# Faculty News Briefs

### December 2010

In November 2010 Professor Tom Braden attended the workshop on Topological Methods in Toric Geometry, Symplectic Geometry and Combinatorics at the Banff International Research Station. He gave a talk titled "Geometry and Representation Theory of Hypertoric Varieties."

On November 4, 2010 Professor Michael Lavine addressed the We Know Statistics Software fall seminar at Smith College.

On November 12, 2010 Professor Andrea Nahmod gave a talk at the PDE Seminar at University of California Santa Barbara. On November 13-14, 2010 Andrea attended the Southern California Analysis & PDE (SCAPDE) meeting at UCLA in Los Angeles, CA, where she also gave a talk. The organizers of this meeting were Terence Tao, Rowan Killip, Monica Visan, John Garnett, Jacob Sterbenz, Christoph Thiele, Hans Lindblad, and Jacob Sterbenz.

On December 10, 2010 Professor Franz Pedit gave two talks at the University of Vienna titled "Curvature" and "Surfaces of Constant Mean Curvature: Analysis, Geometry and Experiment."

Professor Eric Sommers visited the University of Notre Dame on November 11 and 12, 2010. While there, he delivered a seminar talk titled "Counting B-Stable Ideals and Non-Crossing Partitions" and a colloquium titled "A Family of Representations for Finite Reflection Groups."

### November 2010

On October 7, 2010 Professor Tom Braden gave a colloquium talk in the Department of Mathematics at University of Connecticut. His talk was titled "Representation Theory of Hyperplane Arrangements."

During the period October 20-21, 2010 Professor Krista J. Gile attended a SAMSI workshop on Complex Networks Modeling at SAMSI in Research Triangle Park, NC. On October 21 she gave an invited talk titled "Self-Consistent Network Model-Assisted Prevalence Estimation from Respondent-Driven Sampling Data."

On October 4, 2010 Professor Michael Lavine gave a seminar in the Department of Statistics at Harvard University. His talk was titled "Subjective Likelihood for an Assessment of Climate Change in the Ocean."

During the period August 27-31, 2010 Professor Franz Pedit attended the conference Differential Geometry and Its Applications in Brno, Czech Republic. He gave a plenary talk titled "Integrable Aspects of Constant Mean Curvature Surfaces."

During the period October 21-24, 2010 Professor Jenia Tevelev attended the conference Compact Moduli and Vector Bundles at the University of Georgia in Athens. He gave a talk titled "Effective Divisors on M_{0,n}."

During the period October 28-29, 2010 Professor Bruce Turkington was a plenary speaker at the 2010 MetStroem Program Meeting at the Freie Universitaet Berlin. The MetStroem is a funded working group of German researchers in meteorology and climate prediction involved in the modeling and computation of large-scale geophysical fluid dynamics. The title of his lecture was "A Statistical Mechanical Approach to Parameterization and Closure of Underresolved Dynamics." On October 6, 2010 he also gave a colloquium lecture on the same topic at the Center for Atmosphere-Ocean Science, Courant Institute of Mathematical Sciences, New York University.

### October 2010

The book by Professor Richard S. Ellis titled "Entropy, Large Deviations, and Statistical Mechanics" was published by Springer-Verlag New York in 1985 in the series Grundlehren der mathematischen Wissenschaften (Fundamental Principles of Mathematical Sciences). It was reprinted in 2006 in the series Classics in Mathematics. On September 27, 2010 Richard was informed that Springer-Verlag had finalized an agreement with World Publishing Corporation, China, which would like to reprint this title in a print-run of up to 1000 copies.

On September 29, 2010 Professor Michael Lavine gave a deposition as an expert witness in a product liability law suit.

Professor Eric Sommers attended the AMS sectional meeting at Syracuse University on October 2-3, 2010 and gave a talk entitled "Exterior Powers of the Reflection Representation in Springer Theory." Also, his grant application to the NSA was funded this summer.

