# Faculty News Briefs

### December 2013

Professor Erin Conlon gave an invited seminar at UMass Medical School in the Department of Quantitative Health Sciences on December 3, 2013. The title of her talk was "Bayesian Meta-Analysis Models for Gene Expression Studies".

Professor Franz Pedit visited Rice University the week of November 12-16, 2013, to work with Mike Wolf on superminimal surfaces, opers, representation varieties and Higgs bundles. While there, Franz delivered two lectures: a geometry seminar titled "Constrained Willmore surfaces: theory and experiments," and a colloquium on "Constant mean curvature surfaces: an integrable perspective."

Professor HongKun Zhang visited CIRM, Marseille, France, the week of December 1-7, 2013, where she was a keynote speaker at an international conference on Hyperbolicity and Dimension. She also gave a talk on "Lower bound for decay rates of correlations of nonuniformly hyperbolic billiards" while at the conference.

News Briefs will be on Winter Break till February 2014. In the meantime, have a wonderfully warm winter solstice and a perfectly pleasant perihelion!

### November 2013

On October 16th, Visiting Assistant Professor Christopher Chong spoke on "Solitary Waves of Discrete Nonlinear Schrodinger Equations" at the University of Massachusetts, Boston, Physics Colloquium.

Professors R. Inanc Baykur and Weimin Chen, together with Professor Daniel Ruberman from Brandeis University, organized a 2-day workshop "Group Actions on Smooth 4-Manifolds" at UMass Amherst, between October 25-26, 2013. The workshop brought together experts and active researchers in the field. Several graduate students from Brandeis and UMass participated in the event. The program neatly consisted of 2 talks by leading experts, 2 by young researchers, and 2 by recent PhDs, topped with 2 discussion sessions on open problems. For more details, please see the Group Actions workshop website.

On October 19, 2013, Professor HongKun Zhang, jointly with Renato Feres and Timothy Chumley, organized a Special Session on "Statistical Properties of Dynamical Systems" at the AMS sectional meeting at Washington University in St. Louis. HongKun also gave a talk "Optimal bound for decay of correlations of nonuniformly hyperbolic systems" at this meeting. She is the PI on a recently-submitted NSF-FRG proposal "Stochastic perspectives in dynamics: fundamental problems and novel applications" with a total budget of $1,095,229 and collaborators from 5 other institutions in the US. UMass is the lead institution, and visiting assistant professor Pengfei Zhang is serving as a Co-PI. Our statistics group hosted the University of Connecticut statistics department on Wednesday October 16. Xiaojing Wang from UConn delivered a seminar on "Shape constrained functions and Gaussian processes." ### October 2013 On 27 September 2013, Professor Franz Pedit gave a talk titled "Constrained Willmore surfaces: theory and experiments" at the Differential Geometry Workshop, Aarhus University, Denmark. Emeritus Professor Floyd Williams was appointed to the 4-member Scientific Committee for the Third International Satellite Conference in Mathematical Methods in Physics, to be held in Londrina-PR, Brazil, 21-26 October 2013. This year's Satellite Conference will focus on spectral theory, group theory, differential and algebraic topology, with applications to topological field theory, quantum gravity, strings and cosmology, and will feature 11 international speakers. Although Professor Williams, an AMS Fellow, will not lecture at this conference, he has spoken several times at similar conferences in Brazil over the past 15 years. ### September 2013 Professor John Buonaccorsi co-taught a week-long course on Measurement Error as part of the 2013 Second German Collaborative Summer School in Epidemiology held at the University of Greifswald. Founded in 1456, Greifswald is the second oldest university in northern Europe. On May 20, 2013 Adena Calden, a Senior Lecturer in our department, was invited by OIT to be on a panel regarding "Flipping the Classroom." Along with four colleagues she spoke to other faculty regarding the challenges and rewards of this model. On June 12 Adena was awarded a$12,000 community grant from the Northampton Education Foundation to create an engineering program for Leeds Elementary and Bridge Street School in Northampton. During the summer she helped train 20 teachers on Lego Robotics.

Professor Weimin Chen had a very busy summer. He spent eight weeks as a visitor at the Institute of Mathematics and Interdisciplinary Sciences in Beijing, China, and was a co-organizer of an FRG conference: Workshop and Conference on the Topology and Invariants of Smooth 4-manifolds at the University of Minnesota during the period July 31 - August 10. In addition Weimin delivered invited talks or mini-courses for graduate students at the following venues:

1. MPIM-Bonn workshop: Geometry and Topology of Smooth 4-manifolds in Bonn, Germany.

2. Workshop on Algebraic Topology at Capital Normal University in Beijing, China.

3. International Conference on Algebraic and Geometric Topology at the Chern Institute in China.

4. Colloquium at the Institute of Mathematics, Academia Sinica in Beijing, China.

5. FRG Conference: Topology and Invariants of Smooth 4-Manifolds at the University of Minnesota; mini-course speaker: "Group Actions on 4-Manifolds."

