Los Alamos National Laboratory

The mission of the Los Alamos Center for Nonlinear Studies (CNLS) is fourfold:

• to identify and study fundamental nonlinear phenomena and promote their use in applied research,
• to stimulate interdisciplinary research and information exchanges inside and outside the laboratory,
• to provide a focal point for collaboration with academic and other scientific centers of excellence, and
• to disseminate recent developments and introduce young researchers to the subject.

The Center operates by overseeing postdoctoral, student and visitor programs, organizing conferences and workshops, and acting as a focal point for laboratory research staff. The roots of nonlinear science are in dynamical systems theory (stability and bifurcation theory, chaos, solitons) and statistical mechanics (fractals, scaling). Nonlinear science has more recently been identified with the study of complex and stochastic phenomena in multiscale, nonequilibrium and many-body systems, exemplified by the developing theories of pattern formations in many macroscopic physical, chemical and biological systems. Increasingly, research directions at CNLS are motivated by investigations of structures, both self-assembled and manufactured, at the meso-, micro-, and molecular scales. The overarching challenge in these studies is to identify key paradigms of self-organized structure formation and function in far-from-equilibrium many-body systems.

The current CNLS research efforts are organized annually into collaborative research projects which are divided into two broad "thrust" areas. Currently these are:

Thrust: Structure and Dynamics of Self-Assembling Systems Thrust: Modeling Nonlinear Systems

Projects: Landscapes and Dynamics in Proteins, Multiscale Phenomena in Materials, Self-Organization and Pattern Formation Projects: Applications of Nonlinear and Stochastic Dynamics, Discrete Simulation of Nonlinear Systems, Probabilistic and Combinatorial Analysis of Biological Systems

Projects in the first thrust area are focused on spontaneously generated and/or synthetic structures in natural systems, while those in the second thrust area are oriented toward developing the methods and techniques for modeling, analyzing, and simulating complex nonlinear systems.

Complex systems have recently become an area of great interest in physics, although much of the work has been theoretical with relatively little contact with experiment. The program in "Landscapes and Reactions in Proteins" proposes to focus the theoretical work on proteins: these biomolecules are clearly complex and highly nonlinear. Specifically, the goal is to exploit the concepts of energy landscapes and reactions (models, simulations and theories) in applications to experiments. Two types of reactions, bond formation and conformational motions, are under investigation, as are the effect of protein structure and external factors (Kramers' equation). Part of the emphasis is to outline the main unsolved problems, the crucial experimental features, and the strengths and weaknesses of the theoretical and computational approaches.