# Faculty News Briefs

### April 2008

On March 16, 2008 Professor Tom Braden gave a talk at the AMS meeting at New York University in a special session on algebraic combinatorial geometry. The talk was entitled *Hypertoric Varieties and Gale Duality.*

Professor Emeritus Ed Connors was appointed to a 3-year term on the Karl Menger Prize Committee. The committee will serve as the American Mathematical Society's special awards judges at this yearís Intel International Science and Engineering Fair being held in Atlanta during the period May 11ñ16, 2008.

A new book by Professor Emeritus Jim Humphreys will be published by the American Mathematical Society later this year in their series Graduate Studies in Mathematics. The title is Representations of Semisimple Lie Algebras in the BGG Category O; the upper case script letter O comes from the Russian word *osnovnoj* meaning basic or principal. BGG abbreviates the names of Joseph Bernstein, Israel Gelfand, and Sergei Gelfand.

Professors Rob Kusner and Franz Pedit and their former Ph.D. students Martin Kilian, Wayne Rossman, and Nick Schmitt, participated in a week-long meeting at Kloster Schˆntal in Germany's Odenwald during the first week of March 2008. Kilian, now a professor in Cork, Ireland, reported on his recent breakthrough on the Lawson conjecture, asserting that the Clifford torus is the only embedded minimal surface of genus 1 in the three-sphere. Rossman and Schmitt, now professors in Kobe, Japan, and T¸bingen, Germany, respectively, helped the attendees celebrate the 48th birthday of their former advisor at the meeting. As is well known, 48 is the order of the symmetry group for the cube, and so, in order to honor the occasion, Rob was given a small but perfect cubic crystal of sodium chloride.

### March 2008

On January 31, 2008 Visiting Assistant Professor Roman Fedorov gave a talk at the Boston University Geometry Seminar. The title was *Langlandís Transform and PainlevÈ Equations.*

During the week of February 18ñ25, 2008, Professor Rob Kusner visited the University of Georgia in Athens, where he collaborated and lectured on constant mean curvature surfaces.

Professor William Meeks is on sabbatical during the spring semester of 2008. As part of his sabbatical he is traveling overseas to give talks and to do joint research projects. At the beginning of the year he spent one month in Spain at the University of Granada to do joint research with Professors Ferrer and Martin and with Professors Perez and Ros. While there he solved one well known conjecture together with Perez and Ros called the *Stable Limit Leaf Conjecture.* In less than a month, Professor Meeks wrote up the paper, submitted it to the Journal of Differential Geometry for review, and the journal accepted it for publication. While there, he also gave a talk in the geometry seminar. He plans to return to Granada in March for about one month and then again at the end of May for about a month. During his May visit to Europe he will attend a geometry conference in Rome. Professor Meeks also reports on the following invitations.

In March he will be going to McGill University in Montreal in order to lecture on his recent paper, *Dynamics Theorem for CMC Surfaces,* which is based on joint research with Giuseppe Tinaglia.

At the beginning of May, he plans to attend and give a plenary talk at the Triannual Journal of Geometry Conference at Harvard University. He will then leave for a two-week visit to Korea, where he will give a series of eight research talks to geometers.

At the end of August, he will give a plenary talk at a conference on geometry and physics at Harvard University as part of the 60th birthday celebration in honor of his friend, Professor S.T. Yau of Harvard University.

Finally, in November he will be giving two plenary lectures on his research at the annual *Current Developments in Mathematics Conference* at MIT-Harvard. His invitation is considered to be a special honor. The speakers invited to this conference will speak on the most interesting recent developments in mathematics.

On February 15, 2008 Visiting Assistant Professor Ralf Schiffler gave a talk at the Colloquium on Modules and Related Topics at the UniversitÈ du QuÈbec ‡ MontrÈal. The title of his talk was *Sur la Structure Combinatoire des AlgÈbres AmassÈes.*

A paper entitled *Density Estimation in the Presence of Heteroskedastic Measurement Error* by Professors John Staudenmayer, John Buonaccorsi, and David Ruppert of Cornell University is to appear in the Journal of the American Statistical Association.

