# Faculty News Briefs

### April 2010

On March 5, 2010 Professor John Buonaccorsi's new book, "Measurement Error: Models, Methods and Applications", was published by Chapman and Hall in their Interdisciplinary Statistics Series. From March through May, Buonaccorsi has been a Visiting Professor in the Department of Biostatistics (Medical School) and CEES (Center for Ecological and Evolutionary Synthesis) at the University of Oslo, Norway. He presented a CEES seminar on "Observation Error in Fitting Population Dynamic Models," and he taught a one-week course on "Observation/Measurement Error in Analyzing Biological Data."

On April 20 Professor Richard S. Ellis gave a talk in the Department of Mathematics at the University of Athens in Athens, Greece, entitled *From Large Deviations to Statistical Mechanics: What Is the Most Likely Way for an Unlikely Event To Happen?* On April 26 he gave a colloquium talk on the same topic in the Department of Mathematics at the Technion in Haifa, Israel.

### March 2010

From March 15th to 19th Associate Professor Tom Braden participated in a workshop at American Institute of Mathematics on localization techniques in equivariant cohomology. He gave a talk entitled "Introduction to GKM theory" and led an afternoon session on intersection cohomology.

Professor Panos Kevrekidis attended the American Physical Society March Meeting in Portland, and then was invited to participate on the Frontiers of Nonlinear Waves Conference in Tucson, AZ in honor of V.E. Zakharov's 70th birthday At both meetings, Kevrekidis presented his recent work on dark solitons and vortices in Bose-Einstein condensates combining theory, computations and experiments.

Assistant Professor HongKun Zhang gave the Geometry Seminar at the Department of Mathematics at Washington University St. Louis on March 26, speaking on: "Spectral gap for deterministic and random billiards." She was also invited to be one of the plenary speakers at Eastern Illinois University for "the Annual Geometry, Dynamics and Topology Day" on March 27.

Professor Michael Lavine and his students, Zhiyi Sun and Yanbo Wang, presented a poster on spatial analysis of carbon dioxide flux on March 16 at the Twentieth Annual Harvard Forest Ecology Symposium.

On February 15, Professor Richard S. Ellis gave a colloquium talk in the Department of Mathematics at Oregon State University in Corvallis. His talk was an introduction to the theory of large deviations entitled "From Large Deviations to Statistical Mechanics: What Is the Most Likely Way for an Unlikely Event To Happen?" On February 18 Richard gave a talk at the University Convocation at Willamette University in Salem in which he discussed how Buddhist meditation can help alleviate the suffering caused by physical and emotional pain. He has a forthcoming book on this topic: "Blinding Pain, Simple Truth: Changing Your Life Through Buddhist Meditation."

### February 2010

Prof. Panos Kevrekidis delivered the Mathematics Colloquium at Drexel on January 14, as well as the Physics Colloquium at Amherst College on February 11. In these talks, Panos discussed the recent work of his group on granular crystals, nonlinear optics of layered media and multi-component Bose-Einstein condensates.

On February 3, Prof. John Staudenmayer gave a talk "Novel analytical techniques for physical activity assessment" at the National Cancer Institute National Institute of Health in Bethesda, MD.

### 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.