# Faculty News Briefs

### January 2015

Covering the period June 2014 – January 2015

In July 2014 Professor Tom Braden attended a workshop in geometric representation theory at RIMS in Kyoto, Japan. He gave a three-part minicourse on “Recent Developments in Modular Sheaf Theory” and a research talk titled “Ringel Duality and Perverse Sheaves on Hypertoric Varieties.”

Senior Lecturer Brian Burrell and Dr. Allan Ropper wrote a book titled *Reaching Down the Rabbit Hole*, which was published in 2014. The UK edition of the book was the BBC Radio4 book of the week during the week of January 12, 2015. An actor read 15-minute excerpts from the book each weekday morning over BBC 4 radio. During that week the book stayed in the top 50 on Amazon.uk, and on Sunday, January 25, the book hit the top ten list of the *Times of London* for non-fiction at #9.

In August 2014 Princeton University Press published a book titled *Hodge Theory* that Professor Eduardo Cattani edited together with Phillip Griffiths (Institute for Advanced Study), Fouad Elzein (Paris), and Le Dung Trang (Montpellier and ICTP). The book announcement can be viewed at http://press.princeton.edu/titles/10288.html.

In July 2014 Professor Matthew Dobson gave two talks. The first talk, titled “Algorithms for the Stochastic Simulation of Steady Nonequilibrium Flow,” was given at WWCM-ECCOMAS in Barcelona, Spain, and the second talk, titled “Generalized K-R Boundary Conditions for Steady Nonequilibrium Flow,” was given at PCMI in Park City, Utah.

The article by Professor Richard S. Ellis titled “Jewish Journeys: Decoding the Torah's Wisdom by Jewish Meditation” was published online by Jewish Currents <http://jewishcurrents.org/jewish-journeys-decoding-torahs-wisdom-buddhist-meditation-29011>. Richard wrote this article in conjunction with his appointment as an adjunct professor in the Department of Judaic and Near Eastern Studies at UMass Amherst.

Professor Panos Kevrekidis was honored by being elected a Fellow of the American Physical Society. Panos is cited for “fundamental contributions to the understanding of localized solutions, of their stability in nonlinear wave equations, and of their relevance to applications from atomic physics, nonlinear optics, and granular crystals.” Further information about this honor is available at http://www.umass.edu/newsoffice/article/two-umass-amherst-researchers-honored.

Professor Panos Kevrekidis had a busy summer. In late May 2014 he visited the University of Hamburg, giving an invited talk in the workshop on “Bose-Einstein Condensates in Waveguides: Curvature Meets Nonlinearity and Nonlocality.” He also visited the De Giorgi Center in Pisa, Italy, giving an invited lecture at the workshop on the “Stability of Solitary Waves.” Panos then visited collaborators at the University of Heidelberg in Germany during the month of July as well as collaborators at the University of Athens in Greece during August. In July Panos also participated in the AIMS Conference for Dynamical Systems in Madrid, Spain, and in August he participated in the SIAM Meeting on Nonlinear Waves and Coherent Structures in Cambridge, UK. Panos gave invited talks on his recent work on granular crystals at the conference in Madrid and on vortices in atomic condensates at the meeting in Cambridge. In Madrid he also co-organized, with Ricardo Carretero, a session on “Nonlinear Schrödinger Equations and Their Applications,” while in Cambridge he organized a session on “Novel Challenges in Atomic Gases: Bose-Einstein Condensates and Beyond.” During the academic year 2014–2015, Panos is visiting the Center for Nonlinear Studies of the Los Alamos National Laboratory in the capacity of the Stanislaw M. Ulam Distinguished Scholar. Prior to departing for his LANL post, in September Panos presented an Applied Mathematics Colloquium at the University of North Carolina and received the UMass Amherst Award for Outstanding Accomplishments in Research and Creative Activity at the 2014 Faculty Convocation.

