institute of Technology, Stockholm Work of H.S. Shapiro, Conference in honor of the retirement of H.S. Shapiro, Royal Institute of Technology, Stockholm. First paper of I. Fredholm, Colloquium, University of Jyvaskyla, Finland. | |

1994 | January | The Reflection principle revisited, AMS winter meeting, Cincinnati, Special session on holomorphic differential equations. |

July | Extremal problems in Bergman spaces, one hour invited lecture at the AMS Summer Conference on Bergman Spaces, Mount Holyoke, MA. | |

1995 | January | The Reflection principle revisited, Colloquium, University of Maryland, College Park, MD. |

February | The Reflection principle revisited, Colloquium, University of Kentucky, Lexington, KY. | |

March-May | A short course on “Holomoprhic PDE and Potential Theory,” Universidad de La Laguna (Spain). | |

June | The Reflection principle revisited, two one-hour lectures, Universidad de Autonoma Barcelona, Spain. | |

1996 | February-March | The reflection of harmonic functions across real-analytic hypersurfaces, Northwestern University, Evanston, IL. |

September | The isoperimetric inequality revisited, September 20, Trondheim, Norway. | |

Best approximation in the mean by analytic functions, Conference on Bergman Spaces, invited. | ||

1997 | February | The Schwarz reflection principle revisited. |

Best approximation in the mean by analytic functions, Washington University, St. Louis. | ||

1998 | January | The reflection principle, Colloquium, University of Sydney, Australia, invited. |

Szegö’s theorem on extension of expansions of spherical harmonics, Colloquium, University of New South Wales, Australia, invited. | ||

March | Approximation of Continuous functions in L^{1}-norm, AMS Meeting, Manhattan, Kansas. | |

Analytic continuation of Dirichlet Series, AMS meeting, Louisville, Kentucky. | ||

July | Approximation in the mean by harmonic functions, Analysis Seminar, University of Michigan, invited. | |

October | The reflection principle, Analysis Seminar, University of Illinois, Chicago, invited. | |

1999 | January | Approximation in the mean, AMS winter meeting, San Antonio, TX. |

May | Conference on PDE at Carmiel College, Israel. | |

Participant in the Round Table on How to write mathematics, San Antonio, TX. | ||

Bounded Approximation by Analytic and Harmonic Functions, Colloquium at Technion in Haifa, Israel. | ||

Three lectures on Approximation in the mean by harmonic functions--Colloquiums at Technion and Bar Ilan, Israel University, and a one-hour invited talk at the Conference on PDE and Approximation Theory | ||

December | Uniform approximation by harmonic functions, one-hour invited talk at Mittag-Leffler Institute, Sweden | |

2000 | June | Best approximation by harmonic and analytic functions, invited talk at the Joint AMS-Scandinavian Math Society meeting in Odense, Denmark. |

2001 | January | Approximation in the mean by harmonic functions, AMS winter meeting, New Orleans. |

May | Szegö’s theorem and extensions of solutions of holomorphic PDEs, Colloquium, Brown University. | |

October | An inverse problem for double layer potentials, Colloquium, Oklahoma State University, Washington University in St. Louis. | |

2002 | September | Three questions on harmonic functions, VOTCAM conference, University of Richmond, invited principal speaker, 2 lectures. |

October | An inverse problem for double layer potentials, CIRM conference on spaces of analytic functions and operator theory, Marseilles, invited 1hour talk. | |

December | The isoperimetric inequality revisited, SUNY at Albany, invited colloquium talk. | |

2003 | March | Weak compactness in star invariant subspaces, SEAM, Principal Speaker, 1 hour invited talk. |

June | Weak compactness in star invariant subspaces, AMS-RMSE joint meeting, Seville, invited talk | |

July | The isoperimetric inequality revisited, Function Theory Conference, Metz, France, invited talk. | |

October | Remarks on the Bohr Phenomenon, AMS meeting in Chapel Hill, NC, special session, invited. | |