### February 2008

Professor John Buonaccorsi was a guest researcher at the Section for Biostatistics at the University of Oslo Medical School for much of January 2008, with support provided by the Norwegian Research Council. He continued his ongoing collaboration with colleagues on statistical methods for handling measurement error and misclassification in epidemiologic studies. He also presented a talk on *Measurement Error in Time Series with Applications to Population Dynamics* through the Centre for Research-based Statistical Innovation at the University of Oslo.

Professor Panos Kevrekidis has published his first book, which appeared in Springer-Verlagís Atomic, Optical, and Plasma Series. Co-edited by Panosís close collaborators Dimitri Frantzeskakis and Ricardo Carretero-Gonz·lez, the book is entitled Emergent Nonlinear Phenomena in Bose-Einstein Condensates. The book features a series of theoretical and experimental review-style chapters by experts on different nonlinear phenomena arising in the field of Bose-Einstein Condensates, which is a major thrust of Panosís work. The preface was written by Professor Wolfgang Ketterle of MIT, who won the Nobel Prize.

During January 2008 Professor Rob Kusner lectured on *Nondegeneracy of Constant Mean Curvature Surfaces* at the University of Pennsylvania, where he is spending his sabbatical this spring. Robís collaborator and former NSF postdoctoral fellow at UMass, Jason Cantarella (also on sabbatical at Penn now), also spoke about their joint work *Minimizing the Length of Curves with Curvature Bounded Above.*

### January 2008

We are happy to welcome Professor Michael Lavine to our department. His official starting date is January 27, 2008.

Visiting Assistant Professor Ralf Schiffler gave a colloquium talk at Kansas State University on December 3, 2007. The title of his talk was *Quiver Representations: Basic Facts and Some Recent Developments.*

During December 2007 Professor Jenia Tevelev gave talks at the Algebra, Geometry, and Physics Seminar at SUNY Stony Brook and at the Tropical Geometry Workshop in Oberwolfach, Germany. The talks were entitled *Tropical Compactifications of Subvarieties of Tori.* Jenia was also appointed an editor of the journal Transformation Groups.

### December 2007

On November 26, 2007, Professor Tom Braden gave a talk entitled *Category O for Hyperplane Arrangements* in the Geometry, Algebra, Singularities, and Combinatorics Seminar at Northeastern University.

During November, Visiting Assistant Professor Roman Fedorov gave a talk entitled "Deformations of Algebro-Geometric Solutions of KadomtsevñPetviashvili Equations and Frobenius Manifolds at the joint Math-Physics Seminar at the University of Pennsylvania.

During the period November 18ñ20, 2007, Professor Hans Johnston attended the Division of Fluid Dynamics meeting of the 60th annual American Physical Society meeting in Salt Lake City. At the meeting he participated in the following three activities: he gave a talk entitled *A Spectral Collocation Method for 2D Incompressible Fluids in Vorticity Formulation*; along with Charles Doering, he contributed a video to the Video Gallery of Fluid Motion entitled *Rayleigh-Benard Convection with Imposed Heat Flux*; he chaired a session entitled *Computational Fluid Dynamics.* His talk was presented at this session.

Professor Panos Kevrekidis had a busy fall. During October, Panos gave the Mathematics Colloquium at the University of Vermont on October 4, and then in the third week of October, he was one of the invited speakers at the workshop on Hamiltonian Lattice Dynamical Systems, which took place in Leiden, Netherlands. Panos was also invited to be a Visiting Fellow at the Research Excellence Centre on Optical Communications and Quantum Atom Optics at the Australian National University in Canberra, Australia, where he spent two weeks and presented an invited seminar. Finally, Panos was recently awarded a Humboldt Research Fellowship and will be spending his sabbatical from March to July 2008 at the University of Heidelberg in Germany.

On November 19, 2007, Visiting Assistant Professor Ralf Schiffler gave a talk entitled *Cluster-tilted Algebras* in the Geometry, Algebra, Singularities, and Combinatorics seminar at Northeastern University.

On November 7, 2007 Professor Jenia Tevelev gave a talk entitled *Tropical Compactifications of Subvarieties of Tori* in the Algebraic Geometry Seminar at the University of Michigan. On November 16 he gave a talk entitled "Elimination Theory for Tropical Varieties" in the Mathematics Colloquium at Cleveland State University.