- Invited talk at the Conference on Gauge Theories, Monopoles, Moduli Spaces and Integrable Systems in honor of Jacques Hurtubise, Montreal, Quebec, Canada, Aug 21-25, 2017: Title: The K\"ahler Geometry of Bott Manifolds.
- Invited Talk given at: the FIU Winter Conference on Geometry, Topology and Applications, Miami, Florida, Jan. 4-7, 2017: Title: Obstructions for Extremal Sasaki Metrics.
- Invited Lecture given at: the workshop on graded algebra, geometry and related topics in CIMAT Me'rida, Mexico, November 18, 2016: Title: A Panorama of Sasakian Geometry.
- Invited Lecture given at the 21st Symposium on Complex Geometry in Kanazawa, Japan, October 28, 2015: Title: Extremal Sasaki Geometry
- Three Invited Lectures given at: Inaugural Geometry Lectures at CIMAT Me'rida, Mexico, Sept. 30-Oct. 02, 2015: Title: Extremal Sasaki Geometry
- Invited Talk at the conference: Recent Advances in K\"ahler Geometry, at Vanderbilt University, May 18-22, 2015. Title: Moduli Problems in Sasakian Geometry
- Invited talk at the conference on Real and Complex Differential Geometry, Bucharest, Romanian, Sept. 8-12, 2014: Title: Extremal Sasakian Geometry: the Join and Admissible Constructions
- Invited talk at AMS Special Session on Symplectic and Contact Structures on Manifolds with Special Holonomy, Baltimore, MD, Jan. 2014: Sasaki Join Transverse Hamiltonian 2-forms & and Extremal Sasaki Metrics
- Invited talk at AMS Special Session on Manifolds with Special Holonomy and Generalized Geometries, San Diego, CA, Jan. 2013: The Join Construction & Extremal Sasakian Geometry
- Invited Colloquium talk at Universdad del Pais Vasco, Bilbao, Pais Vasco, Spain, July 2012. Einstein Metrics on Spheres.
- Invited talk at the conference: Differential Geometry Days, in honor of Luis A. Cordero, in Santiago de Compostela, Spain, June 27-29, 2012. Extremal Sasakian metrics on S3-bundles over Riemann surfaces.
- Invited talk at the Workshop on Ricci Solitons and Symmetry, at the University of Oklahoma, March 16-18, 2012. Extremal Sasaki Metrics.
- Invited talk at the Conference on Geometric Structures in Mathematical Physics, in Golden Sands, Bulgaria, September 19-26, 2011. Extremal Sasakian Geometry.
- Invited talk at the Workshop on Extremal Kahler Metrics at the Simons Center for Geometry and Physics, Stony Brook NY, March 21-25, 2011. Extremal Sasakian Geometry.
- Invited talk at the conference: Symmetry, Separation, Super-integrability, and Special Functions (to honor the retirement of Willard Miller Jr.), Univ. of Minnesota, Sept. 17-19, 2010. OnToric Contact Geometry.
- Invited talk at the Conference on Kaehler and related geometry, Nantes, France, Nov. 2009. Maximal Tori in Contactomorphism Groups and Extremal Metrics.
- Invited talk at the conference: Extremal Kaehler Geometry, Banff, CAN, June-July 2009. The Kaehler cone versus the Sasaki cone.
- Invited talk at the conference: Kaehler and Sasakian Geometry in Rome, Rome, Italy, June 2009. Sasakian Geometry: the Recent Work of Krzysztof Galicki.