Handling editor:	Hinke Osinga
Photographs:	Bernd Krauskopf

Written by:

Björn Sandstede (University of Surrey, UK) and Rachel Kuske (University of British Columbia, Canada).

The Snowbird 2005 conference, held from 22-26 May 2005 in (you guessed it) Snowbird/Utah, was the eighth of a series of meetings organized by the SIAM Activity Group on Dynamical Systems. The biannual Snowbird conference is arguably one of the broadest and most important meetings for mathematicians, engineers and scientists interested in nonlinear dynamics and its interdisciplinary applications. In numbers: Snowbird 2005 drew 640 participants coming from 28 countries. About 594 of the attendees came from academia, 27 from Government, 15 from industry and 4 indicated none of these categories. The program consisted of 10 plenary presentations, 108 mini-symposia comprising 544 speakers, 55 contributed sessions with 152 talks, and a poster session with 46 posters. Fifteen mini-symposia involved organizers from industry, non-profit organizations, and various US and non-US government agencies or laboratories.

		The plenary talks represented a broad cross-section of recent mathematical results in dynamical systems theory, as well as engineering and scientific applications of nonlinear dynamics: Topics covered in dynamical systems areas ranged from theoretical results in ergodic theory, Hamiltonian maps and dispersive PDEs to new phenomena in pattern-forming systems. Other talks addressed interdisciplinary projects in turbulence, molecular dynamics and robotic locomotion, and real-life problems applications to electric power blackouts and call-center management. The ten speakers and their topics were:
Steve Smale delivers the Jürgen Moser Lecture.

• Rafael de la Llave, University of Texas, Austin
  Invariant Manifolds: Theorems, Algorithms and Conjectures
• Ian Dobson, University of Wisconsin, Madison
  Cascading Failureand Complex Dynamics in Large Blackouts
• Charles Doering, University of Michigan
  Turbulent Transport, Dissipation and Drag
• William A. Massey, Princeton University
  A Dynamical Systems Analysis for Stochastic Models of Call Centers
• Yasumasa Nishiura, Hokkaido University, Japan
  Dynamics of Particle Patterns in Dissipative Systems
• Andy Ruina, Cornell University
  The Existence and Stability of Limit Cycles as a Means to Understanding Animal- and Designing Robotic Locomotion
• Christof Schütte, Free University of Berlin, Germany
  Metastability in Complex Systems
• Gigliola Staffilani, Massachusetts Institute of Technology
  Recent Results on Local and Global Well-Posedness for some Dispersive Equations
• Shankar Venkataramani, University of Arizona
  Non-convex Variational Problems: Multiple-scale Behaviors in Equilibrium
• Amie Wilkinson, Northwestern University
  Stable Ergodicity: A Little Hyperbolicity is Often Enough

For some of the plenary speakers this was the first Snowbird conference that they had attended. This fact, together with their confirmation of enjoying DS05, is further evidence of the increasing breadth that the conference represents.

		The diversity of the broad research interests of the Snowbird community were very visible in the topics represented in the mini-symposia and contributed sessions. The overwhelming part of mini-symposium and contributed talks focused on how dynamical systems can be used in interdisciplinary research and how, conversely, applications generate new mathematical ideas and techniques. Overall, we felt that there was a good balance between sessions in more `traditional' application areas such as fluid dynamics and nonlinear optics, and newer emerging topics such as the equation-free coarse-grained simulation of multiscale problems and topological methods to classify patterns in Rayleigh-Bénard
Björn Sandstede at the Snowbird meeting.				Rachel Kuske at the Snowbird meeting.

convection and other systems. Theoretical core areas were represented with topics ranging from normal forms, Lyapunov exponents, nontwist Hamiltonian systems to hyperbolic dynamics. The contributed sessions were of very high quality and very well attended. Among the specific applications in industrial mathematics were the control and design of satellites, modeling issues in the biotech industry, and the dynamics of structures ranging from microwave devices to ships. Mathematical biology was again strongly represented with many sessions on neuroscience, synchrony, cardiac arrhythmias, angiogenesis, infectious decease spreading, swarming and slime molds, to name but a few. This year the number of mini-symposia covering stochastic processes saw a sharp increase, with applications in oceanography, biology, networks, and even one session discussing probabilistic models in sports.