During the second week of June 2014 Professor Rob Kusner visited colleagues at McGill University in Montreal, Canada, giving a two-hour lecture on June 13 titled “Linear Area Growth for CMC Surfaces in S^3.” Later in June and in July he was a research member of the IAS/PCMI program on Mathematics and Materials in Park City, Utah. Rob was invited to the Program on “Minimal Energy Point Sets, Lattices, and Designs” at the Erwin Schrödinger Institute in Vienna, Austria during the period October 12–18 in Vienna, Austria, where he spoke on “Coulomb Electrons on S^2 and the Möbius Energy of Hopf Links in R^3 and S^3.” He also gave a long seminar at Penn on November 11 and a colloquium at Lehigh on November 12 on the same topic. In addition Rob has been invited as a Research Professor for the spring 2016 Differential Geometry program at the Mathematical Sciences Research Institute in Berkeley. During January 2015 he began commuting back and forth to Brown University's Institute for Computational and Experimental Research in Mathematics to help organize its spring 2015 program on Phase Transitions and Emergent Properties.

Professor Andrea Nahmod was honored by being elected a Fellow of the American Mathematical Society in recognition of her “contributions to nonlinear Fourier analysis, harmonic analysis, and partial differential equations, as well as service to the mathematical community.” Further information about this honor is available at http://www.umass.edu/newsoffice/article/nahmod-named-fellow-american-mathematical.

Professor Michael Lavine reports on the following activities:

- He had two refereed publications accepted in the last half of 2014.
- Aaron Ellison, Michael Lavine, Peter Kerson, Audrey Barker Plotkin, and David Orwig, Building a Foundation: Land-Use History and Dendrochronology Reveal Temporal Dynamics of a
*Tsuga Canadensis*(Pinaceae) Forest,*Rhodora*116, No. 968. - Minji Park, David Reckhow, Michael Lavine, Erik Rosenfeldt, Benjamin Stanford, and Mi-Hyun Park, Multivariate Analyses for Monitoring EDCs and PPCPs in Lake Water,
*Water Environment Research*86, November.

- Aaron Ellison, Michael Lavine, Peter Kerson, Audrey Barker Plotkin, and David Orwig, Building a Foundation: Land-Use History and Dendrochronology Reveal Temporal Dynamics of a
- In the second half of 2014 he gave an invited talk titled “What is Bayesian Statistics and Why Everything Else is Wrong” in the Department of Mathematical Sciences at Worcester Polytechnic Institute in Worcester, MA.
- He wrote an article titled “Climate Change, Statistical Significance, and Science,” which comments on the improper use of statistics in a New York Times opinion piece. The article is posted at http://www.stats.org/climate-change-statistical-significance-and-science.

In September 2014 Professor Eric Sommers attended the workshop “Geometric Methods in Representation Theory” at Lancaster University in England, where he gave a talk titled “Exterior Powers of the Reflection Representation in Springer Theory.”

In July 2014 Professor Jenia Tevelev contributed several lectures to the summer school “Graduate Workshop on Moduli of Curves,” which was organized by Samuel Grushevsky, Robert Lazarsfeld, and Eduard Looijenga at the Simons Center for Geometry and Physics at Stony Brook University. The goal of the workshop was to introduce graduate students to the moduli theory of Riemann surfaces simultaneously from the viewpoints of algebraic geometry, topology, and Teichmüller theory. In September 2014 Jenia participated in a week-long conference “Tropicalization, Realization, and Algebraic-Tropical Correspondence” in Eilat, Israel. He delivered a talk “Non-Abelian and Spherical Tropicalization” based on his work and the work of his graduate student, Tassos Vogiannou.

### May 2014

Various department folk - including Professors Panos Kevrekidis, Rob Kusner, Andrea Nahmod and Floyd Williams - gave talks at the AMS Meeting in Albuquerque, New Mexico, April 5-6. Floyd gave a 40 minute talk entitled "Magnetic resolvent trace formula for 2d black hole vacua" in the "Topics in spectral geometry and global analysis" special session; Rob lectured on "Chirality for knots and fields" (after presenting a short video roasting "Physical Knots" special session honoree Jon Simon on his retirement); Panos spoke on "Dynamics of Nonlinear Waves in Granular Crystals" in his special session (going on to lecture in Los Alamos later that week); and Andrea talked about "Bilinear estimates... for the Ward system" in the "Harmonic Analysis" special session.

On April 23, Professor Rob Kusner was invited by the students of Commonwealth College to lead a "Faculty Chat" about "Bubbles" - about 40 students dropped in, enjoying pizza and chicken wings while performing bubble experiments and discussing the geometry of bubble surfaces with Rob.