Zeros of Harmonic Polynomials, Colloquium, Seton Hall University, invited. | ||

2004 | February | Zeros of rational harmonic functions with applications to gravitational microlensing, Functiontheorie meeting, Oberwolfach, 1 hr invited talk. |

June | Extremal problems for analytic functions in Bergman spaces, two invited lectures at Bar Ilan University, Ramat Gan, Israel. | |

September | Zeros of rational harmonic functions and gravitational microlensing, Distinguished Visitor Lectures, Bucknell University. | |

October | Zeros of rational harmonic functions and gravitational microlensing, Colloquium, SUNY at Albany, invited. | |

November | The isoperimetric inequality revisited, Colloquium, Bucknell University, invited. | |

2005 | January | On the maximal number of zeros of certain rational harmonic functions, Special Session at the AMS Winter meeting in Atlanta, invited. |

April | On the maximal number of zeros of certain rational harmonic functions, SEAM, invited. | |

May | Research in Pairs with Harold S. Shapiro and M. Putinar, Oberwolfach, invited. | |

June | The isoperimetric inequality and some free boundary problems, one hour plenary lecture at the CMFT 2005 conference, Joensuu. | |

July | Workshop on gravitational microlensing, AIM Palo Alto, invited. | |

September | Valency of certain harmonic functions and gravitational microlensing, Texas Tech University, Colloquium talk, invited. | |

October | Some algebraic aspects of the Dirichlet problem, Conference on recent advances in operator related function theory, a plenary talk, Madrid. | |

Zeros of rational harmonic functions and microlensing, Colloquium talk, Virginia Tech. | ||

2006 | January | Lightning bolts and the Dirichlet problem, Conference on Complex Analysis and Dynamical Systems, Naharia, Israel, invited talk. |

Algebraic aspects of the Dirichlet problem, Conference on Planar Harmonic mappings, Technion, Haifa, a plenary talk. | ||

Algebraic aspects of the Dirichlet problem, Colloquium talk, Virginia Tech, invited. | ||

From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, Mississippi State University, invited. | ||

February | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, University of South Florida, invited. | |

March | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, University of California at San Diego, invited. | |

From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, George Washington University, invited. | ||

From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, University of Tennessee, invited. | ||

April | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, University of Delaware, invited. | |

Dirichlet problem with the rational data, AMS Meeting in Durham, NH, Special Session on Complex Analysis, invited. | ||

May | Algebraic aspects of the Dirichlet problem, Complex and Harmonic Analysis Conference, Thessaloniki, Greece, invited talk. | |

September | Potential theory viewed from the complex space, Conference on Complex Analysis and Potential Theory, Istanbul, Turkey, a plenary talk. | |

2007 | January | Gravitational lensing by elliptical galaxies and the Schwarz function. Dangriga, Belize, invited talk. |

Algebraic aspects of the Dirichlet problem, R. P Gilbert 75th birthday Conference, Orlando, Florida, invited talk. | ||

May | Gravitational lensing by elliptical galaxies and the Schwarz function, Conference on new trends in complex and harmonic analysis, Bergen, Norway, a plenary talk. (PDF) | |

Nonlinear extremal problems for analytic functions, Conference on extremal problems in real and complex analysis, Moscow, Russia, invited talk. (PDF) | ||

July | Gravitational lensing by elliptical galaxies and the Schwarz function, Quadrature domains and Laplacian growth in modern physics symposium, BIRS, Banff, invited 1 hr. talk. (PDF) | |

October | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, University of Tampa, invited. | |

From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, MASS Colloquium talk, Penn State, invited.(PDF) | ||

2008 | March | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Colloquium talk, Los Alamos National Laboratory, invited. |

May | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, 2 hour Colloquium talk for graduate students, University of Cyprus, invited. | |

“Fingerprints” of two-dimensional shapes and lemniscates, Colloquium talk, University of Cyprus, invited. | ||

June | Searching for singularities of solutions of the Dirichlet problem: recent developments, Workshop on Complex Analysis and Mathematical Physics, Nordfjordeid, Norway, a plenary talk. | |

August | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, A Workshop on Laplacian growth and related topics, Centre de recherches mathematiques, Universite de Montreal, a plenary talk. | |

December | Searching for singularities of solutions of the Dirichlet problem: recent developments, A Conference on Hilbert Spaces of Analytic Functions, Centre de recherches mathematiques, Universite de Montreal, a plenary talk. | |

2009 | January | “Fingerprints” of the two-dimensional shapes and lemniscates, an invited talk at the Special Session on Function Theoretic Operator Theory, Joint Mathematics Meeting, AMS, Washington, DC, 2009. |

May | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Department of Physics, Hebrew University, Jerusalem, a colloquium talk, invited. | |

“Fingerprints” of two-dimensional shapes and lemniscates, Complex analysis and Dynamical Systems IV, Naharia, Israel, an invited talk. | ||

Searching for singularities of solutions of the Dirichlet problem: recent developments, University of Cyprus, a colloquium talk, invited. | ||

June | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Los Alamos National Laboratory, Los Alamos, a colloquium talk, invited. | |

September | Analytic continuation in classical potential theory, Norwegian Fall School in Analysis for Ph D students and young researchers, Trondheim, Norway, a mini-course, invited. | |

October | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, Duke University, a colloquium talk, invited. | |

On a uniqueness property of harmonic functions, Classical Analysis in One and Several Complex Variables, Chapel Hill, an invited talk. | ||

December | From the fundamental theorem of algebra to astrophysics; a “harmonious” path, Renyi Institute of Hungarian Academy of Sciences, a colloquium talk, invited. | |

Classical Potential Theory and Holomorphic PDE, Erwin Schroedinger Institute, Vienna, an invited talk. | ||

2010 | March | Malmheden's theorem revisited, UCSD at La Jolla, a colloquium talk. |

April | Malmheden's theorem revisited, Albuquerque, NM, AMS Spring 2010 Meeting, Special Session on Geometric Function Theory, invited. | |

May | Malmheden's theorem revisited, Conference on Complex Analysis, UIUC, an invited talk. | |

October | From the fundamental theorem of algebra to astrophysics; a “harmonious” path, UCF, Orlando, a colloquium talk, invited. | |

November | “Fingerprints” of the two-dimensional shapes and lemniscates, A Workshop on Integrable and Stochastic Laplacian Growth in Modern Mathematical Physics, Banff, an invited talk. | |

December | “Fingerprints” of the two-dimensional shapes and lemniscates, Complex Analysis and Mathematical Physics, an international conference, Chillan, Chile, a plenary talk. | |

2011 | February | “Fingerprints” of the two-dimensional shapes and lemniscates, University of New Mexico a colloquium talk. |

From algebra to astrophysics, UNM-PNM Statewide Mathematics Contest Public Lecture, Albuquerque, an invited public lecture (canceled due to the inclement weather), (PDF). | ||

From algebra to astrophysics,, PiMuEpsilon Mathematics Club Lecture, University of South Florida. | ||

April | From the fundamental theorem of algebra to astrophysics; a “harmonious” path, IUPUI, Indianapolis, a colloquium talk, invited. | |

“Fingerprints” of the two-dimensional shapes and lemniscates, an invited talk at the Special Session on Complex Analysis and Banach Algebras, AMS Spring Eastern Sectional Meeting, Worcester, Massachusetts. | ||

May | Linear extremal problems in Banach spaces of analytic functions, Complex Analysis and Dynamical Systems V, Akko, Israel, a plenary talk, invited. | |

June | Extremal problems for nonvanishing functions in Bergman space, Computational Complex Analysis and Approximation Theory, Protaras, Cyprus, an invited talk. | |

Linear extremal problems in Banach spaces of analytic functions, Complex Analysis and Potential Theory, Centre de Recherches Mathematiques, Montreal, a 1 hr invited talk. | ||

September | Linear extremal problems in Banach spaces of analytic functions, Workshop on Univalent Functions and Control, Mittag-Leffler Institute, Djursholm, Sweden, a 1hr invited talk. | |

