# Faculty News Briefs

### January 2010

Professor Paul Hacking gave a talk entitled *Smoothing Surface Singularities via Mirror Symmetry* at the MSRI workshop *Tropical Structures in Geometry and Physics,* which took place during the period November 30 - December 4, 2009. A video of the talk is available at http://www.msri.org.

Professor Panos Kevrekidis had a busy fall. Panos was one of the principal speakers at the interdisciplinary workshop on periodic oscillations that took place in Granada, Spain during the period October 20-24, 2009. There Panos discussed his recent work on the oscillations and interactions of dark solitons in Bose-Einstein condensates. He also gave a related talk in December at the Condensed Matter seminar in the Department of Physics at UMass. Finally, in November Panos was one of the invited speakers at the workshop on *Lattice Dynamical Systems* that took place at Brown University. In his talk Panos discussed his recent work on the discrete nonlinear Schr√∂dinger equation and its applications, which also constitutes the theme of his recently published book by Springer-Verlag in the series Springer Tracts in Modern Physics.

### December 2009

On November 17, 2009 Professor Paul Hacking gave a talk in the Algebraic Geometry Seminar at Princeton University. The talk was entitled *Smoothing Surface Singularities via Mirror Symmetry.* His National Science Foundation proposal entitled *Exceptional Vector Bundles and Degenerations of Surfaces* was funded for the period 9/1/09-8/31/12 (NSF DMS-0968824).

On November 5, 2009 Professor Daeyoung Kim gave a talk in the Machine Learning and Friends Lunch Series, Department of Computer Science, University of Massachusetts Amherst. The talk was entitled *Selection of Consistent Roots to the Likelihood Equation In Finite Mixtures of Location-Scale Distributions.* On October 6, 2009 he gave a talk in the Department of Community Health, Center for Statistical Sciences, Brown University. The talk was entitled *Likelihood-Based Confidence Sets and Empirical Identifiability in the Mixture Model.*

On October 13, 2009 Professor Eric Sommers gave a talk entitled *A Survey of Robinson-Schensted Algorithms in Types B/C and Their Connections to Lie theory* in the Algebra Seminar at the University of Connecticut. He gave the same talk in the Combinatorics Seminar at the University of Minnesota on November 6. While visiting the University of Minnesota, he also gave a colloquium talk entitled *Green Polynomials in Representation Theory and Combinatorics.* On November 16, he spoke at the University of Maryland on *Two Partially Ordered Sets Arising from Nilpotent Orbits.* Back in July, Eric gave two lectures on the *Geometry of Nilpotent Orbits* at the workshop *Computational Theory of Real Reductive Groups* at the University of Utah. Graduate student Garret Cahill attended the workshop, which focused on the ATLAS software for studying the structure of real reductive groups.

This year we celebrate the 160th anniversary of the discovery of 27 lines on a cubic surface by Arthur Cayley and George Salmon in 1849. Many people think that this discovery started modern algebraic geometry. For this reason the cubic surface with its 27 lines is an emblem of the Algebraic Geometry research group in our department; see http://www.math.umass.edu/Research/respage.html?group=Algebraic Geometry. You can read more about cubic surfaces at http://www-history.mcs.st-andrews.ac.uk/HistTopics/Cubic_surfaces.html. In order to celebrate this discovery, Professor Jenia Tevelev gave a series of lectures to various audiences during October and November 2009.

\t1. A talk in the Math Club in our department entitled *Pretty Pictures, or How to Catch a Butterfly* on October 19;

\t2. The "What Is ...?" Graduate Seminar in our department entitled *What Is a Moduli Space?* on October 22;

\t3. A talk in AGNES at the State University of New York at Stony Brook entitled *On the Cone of Effective Divisors of M_{0,n}* on October 31. AGNES (Algebraic Geometry Northeastern Series) is a new series of biannual weekend workshops in algebraic geometry. One of its goals is to introduce graduate students to a broad spectrum of current research in algebraic geometry. The organizing committee of AGNES includes Professor Paul Hacking and Professor Jenia Tevelev. The first workshop was held at SUNY Stony Brook during the period October 30 ÔøΩ November 1 and attracted over 80 participants. The second workshop will be held at the University of Massachusetts Amherst during the period April 10ÔøΩ11, 2010.

\t4. Two talks in the Algebraic Geometry Seminar in our department entitled *Reconstruction Problem in Mirror Symmetry* on November 6 and November 13.

\t5. A colloquium talk at the University of Arizona in Tucson entitled *Compact moduli Spaces of Algebraic Surfaces* on November 12;

\t6. A colloquium talk in our department entitled *Effective Divisors on Moduli Spaces of Curves* on November 19.