Professor and Department Head Michael Lavine gave a talk on "Kernel Intensity Estimation of 2-Dimensional Spatial Poisson Point Processes from k-Tree Sampling" to the Virginia Tech statistics seminar April 10.

G. D. Birkhoff Professor William Meeks has a major paper on "Properly embedded minimal planar domains" (written with his Granada collaborators Joaquin Perez and Antonio Ros) appearing in the Annals of Mathematics this month. This is the sixth paper Bill has published in the Annals - arguably the premier journal in all of mathematics - over his distinguished career. Bill also gave a three-lecture mini-course on "Curvature and radius estimates for embedded CMC surfaces" at the March 2014 International Geometry Conference in Maceio, Brazil.

Professor Jenia Tevelev reports the following activities this semester: On January 30, his talk "Mori nightmare spaces" was delivered at Yale. From February 24 to 28 he gave two talks at the "Workshop on birational geometry and stability of moduli stacks and spaces of curves" held at the Vietnam Institute for Advanced Study in Mathematics in Hanoi, Vietnam. Jenia spoke on "Birational geometry of moduli of stable rational curves" at several venues: Michigan (March 19), Princeton (April 22) and Harvard (April 29). On April 26, he co-organized and led a panel discussion on undergraduate research with Sam Payne (Yale) and Jessica Sidman (Mt Holyoke)at the AGNES (Algebraic Geometry Northeastern Series) conference in Stony Brook. This professional development event was intended for - and attended by - all 170 conference participants: graduate students, postdocs and faculty.

### April 2014

During March 2014 Professor Richard S. Ellis gave two talks in the Department of Mathematics at the University of Illinois in Urbana-Champaign. On March 17 he gave a special presentation titled "Healing the Stress of Academic Life." On March 18 he gave a colloquium lecture titled "From Large Deviations to Statistical Mechanics: What Is the Most Likely Way for an Unlikely Event To Happen?"

On March 26 Professor Michael Lavine delivered the Sigma Xi talk at Smith College, "Before You Analyze, Know Y" about ensuring that statistical analyses match the data they're trying to represent.

For 30 hours over the weekend of March 28-30, about 70 Five Colleges undergraduate students participated in DataFest, wherein small teams compete to address a real-world problem supported by an interesting data set. DataFest is held at several locations around the country; the Five College event was held in LGRT 1634 and was organized by Andrew Bray.

### March 2014

On 22 February 2014, Professor Rob Kusner lectured on "Chirality for Curves and More" at UTAustin. The following week he visited the Isaac Newton Institute in Cambridge, England, for their Foams and Minimal Surfaces workshop where he collaborated with colleagues and gave a plenary talk about "Materials and Meromorphic Differentials" on 25 February 2014.

Professor Michael Lavine delivered a talk 26 February 2014 at the Institute for Social Sciences Research at UMassAmherst -- "Before You Analyze, Know Y" -- on why it is dangerous to choose a statistical analysis without seeing the data.

Lecturers Jeff Beaulieu, Catherine Benincasa, Adena Calden, Erica Farelli, John Gambino, and Jinguo Lian each won the Residential First Year Experience Award. To receive this award, instructors must be nominated by a first-year student. The award recognizes instructors who inspire students to learn, who host interesting and motivating lectures, who go above and beyond the call of duty to support first-year students, help them adjust to college, challenge them to reach their full potential, and more.

### February 2014

On 6 January 2014, Visiting Assistant Professor Christopher Chong spoke on "Localization in Nonlinear Coupled Oscillators" at the ETH Zurich, Switzerland in a seminar within the Department of Mechanical and Process Engineering.

A recent major DOE grant awarded to Professors Markos Katsoulakis and Luc Rey-Bellet has been highlighted by the University News Office.

The research, service and teaching of Professor Panos Kevrekidis were recognized with a number of honors.

Panos has been awarded the biennial J.D. Crawford prize from the Activity Group on Dynamical Systems of the Society for Industrial and Applied Mathematics. He has also been honored with the Aristides F. Pallas award of the Academy of Athens, Greece for his work "Nonlinear Waves in Lattices: Past, Present, Future." As part of his service to the Dynamical Systems community, Panos has been selected as one of the two Co-Chairs for the major biennial conference in the field, scheduled to take place at Snowbird in May 2015.