From the fundamental theorem of algebra to astrophysics; a “harmonious” path, University of Lund, Lund, Sweden, a colloquium talk, invited. | ||

December | From algebra to astrophysics, a public lecture for high school seniors, Mittag-Leffler Institute, Djursholm, Sweden, invited. | |

The Isoperimetric inequality and free boundary problems, Workshop on Geometric Analysis and Mathematical Physics, Mittag-Leffler Institute, Djursholm, Sweden, a 1 hr invited talk. | ||

2012 | March | Holomorphic PDE in C^n, Potential Theory and Hele-Shaw Processes in R^n, a mini-course (jointly with E. Lundberg), Harmonic and Complex Analysis and Applications 2012, Tenerife, Canary Islands, Spain, invited. |

July | Holomorphic PDE in C^n: J. Leray's theory of propagation of singularites, 9th AIMS Conference on Dynamical Systems, Differential Equations and Applications, Orlando, FL, invited. | |

August | Extremal domains for the analytic content, Workshop on Complex Analysis and Integrable Systems, in memory of B. Korenblum, Mittag-Leffler Institute, Djursholm, Sweden, 1hr, invited. | |

September | Extremal domains for the analytic content, Conference on Complex and Harmonic Analysis in honor of M. Katsoprinakis, University of Crete, Heraklion, Crete, 1hr, invited. | |

October | From the Fundamental Theorem of Algebra to astrophysics; a “harmonious” path, a colloquium talk, University of Michigan, Ann Arbor, invited. | |

December | Analytic functions in Smirnov classes with real boundary values, Canadian Mathematical Society Winter Meeting, Montreal, invited. | |

2013 | March | Holomorphic PDE and Potential Theory , a one-hour tutorial, 2d International Workshop on Nonlinear and Modern Mathematical Physics, Tampa, invited. |

May | An overdetermined boundary value problem, Conference on Complex Analysis and Dynamical Systems VI, Naharia, Israel, invited. | |

June | Algebraic aspects of the Dirichlet problem, Conference in honor of Amtony G. O'Farrell, Maynooth College, 1 hour invited talk. | |

Two - dimensional shapes and lemniscates, An International Workshop on Conformal Geometry in Mapping, Imaging and Sensing, Imperial College , London, 1 hour invited talk. | ||

August | Selected problems in classical function theory, Invariant Subspaces of the Shift Operator, Centre de Recherches Mathematiques, Montreal, Canada, 1 hr invited talk. | |

September | An Overdetermined boundary value problem, Norwegian Institute of Science and Technology, Trondheim, 1 hr invited talk. | |

December | From the fundamental theorem of algebra to astrophysics; a “harmonious” path, Optimization, Moments Problems and Geometry II, Graduate Students Winter School/Workshop, National University of Singapore, Singapore, an invited talk. | |

2014 | January | The fundamental theorem of algebra and a problem in graviational lensing. S.- H. Rhie's work, 18th Internalional Conference on Microlensing, Santa Barbara, an invited talk. |

February | Some open problems for polynomials of one and several variables, Workshop on Dirichlet series and function theory in polydisks, MFO Oberwolfach, an invited talk. | |

March | Boundary behaviour of universal Taylor seroes, AMS Special Session on Invariant Subspaces in Function Spaces, Knoxville, an invited talk. | |

April | The Fundamental Theorem of Algebra, Complex Analysis and ... Astrophysics, International Conference on Complex Analysis and Related Fields, St. Petersburg, Russia, an invited plenary talk. | |

May | The Fundamental Theorem of Algebra, Complex Analysis and ... Astrophysics, ISM Conference, Quebec City, Canada, a keynote invited talk. | |

June | Some open problems for polynomials of one and several complex variables, Complex and Harmonic Analysis Workshop, Holon, Israel, an invited talk. | |

“Isoperimetric sandwiches” and function theory, Annual Meeting of the Israel Math. Soc.,Special Session on Mathematics of M. Schiffer, invited . | ||

July | Boundary behaviour of universal power series, Perspectives of Modern Complex Analysis, Banach Center, Bedlewo, Poland, an invited talk. | |

