Parameterized Complexity and Subexponential Time

Parameterized Complexity in its origins was considered by many researchers to be an exotic research eld, orthogonal to the standard way of classifying problems in complexity theory. In the last years however many surprising connections between Parameterized Complexity and classical areas in complexity theory have been established. Jörg Flum and Martin Grohe survey in this column some of these interesting connections including links to the areas of bounded nondeterminism, subexponential complexity or syntactic complexity classes.