6. Mini-course: Group Actions on 4-Manifolds at Capital Normal University in Beijing, China.

Finally, Weimin's first Ph.D. student, Daniel Herr, had a successful thesis defense in August. Dan will be a Visiting Assistant Professor at Wheaton College starting in the Fall of 2013.

On June 11, 2013 Professor Matthew Dobson gave a talk at SIAM MS13 in Philadelphia on "Long-Time Simulation of Steady Nonequilibrium Flow." In July he gave two talks at USNCCM in Raleigh on "Long-Time Simulation of Steady Non-Equilibrium Flow" and on "There Is No Pointwise Consistent Quasicontinuum Scheme." On August 19 at the CEMRACS workshop in Marseille, France he gave a talk on "Algorithms for Long-Time Simulation of Nonequilibrium Molecular Dynamics." Finally Matthew's paper "Derivation of Langevin Dynamics in a Nonzero Background Flow Field," co-authored with Frederic Legoll, Tony Lelievre, and Gabriel Stoltz, was published in M2AN and chosen as a highlight article.

On August 22, 2013 Professor Richard S. Ellis gave a talk in the Center for Nonlinear Analysis Seminar, Department of Mathematical Sciences, Carnegie Mellon University in Pittsburgh, PA. The talk was titled "From Large Deviations to Statistical Mechanics: What Is the Most Likely Way for an Unlikely Event To Happen?" His mindfulness approach to chronic pain, which is the subject of his book Blinding Pain, Simple Truth: Changing Your Life Through Buddhist Meditation, was discussed on page 10 of the article "Tapping the Power of Mindfulness" by Maureen Salamon in H2U-Health to You magazine, Summer 2013, pages 8-10.

Professors Markos Katsoulakis and Luc Rey-Bellet were awarded a multi-institution grant by the U.S. Department of Energy (DOE) with the title "Mathematical Foundations for Uncertainty Quantification in Materials Design." The total amount for the three participating institutions (University of Massachusetts Amherst, University of Delaware, and Brown University) is \$2.3 million. The PIs are Markos Katsoulakis and Luc Rey-Bellet (UMass), Petr Plechac and Dion Vlachos (UDel), and Paul Dupuis (Brown). The grant was awarded by the DOE Office of Advanced Scientific Computing Research, which is the mathematical sciences division of DOE, and focuses on developing and deploying novel mathematical, statistical, and high performance computational methods for the rational design of materials for energy research. The grant is funded through a DOE 2013 call for "Uncertainty Quantification Methodologies for Enabling Extreme-Scale Science." Out of approximately 100 submissions, 6 were funded with 4 going to DOE National Laboratories and 2 to university-based consortia.

Professor Panos Kevrekidis was recently awarded the prestigious J. D. Crawford Prize from SIAM. See http://www.siam.org/prizes/sponsored/crawford.php for more details on the prize and the list of distinguished past recipients. As explained on this webpage, the J.D. Crawford Prize "is awarded to one individual for recent outstanding work on a topic in nonlinear science, as evidenced by a publication in English in a peer-reviewed journal within the four calendar years preceding the SIAG/DS meeting at which the prize is awarded."

During much of the summer of 2013 Professor Rob Kusner was working in Europe. Between May 30 and June 16, he was a visitor at Cambridge University's Churchill College and a member of the Isaac Newton Institute program on the Mathematics of Liquid Crystals. On June 12 he lectured on "CMC Surfaces in Riemannian Fibrations" at the University of Leicester's Workshop on Advances in Surface Theory during his visit to England. During the week of June 17-22, he participated in the conference on Variational Problems and Geometric PDEs at the new mathematics institute in Granada, Spain. And during the following month, he was a visiting research professor at the Centre de Recerca Matematica in Bellaterra, Barcelona, Catalunya, where on July 3 he lectured on "Necksizes for Soap Bubbles and Yamabe Metrics" and on "Conjugate Surface Constructions in Homogeneous 3-Manifolds." Rob detoured back to the ICMAT in Madrid, Spain, where on July 9 he lectured on "Nondegeneracy of Minimal and CMC Surfaces." Rob then visited his colleague Franz Pedit and his former students Nick Schmitt and Dugan Hammock at the Universitat Tubingen in Germany, July 19-21. After this visit he hiked a few kilometers southwest to the Mathematisches Forschingsinstitut Oberwolfach to participate in the mini-workshop on The Willmore Functional and the Willmore Conjecture during the week of July 22-27; there he delivered the opening lecture of the workshop on "Scherk's Surface and the Large-Genus Limit of the Willmore Problem." From July 27 to August 7 Rob worked in Brandenstein, a village just outside Berlin, with his long-time CMC-surfaces collaborators Karsten Grosse-Brauckmann and John Sullivan. Finally Rob visited physics colleagues at Ecole Polytechnique Federal de Lausanne in Switzerland, where on August 9 he lectured on "Chirality Invariants for Curves."