October | Problems for polynomials in one and several variables, Workshop on Hausdorff Geometry and Critical Points, Institute of Mathematics and Informatics, Sofia, Bulgaria, an invited talk. | |

Problems for polynomials in one and several variables, Workshop on Optimal Point Configurations and Applications, Schroedinger Institute, Vienna, Austria, an invited talk. | ||

November | “Fingerprinting”the lemniscates, Red Raider Mini-symposium: Complex Analysis, Potential Theory Special Functions and Applications, Texas Tech, Lubbock, a plenary talk. | |

The isoperimetric inequality revisited, 2014 Lecture Series at the University of Tampa, an invited talk. | ||

2015 | January | “Isoperimetric sandwiches” in function-theoretic operator theory, AMS Annual Winter Meeting, Special Session on Progress in Multivariate Operator Theory, San Antonio, invited. |

March | From C.- F. Gauss to A. Einstein, from algebra to realativity and astrophysics via complex analysis, 2015 USF Distinguished University Professor Lecture. | |

April | “Between two truths of the real domain, the easiest and shortest path quite often passes through the complex domain.” P. Painleve, 1900. FAU, Boca Raton, a seminar talk. | |

“Between two truths of the real domain, the easiest and shortest path quite often passes through the complex domain.” P. Painleve, 1900. FIU, Miami, a seminar talk. | ||

From C.- F. Gauss to A. Einstein, from algebra to relativity and astrophysics via complex analysis, FAU, Boca Raton, a colloquium talk. | ||

May | Approximating z* by analytic functions, Complex Analysis and Dynamical Systems VII, Naharia, Israel, an invited talk. | |

June | Approximating z* by analytic functions, Completeness Problems, Carleson Measures and Spaces of Analytic Functions, Mittag-Leffler Institute, Djursholm, Sweden, an invited 1 hr talk. | |

October | The Fundamental Theorem of Algebra, Complex Analysis and ... Astrophysics, University of Bergen, a colloquium talk. | |

Isoperimetric sandwiches and some free boundary problems via approximation by analytic and harmonic functions, a mini course, University of Bergen,(PDF), (PDF), (PDF), (PDF) | ||

November | "Fingerprinting" the lemniscates, Universitat Autonoma Barcelona, a colloquium talk. | |

December | "Fingerprinting" the lemniscates, Stockholm University, Analysis Seminar. | |

A variation on the theme of analytic continuation, Stockholm University, a colloquium talk. | ||

2016 | January | “Isoperimetric sandwiches”, free boundary problems and approximation by analytic and harmonic functions, Joint Analysis Seminar, McGill, Montreal. |

February | The Fundamental Theorem of Algebra, Complex Analysis and ... Astrophysics, Universite de Montreal, a colloquium talk. | |

July | The spectral properties of several classical function-theoretic operators and gemetry. 2016 CRM Summer School on Spectral Theory and Applications, Laval University, a 1hr invited talk. | |

“Isoperimetric sandwiches”, free boundary problems and approximation by analytic and harmonic functions, A Conference on New Trends in Approximation Theory, Fields Institute, Toronto, a 1hr invited talk. | ||

Harmonic polynomials and rational functions: recent progress, open problems and applications, 7th ECM, Mini-Symposioum on Zeros of Harmonic Functions, Berlin, an invited talk. | ||

November | The Fundamental Theorem of Algebra, Complex Analysis and ... Astrophysics, Brown University, an invited talk. | |

2017 | January | A note on the spectral area of Toeplitz operators, Joint AMS and MAA Winter Meeting, Special Session on Operator Theory, Function Theory and Models, Atlanta, invited. |

July | Vanishing of reproducing kernels in spaces of analytic functions, Mathematics Congress of Americas, Session on Operators on Function Spaces, Montreal, invited. | |

September | Vanishing of reproducing kernels in spaces of analytic functions, AMS Southeastern Meeting, Session on Operators on Complex Analysis, Harmonic Analysis and Approximation Theory, Orlando, FL, invited. |