Panos also received an IRSES grant from the European Union, jointly with the universities in Thessaloniki, Greece, and Oldenburg, Germany, allowing several researchers from Greece and Germany to visit our Department over the next 4 years. This grant is supporting the research of the first postdoctoral scholar, Dr. Stathis Charalampidis from Thessaloniki, from November 2013 until November 2014.

Finally, Panos recently garnered the Outstanding Teacher Award of the College of Natural Sciences.

Professor Michael Lavine gave an invited seminar 10 December 2013 at the University of Waterloo's Department of Statistics and Actuarial Science titled "On Rigorous Specification of ICAR Models."

On 16 December 2013, Professor Ivan Mirkovic gave a talk at the Moscow conference on "Representation Theory and applications to Combinatorics, Geometry and Quantum Physics" dedicated to the 60th Birthday of Boris Feigin. Earlier he lectured twice in Stony Brook: a colloquium on "Loop Grassmannians" (7 May 2013) and at the Simons Center "Quiver Varieties" workshop (15 October 2013).

Professor Alexei Oblomkov has just been awarded an Early Career Award by the NSF - congratulations Alex! He also visited Professor Motohico Mulase at the University of California Davis the last week in January. Alex delivered three lectures while there: "Plane curve singularities, knot homology and the Hilbert scheme of points in the plane" for their Topology Seminar; "Khovanov-Rozansky homology" for their Graduate Seminar; and "Plane curve singularities and the topological vertex" for their String Theory Seminar.

Each year Professor Jenia Tevelev supervises an REU in his research area, Algebraic Geometry. In 2013, he worked with Morgan Opie, who wrote a well-received paper "Extremal divisors on moduli spaces of rational curves with marked points" based on this REU project; she is now expanding it into an Honors thesis. Morgan presented a poster on this at the Young Mathematicians Conference at Ohio State University and at the Boston University AGNES (Algebraic Geometry Northeastern Series) Conference. She was also invited to give lectures at seminars and research conferences at the University of Massachusetts, University of Georgia, and University of Illinois at Chicago. For her achievements in academics and research, Opie has been recognized both on campus and nationally. She is the runner up for the 2014 Alice T. Schafer Prize, a national prize for excellence in mathematics by an undergraduate woman, awarded at the January 2014 joint meeting of the American Mathematical Society and the Mathematical Association of America. Opie is also one of four students selected to receive the 2013 UMass Amherst Rising Researcher award. Morgan has recently received a very prestigious Churchill scholarship which funds a year of postgraduate study at the University of Cambridge in England. Worth about $50,000, the scholarship covers a year of tuition, fees, living expenses and travel. Morgan was also admitted to top graduate schools in the United States (Harvard, MIT, Princeton, Yale, Brown,...).

In Fall 2013, Professor Jenia Tevelev spent three weeks visiting a former UMass postdoc, Professor Giancarlo Urzua, at Pontificia Universidad Catolica de Chile; Jenia delivered a colloquium talk there. Over the next three weeks he lectured twice at Ohio State University and visited another former UMass postdoc, Professor Ana-Maria Castravet. Jenia then spent two months at the University of Texas in Austin visiting Professor Sean Keel, Jenia's postdoctal mentor. Tevelev gave two talks there plus another at the University of Texas A&M, where he visited Professors JM Landsberg and Frank Sottile, a former UMass faculty member, who sends his regards.

In Austin, Jenia enjoyed conversations with UMass alum Nicky Reyes, who is now a graduate student at UT; Jenia supervised an REU with Nicky in Winter 2012. Tevelev and Castravet recently published a paper "Hypertrees, Projections, and Moduli of Stable Rational Curves" in Crelle's Journal which contains some results obtained by UMass alum Nate Harman when he was working on an REU project with Jenia in Summer 2011; Nate is now a graduate student at MIT.

Jenia Tevelev is also the recipient of NSF grant DMS-1303415 "Moduli Spaces of Curves and Surfaces."

On 14 January 2014, Visiting Assistant Professor Pengfei Zhang gave an invited talk titled Hyperbolicity of some generalized lemon billiards in the Northwestern University Dynamical Systems Seminar.