### September 2010

Professor Eduardo Cattani was the co-director of a Summer School and Conference on Hodge Theory, which took place during the period June 14 - July 2, 2010 at the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy. He also gave two five-lecture courses during the School, titled *Introduction to K√ÉÔøΩ√Ç¬§hler Manifolds* and *Introduction to Variations of Hodge Structure.* There were more than 100 participants in the School including more than 50 participants from developing countries. The School was co-sponsored by the US National Science Foundation and the Clay Mathematics Institute. The poster for the School is available at http://www.math.umass.edu/~cattani/ictp_poster.pdf. Founded in 1964, the Abdus Salam International Centre for Theoretical Physics (ICTP) operates under the aegis of two United Nations Agencies: UNESCO and IAEA and is regularized by a seat agreement with the Government of Italy. Its goals are the following:

\t(1) Foster the growth of advanced studies and research in physical and mathematical sciences, especially in support of excellence in developing countries;

\t(2) Develop high-level scientific programs keeping in mind the needs of developing countries, and provide an international forum of scientific contact for scientists from all countries;

\t(3) Conduct research at the highest international standards and maintain a conducive environment of scientific inquiry for the entire ICTP community.

Professor Qian-Yong Chen gave a talk on July 15, 2010 at the SIAM annual meeting. His NSF proposal was funded in August.

On June 30, 2010 Professor Richard S. Ellis gave a colloquium talk in the Berlin Probability Colloquium in Berlin, Germany. This colloquium is joint with Technical University Berlin, Humboldt University, and Weierstrass Institute for Applied Analysis and Stochastics. His talk was an introduction to the theory of large deviations titled *From Large Deviations to Statistical Mechanics: What Is the Most Likely Way for an Unlikely Event To Happen?*

Professor Paul Hacking gave a talk at the conference Rationally Connected Varieties and Birational Geometry, which took place May 21-22, 2010 at Princeton University. The title of his talk was *Deformations of Log Canonical Surface Singularities.* Paul also gave a talk at the conference Vector Bundles on Algebraic Curves: New Invariants and Stability Conditions, which took place June 14-18, 2010 at Instituto Superior Tecnico in Lisbon, Portugal. The title of his talk was *Exceptional Vector Bundles Associated To Degenerations Of Surfaces.*

Professor Panos Kevrekidis had a very busy summer and beginning of the fall semester. During the period June 25-29, 2010 Panos participated in the second International Meeting on Nonlinear Waves and Their Applications held in Beijing, China. He organized a session there on Bose-Einstein Condensation and delivered a talk on his recent work on the topic. Graduate student Chenyu Wang also participated in the meeting. Subsequently, Panos visited the University of Heidelberg and the University of Hamburg in July and August 2010 in the framework of the last year of his Humboldt Research Fellowship. During that time period he was also one of the principal speakers at the workshop on Coherent Structures in Evolutionary Equations, held in Leiden, Netherlands from July 12 until July 16, 2010. Then in the beginning of September he participated in the conference Dynamics in Samos, held in Samos, Greece. At that conference he received the award for the biennial Stephanos Pnevmatikos Prize and delivered an invited lecture on dark solitons and vortices in BECs. Finally, during the period September 7-10, 2010 he participated in the Dynamics Days conference held in Bristol, UK, where he was one of the plenary speakers.

Professor Daeyoung Kim gave an invited talk at the Thirteenth Meeting of New Researchers in Statistics and Probability, which was held at University of British Columbia during the period July 27-30, 2010. The title of his talk was *Using Confidence Distribution Sampling to Visualize Confidence Sets.* He also gave a topic-contributed talk at JSM 2010 in the Topic-Contributed Papers Session on Recent Developments in Mixture Models and Applications (IMS, Section on Quality and Productivity), which was held in Vancouver, British Columbia, Canada. The title of his talk was *Selection of Consistent Roots to the Likelihood Equation in Finite Mixtures of Location-Scale Distributions.*

Professors Rob Kusner and Bill Meeks lectured on constant mean curvature surfaces in Banff, Alberta, Canada at the BIRS workshop on Semilinear PDE and the diGiorgi Conjecture during the second week of August 2010.