### November 2009

In June 2009 the National Science Foundation awarded Professor Richard S. Ellis a Research Opportunity Award for Peter T. Otto as a supplement to his current NSF grant. Peter is a former graduate student of Richard's and a current collaborator, who has worked with him on five papers. Peter is an assistant professor in the Department of Mathematics at Willamette University, an undergraduate institution in Salem, OR. The aim of the Research Opportunity Award is to support research in undergraduate institutions such as Willamette University. In addition, on October 29, 2009 Richard gave a talk at the Statistics and Probability Seminar in the Department of Mathematics and Statistics at Boston University. His talk was an introduction to the theory of large deviations entitled *What Is the Most Likely Way for an Unlikely Event To Happen?*

The Fall 2009 Arbeitsgemeinschaft was held during the period October 4-10 at the Mathematisches Forschungsinstitut Oberwolfach (MFO), focusing on the topic of minimal surfaces. Professor Rob Kusner gave the opening lecture on *Conjugate Constructions, Jenkins-Serrin Graphs and the Scherk Surfaces* and Professor William Meeks, a co-organizer of the workshop, led a problem session during the second evening. At the end of the workshop the participants selected the topic, coarse geometry and geometric group theory, and the potential organizers for the Spring 2010 Arbeitsgemeinschaft at MFO.

Professor Emeritus Floyd Williams gave a 40-minute invited talk at the AMS special session on Mathematical Aspects of Spectral Problems Related to Physics, held at Baylor University in Waco, Texas during the period October 16-18, 2009. The title of his talk was *Casimir Energy and Local Zeta Function for Higher Rank Symmetric Spaces.* Floyd's student, Jennie D'Ambroise, give a 20-minute invited talk at this AMS special session. The title of her talk was *Elliptic Functions in Cosmology.*

### October 2009

Professor Richard S. Ellis has signed a publication contract for his book, *Blinding Pain, Simple Truth: Changing Your Life Through Buddhist Meditation*. It will be published by Rainbow Books, an independent publisher founded in 1979. The book describes how Buddhist teachings and daily meditation can empower readers to heal the suffering caused by physical and emotional pain. As the book shows, Buddhist teachings also provide a new lens for reading the Bible, yielding fresh insights that speak in surprisingly relevant ways to spiritual seekers and to those who want to heal themselves. Further information about the book is available online http://www.math.umass.edu/~rsellis/Blinding-Pain-Simple-Truth.html>.

Professor Panos Kevrekidis had a busy summer. He visited the University of Heidelberg during the months of July and August, having been granted a two-year extension of his research fellowship from the Alexander von Humboldt Foundation (for summers 2009 and 2010). During this time frame, Panos also visited and presented his recent work on discrete nonlinear Schr√∂dinger equations at the University of Munich. Together with the nonlinear dynamics group at the University of Seville, he co-organized the workshop entitled *LENCOS: Localized Excitations in Nonlinear Complex Systems.* In the workshop, Panos presented his work on dark solitons and their interactions in connection with recent experiments on Bose-Einstein condensates. Finally, during the month of July, his second book entitled The Discrete Nonlinear Schr√∂dinger Equation: Mathematical Analysis, Numerical Computations and Physical Perspectives was published by Springer, and the special volume of Physica D on *Nonlinear Phenomena on Degenerate Quantum Gases,* which he co-edited, was published by Elsevier.

On September 14, 2009, Professor Rob Kusner kicked off the fall 2009 Temple University colloquium series with a talk entitled *Tiling Surfaces, Flat Metrics, and Abel's Theorem.* The following day he lectured in their Contact and Hyperbolic Geometry Seminar on *Moduli Spaces of CP^1 Structures and CMC Surfaces.*

Professor William Meeks reports on the following activities that took place since June 2009.

1. He gave talks at two geometry conferences in Spain, one in Nerja and the other in Granada.

2. He gave two talks in the geometry seminar at the Korean Institute for Advance Study, one in June and the other in July.

3. He gave one of the plenary talks at the International Conference in Geometry in Rio de Janeiro, Brazil in August.

4. In September he gave a talk in the geometry seminar at the University of Granada and a colloquium at the University of Bologna.

5. In the first week of October he gave a talk at a workshop at Oberwolfach, Germany. He is also one of the two organizers of this workshop.

Professor John Staudenmayer and his collaborators Professors Freedson and Braun in the Department of Kinesiology at UMass Amherst were awarded a $950,000 NIH grant entitled *Advancing Physical Activity Measurement Using Pattern Recognition Techniques.* This grant was funded through the NIH *Challenge Grant* stimulus-funding mechanism. NIH received about 21,000 applications for these grants, and only 200 were funded.

### September 2009

On June 18, 2009 Professor Brian Burrell presented Grand Rounds in Neurology at Massachusetts General Hospital. The title of the talk was *Brainspotting: What Good is a Collection of Famous Brains?* The talk was given at the famous Ether Dome, which is the operating theater in which an anesthetic was first used during a surgery. He also wrote a short piece for Forbes.com entitled *Words We Live By: Some aphorisms evolve with changing times, but more often get stuck in time.* The piece is available on their website as part of a special edition. The URL is http://www.forbes.com/2009/08/12/brian-burrell-quotations-opinions-burrell.html.

