Parameter Space Compression Underlies Emergent Theories and Predictive Models
Abstract
The microscopically complicated real world exhibits behavior that often yields to simple yet quantitatively accurate descriptions. Predictions are possible despite large uncertainties in microscopic parameters, both in physics and in multiparameter models in other areas of science. We connect the two by analyzing parameter sensitivities in a prototypical continuum theory (diffusion) and at a selfsimilar critical point (the Ising model). We trace the emergence of an effective theory for longscale observables to a compression of the parameter space quantified by the eigenvalues of the Fisher Information Matrix. A similar compression appears ubiquitously in models taken from diverse areas of science, suggesting that the parameter space structure underlying effective continuum and universal theories in physics also permits predictive modeling more generally.
 Publication:

Science
 Pub Date:
 November 2013
 DOI:
 10.1126/science.1238723
 arXiv:
 arXiv:1303.6738
 Bibcode:
 2013Sci...342..604M
 Keywords:

 PHYSICS Physics, AppliedPhysics, Environment;
 Condensed Matter  Statistical Mechanics;
 Mathematical Physics;
 Physics  Data Analysis;
 Statistics and Probability;
 Quantitative Biology  Other Quantitative Biology
 EPrint:
 5 pages, 3 figures + 9 page Supplement, 1 additional figure