One popular option for the mini-symposium format continues to be the opportunity for two-part mini-symposium sessions. This year there were 19 such double-headers, allowing an increased focus on a range of topics in industrial, computational, theoretical, and applied areas. Even more multi-part sessions were proposed, but due to space and time constraints some of these were combined into a single session (see the end of this article). Several sessions included a new option available this year: closing a longer mini-symposium session with a panel discussion on the session topic, with the speakers as the panel.

John Guckenheimer hands Dwight Barkley the JD Crawford Prize.

At a ceremony on the first evening of the conference, the SIAM Activity Group awarded the Jürgen Moser Lecture Prize and the JD Crawford Prize. The 2005 Jürgen Moser Lecture Prize was awarded to Stephen Smale (Toyota Technological Institute at Chicago) who spoke about Dynamics and Learning. The recipient of the 2005 JD Crawford Prize is Dwight Barkley (University of Warwick).

		The evening poster session, with dessert and coffee, has continued to be a very well attended, successful event. Jim Yorke, together with Robert Ghrist, Mark Levi, Paul Milewski, Wim van Saarloos and William Troy, who served as judges, awarded four "Red Sock Awards" for the most outstanding posters. The recipients of a (new) pair of red socks and a cash prize of $100 each were Margaret Beck (Boston University) Maria Leite (University of Houston) Maria Carmen Romano and Marco Thiel (University of Potsdam) Yulia Timofeeva (Heriot-Watt University)
Jim Yorke with one of the Red Sock Awards.

Jim York with the winners of the poster session, from left to right: Margaret Beck, Maria Leite, Marco Thiel, Maria Carmen Romano, and Yulia Timofeeva.

This year, DSWeb ran for the first time a graduate student competition for tutorials on dynamical systems; see also the featured Tutorials article. Evelyn Sander, the Section-Chief-Editor of DSWeb Tutorials, announced the winners of this contest:

Sam Reid (University of Colorado at Boulder) David M. Winterbottom (University of Nottingham) Shawn C. Shadden (California Institute of Technology) Brian Bockelman (University of Nebraska at Lincoln) was runner-up, and Sebastian M. Marotta (Boston University) and Gouhei Tanaka (University of Tokyo) received honorable mentions.
		Winners of the DSWeb Tutorials competition.

So far for the good news. The flipside of the success of the Snowbird meetings is their continued growth, seemingly without bounds: We received 128 mini-symposium submissions for Snowbird 2005, an increase by roughly 15% from the numbers for 2003, with space and time allotted in the program for only 110. This increase occurred despite announcing, and enforcing, for the first time a limit of two mini-symposium talks per speaker. Thus, we had, again for the first time, to reduce the number of sessions for reasons of space rather than quality or appropriateness of the proposed topic. This year we were able to minimize the number of rejections by combining some sessions and replacing some mini-symposia proposed as two shorter sessions with one longer session.

Various suggestions were made during the SIAG business meeting to address this issue. One possibility is to enforce an existing SIAM rule that limits speakers to one mini-symposium talk (not counting speakers who filled in for colleagues who cancelled their talks, there were 50 speakers with two mini-symposium talks). Another possibility is to allow potential mini-symposium organizers to post title and abstract of their proposed session on a central website, thus making it possible to coordinate and combine sessions with overlapping topics before submitting speaker names to SIAM.

We would like to thank SIAM's conference staff who organized and managed all logistical aspects of this meeting in an extremely efficient and professional fashion. We are also grateful to the other members of the Organizing Committee, namely Nick Ercolani, Robert Ghrist, John Guckenheimer, Mark Levi, and Emily Stone, for their tremendous help and support in putting this meeting together.

In the hope of seeing many of you at Snowbird 2007,

Rachel Kuske and Björn Sandstede
Co-Chairs, DS05.