Parameterized Complexity in the Polynomial Hierarchy was co-recipient of
the E.W. Beth Dissertation Prize 2017 for outstanding dissertations in
the fields of logic, language, and information. This work extends the
theory of parameterized complexity to higher levels of the Polynomial
Hierarchy (PH). For problems at higher levels of the PH, a promising
solving approach is to develop fixed-parameter tractable reductions to
SAT, and to subsequently use a SAT solving algorithm to solve the
problem. In this dissertation, a theoretical toolbox is developed that
can be used to classify in which cases this is possible. The use of this
toolbox is illustrated by applying it to analyze a wide range of
problems from various areas of computer science and artificial
intelligence.