On May 30, 2013 Professor John Staudenmayer made a presentation titled "Advancing Objective Assessment of Physical Activity and Sedentary Behavior" at an invited symposium at the American College of Sports Medicine in Indianapolis, IN. In June 2013 John was invited to be a standing member of the NIH Kidney, Nutrition, Obesity, and Diabetes grant review study section.

During June and July 2013 Professor HongKun Zhang gave the following invited talks:

(1) A talk titled "Optimal Bound for Decay of Correlation for Nonuniformly Hyperbolic Systems" at the workshop Aspects Discrets des Systemes Dynamiques, held June 19-21 in Porquerolles, France.

(2) A talk titled "Diffusive Billiards" at the Conference on Random Dynamical Systems, held July 15-18 at the S-S Chern Institute in China.

(3) On July 13 a talk at the Workshop on Dynamical Systems at Beijing University in China.

### June 2013

During May 2013 Professor Tom Braden attended the Southeastern Lie Theory Workshop on Noncommutative Algebraic Geometry and Representation Theory. Harvard postdoc Carl Mautner and I gave expository lectures titled "Working with Parity Sheaves."

Professor Emeritus Aroldo Kaplan has been made a member of the National Academy of Sciences of Argentina. On June 7, 2013 he gave his inaugural talk titled "The Seven Mathematical Problems of the Millennium." The announcement can be viewed at http://www.anc-argentina.org.ar/web/actividades/actividad645. Professor Kaplan received his Ph.D. in 1971 from Washington University in St. Louis, and he joined our department in 1974 after three years as a Ritt Assistant Professor at Columbia University. He remained at UMass Amherst until his retirement in 2002. Since then he has been a researcher at CONICET, the National Scientific and Technical Research Council of Argentina, and at the University of Cordoba. Professor Kaplan is being recognized for his fundamental contributions to algebraic and differential geometry; in particular, his work on the Hodge theory of algebraic varieties with Eduardo Cattani at UMass Amherst, Pierre Deligne at the Institute for Advanced Study, and Wilfried Schmid at Harvard University.

Professor Panos Kevrekidis had a very busy spring semester. He was invited as one of the principal visitors at the University of Minnesota's Institute for Mathematics and its Applications (IMA) for their program on Infinite Dimensional and Stochastic Dynamical Systems and their Applications. During the semester, Panos visited and delivered invited talks at the following venues:

1) Department of Mathematics at Imperial College in London in February

2) Princeton University's Program in Applied and Computational Mathematics Colloquium in February

3) Jack Hale 1st Memorial Conference at Georgia Tech University in Atlanta in March

4) IMACS Nonlinear Waves Meeting in Athens, Georgia in March

5) Dynamical Systems Seminar at IMA in April

6) Department of Mathematics at University of Illinois at Urbana-Champaign in April, where he visited Zoi Rapti and Nikos Tzirakis, UMass alumni and current faculty members there

7) SIAM Dynamical Systems Conference in Snowbird, Utah in May

At Snowbird, Panos was also awarded the SIAM Activity Group in Dynamical Systems J.D. Crawford Prize. According to its principal guideline, the prize "is awarded to one individual for recent outstanding work on a topic in nonlinear science, as evidenced by a publication in English in a peer-reviewed journal within the four calendar years preceding the SIAG/DS meeting at which the prize is awarded."

Between April 27 and May 6, 2013 Professor Rob Kusner visited the Mathematisches Forschungsinstitut Oberwolfach in Germany to participate in both the Progress in Surface Theory and the Geometric Knots workshops there. Since May 29, 2013, he has been visiting the Isaac Newton Institute for Mathematical Sciences in England and collaborating with colleagues at the University of Cambridge.

Professor Franz Pedit was an organizer of the workshop Progress in Surface Theory, which took place at the Mathematisches Forschungsinstitut Oberwolfach in Germany during the period April 28 - May 4, 2013.

During the period May 7 - August 6, 2013 Professor Hongkun Zhang received a three-month researcher position in France that is supported by CNRS. She is conducting her research at the Centre de Physique Theorique in Luminy. On May 21 she gave an invited talk titled "Diffusive Billiards" at the Ernest Seminar (Team Dynamics, Arithmetic, Combinatorics) of the IML at Luminy. On May 30 she gave an invited talk with the same title at the International Conference Beyond Uniform Hyperbolicity held in Bedlewo, Poland during the period May 26 - June 26. On June 5 she gave an invited talk titled "Optimal Bound for Decay Rates of Correlations for Nonuniformly Hyperbolic Maps" at the conference on Limit Theorems for Dynamical Systems held in Lausanne, Switzerland during the period June 2-8.

On April 29, 2013 the annual Statistics Seminar took place at which M.S. students in statistics in the Department presented their M.S. projects. On May 6 the annual Applied Math Seminar took place at which MS students in applied math presented their MS projects. The Department had its annual reception for graduating seniors on May 11.