Robert Engle

New York University

Biggest contribution: Autoregressive conditional heteroskedasticity, or ARCH

Cocktail-party definition: A model for predicting risk in a financial portfolio.

Who's listening: Virtually every hedge fund, investment bank, and money manager on Wall Street uses Engle's model; it won him the Nobel Prize in 2003.

Janine Benyus

University of Montana

Biggest contribution: Biomimicry

Cocktail-party definition: Industrial applications based on designs in nature, like solar cells that can mimic the photosynthesis of plant leaves.

Who's listening: Boeing, General Electric, Herman Miller, and the North Face are clients of the Biomimicry Guild, which Benyus co-founded.

Tuomas Sandholm

Carnegie Mellon University

Biggest contribution: Combinatorial optimization

Cocktail-party definition: The algorithms behind enhanced business-to-business auction sites, which match buyers and sellers using more complex factors than just price (like shipping times, legal issues, and insurance limits).

Who's listening: Procter & Gamble, Siemens, the United States Postal Service, and Whirlpool have all bought goods and services through ­CombineNet, Sandholm's auction platform.