Professor Ivan Mirkovic attended a three-week conference at Kavli Instite for Physics in Santa Barbara, CA as well as the following three additional conferences: Double Affine Hecke Algebras and Algebraic Geometry, held at MIT, May 17-21, 2010; Sheaves in Representation Theory, held on Isle of Skye in Scotland, May 23-28, 2010; Whittaker Functions, Crystal Bases, and Quantum Groups, held at the Banff International Research Station in Canada, June 6-11, 2010. He gave talks on modular representation theory.

Professor Eric Sommers participated in the Fifth International Conference on Representation Theory, which was held in Xi'an, China from August 9 to August 14, 2010. He gave a one-hour talk entitled *Exterior Powers of the Reflection Representation in Springer Theory.* In April 2010 he visited the University of Caen in France for a week. While there he delivered a talk entitled *A Duality for Nilpotent Orbits.*

Professor Jenia Tevelev received the following two grants: NSF grant DNS-0963853, AGNES - Algebraic Geometry Northeastern Series (with Paul Hacking as co-PI) and the Research Leadership in Action grant from the University of Massachusetts.

Professor Bruce Turkington participated in the Oberwolfach workshop on the Mathematical Theory and Modeling in Atmosphere-Ocean Science during the period August 8-14, 2010.

### May 2010

Emeritus Professor Floyd Williams co-edited a research monograph, "A window into zeta and modular physics," with Professor Klaus Kirsten of Baylor University. The book, which is published Cambridge University Press, contains lectures and research articles on zeta functions, modular forms, and vertex operator algebras, with various applications to physics, including black holes and conformal field theory. It is part of the distinguished MSRI (Mathematical Sciences Research Institute, Berkeley) series (volume 57). Besides the lectures of Kirsten and Williams, this volume also contains articles by former graduate students, Dr. Shabnam Beheshti and Dr. Jennie D'Ambroise.

Associate Tom Braden gave a talk in the geometry/physics seminar at Northwestern University on May 11, on "Deformations of standard Koszul algebras and localizationin equivariant cohomology". From May 23 to 29, he attended a workshop/conference "Sheaves in representation theory" on the Isle of Skye, Scotland, where he gave a talk entitled "Hypertoric category O".

Professor Panos Kevrekidis participated in the Spring Eastern Sectional Meeting of the AMS, delivering an invited talk on his recent work on dark solitons and vortices in Bose-Einstein condensates. At the SIAM Conference on Mathematical Aspects of Materials Science in Philadelphia, he also gave a minisymposium talk. He then departed for Dresden, Germany where he attended the 8th AIMS Conference on Dynamical Systems, Differential Equations and Applications. There he co-organized a session with Ricardo Carretero of SDSU and Dimitri Frantzeskakis of the University of Athens on *Nonlinear Schrodinger Equations and their Applications,* and he gave an invited talk on his recent work on granular crystals.

Professor Michael Lavine presented a paper with a coauthor at SAND 5, Statistical Analysis of Neuronal Data, in Pittsburgh, May 20-22.

Professor Franz Pedit participated in an Oberwolfach Conference on "Progress in Surface Theory" from May 2 to May 8. He delivered a lectured on "Description of constant mean curvature k-noids with Delaunay ends".

Professor Bruce Turkington participated in a workshop on *Simulation Hierarchies in Climate Modeling* held at the Institute for Pure and Applied Mathematics, UCLA, from May 3 to 7. He gave an invited lecture on *A new approach to statistical closure for complex deterministic dynamics*.

Professor Rob Kusner delivered the closing lecture Moduli Space of Complex Projective Structures and CMC Surfaces at the Mathematische Forschunginstitut Oberwolfach workshop on Progress in Surface Theory during his visit to Germany in May. He also served on a PhD panel at the Technische Universitaet Darmstadt and lectured at the Technische Universitaet Berlin on *Triangulations, Belyi, Abel, etc.: Complex analysis in service of combinatorial geometry.*

Associate Professor Jenia Tevelev delivered a talk *Hypertrees, projections, and moduli of stable curves* at the Texas Algebraic Geometry Seminar (Austin, TX, April 17-18) and at the Algebraic Geometry Workshop in honor of S. Mori (Princeton, May 21-22). Recently, he was awarded a research grant on *Compact Moduli Spaces of Curves and Surfaces* from the National Science Foundation.