On June 30, 2009 Professor Richard S. Ellis gave an invited talk in the Department of Mathematics at University of Rome. His talk was an introduction to the theory of large deviations and was entitled *What Is the Most Likely Way for an Unlikely Event To Happen?*

Professor Markos Katsoulakis reports on the following activities during the summer of 2009.

\t1. Markos received a $325,000 grant from the U.S. Department of Energy for a proposal entitled *Multiscale Mathematics for Biomass Conversion to Renewable Hydrogen.*

\t2. Markos was an invited speaker at the ESPRC Symposium Capstone Conference held at Warwick University and Warwick Mathematics Institute in the United Kingdom, during the period June 30 - July 3, 2009. The title of his talk was *Hierarchical and Multi-Level Coarse-Graining Methods.*

\t3. Markos was an invited lecturer at the Summer School and Conference on Kinetics and Statistical Methods for Complex Particle Systems. This two-week summer program was held during July 2009 in Lisbon, Portugal. The week of July 13-17 featured a summer school for graduate students and postdocs at which Markos and four other people spoke. During the week of July 20-24 a workshop took place featuring lectures on recent progress in this field. Markos's four talks are available at the conference website http://www.utaustinportugal.org/Events.aspx?event=237.

\t4. Markos was an invited speaker at the Conference on Mathematical Challenges Motivated by Multi-Phase Materials: Analytical, Stochastic and Discrete Aspects, which was held in Anogeia, Crete, Greece during the period June 21-26, 2009. The title of his talk was *Hierarchical Pattern Discovery in Many-Body Complex Stochastic Systems.*

\t5. Markos was an invited panel moderator at the Opening Workshop of the Stochastic Dynamics Program for 2009-2010 at SAMSI during the period August 30 - September 2, 2009.

Professor Daeyoung Kim organized a special session for contributed papers on the Mixture Model and Its Applications at the 1st IMS Asia Pacific Rim Meeting, which was held at Seoul National University in Seoul, South Korea during the period June 28 - July 1, 2009. He also gave a talk in this session, entitled *Likelihood Confidence Sets and Empirical Identifiability in the Mixture Model.* On August 2, 2009 Daeyoung gave a contributed talk at the Joint Statistical Meeting in Washington, D.C. The title of the talk was *Data-based Assessment of Asymptotic Label Identifiability in Mixture Models.*

During June 2009, visiting professor Karsten Grosse-Brauckmann and Professor Rob Kusner, who was his host here during the past year, lectured on their joint work concerning constant mean curvature surfaces at Lehigh's Journal of Differential Geometry conference. During August, Rob participated at the workshop on Symplectic and Contact Topology at MSRI in Berkeley and also visited Stanford University and nearby Google.

Professor Michael Lavine was awarded a grant by the National Institutes of Health of approximately $800,000. The purpose of the grant is to study statistical aspects of neocortical hemodynamics during epileptic activity in primates and humans. The money will allow the department to hire a postdoc for five years.

Professor Franz Pedit gave an invited talk entitled *Bending CMC Cylinders* at A Harmonic Map Fest honoring J. C. Wood and taking place in Cagliari, Italy during the period September 7-10, 2009. He gave a second invited talk with the same title at the workshop on Variational Problems of Higher Order in Geometry, which took place at the Konrad-Zuse-Zentrum fuer Informationstechnik Berlin during the period September 16-18, 2009.

During the period August 24-28, 2009 Professor Jenia Tevelev gave a three-lecture minicourse entitled *Tropical Elimination Theory* at the Introductory Workshop of the Tropical Algebraic Geometry Program at MSRI in Berkeley. His paper entitled *Equations for M_{0,n},* written jointly with Sean Keel, was published by the International Journal of Mathematics, volume 20, number 9 (2009), 1-26. His paper *Stable Pair, Tropical, and Log Canonical Compact Moduli of Del Pezzo Surfaces,* written jointly with Paul Hacking and Sean Keel, was published by Inventiones mathematicae, volume 178, number 1 (2009), 173-228.

On August 18, 2009 Visiting Assistant Professor Giancarlo Urzua gave an invited talk in the workshop on Algebraic Surfaces and Related Topics, held at the Pohang Mathematics Institute in Pohang, Korea. The webpage for the conference is http://math.postech.ac.kr/~wlog/workshop/.

Professor Robin Young was an invited participant in the IMA's summer program, Nonlinear Conservation Laws and Applications, held during the period July 13-31, 2009 in Minneapolis, MN. He presented two posters on his recent work on *Strong Wave Interactions and Vacuums* and his joint work on *Periodic Solutions of the Euler Equations* with Blake Temple. Also, the National Science Foundation awarded Robin a three-year, $125,000 grant entitled *Periodic and Large Amplitude Solutions for the Compressible Euler Equations.*

Professor HongKun Zhang was awarded a National Science Foundation grant. The grant starts in August 2009 and ends in July 2012.