Research Interests
My main research interests lie in mathematical logic. Currently, I am focussing on automata and automatic structures. Automata theory has been used to study groups (e.g. Thurston's work on the word problem), has applications in model checking and verification questions (e.g. in databases), and has been used in solving engineering problems such as (near) optimal control of hybrid systems and alternate algorithms for linear programming.
Questions about automatic structures may be grouped into two themes: developing structural characterisations and studying the algorithmic consequences of such characterisations. I have worked in both of these areas, including proving both positive and negative results about the existence of such characterizations. I am interested in answering these guiding questions in the context of less understood classes of structures (e.g. Thurston automatic groups, sequences from symbolic dynamics and combinatorics).
Another line of work seeks to answer "effective algebra" questions in the context of automatic structures. Much work has been done in understanding how the standard results of model theory change when restricted to the framework of computable or polynomial-time objects. Answering analogous questions about automatic structures both gives a better sense of the descriptive power of automata and of the relations between these different models of computation. For example, preliminary work has shown that, like polynomial-time structures (and unlike computable structures), automatic structures have a strong sensitivity to domain representation.