My research focuses on modelling and analysing urban systems from the perspective of complexity sciences. My main branches of research are urban scaling laws, hierarchies in urban systems, defining city boundaries, and the analysis of urban processes using percolation theory and networks. 

I am particularly interested in understanding how urban attributes are characterised by the size of cities, and in identifying common patterns across different urban systems. This problem embraces a more fundamental one, which is the definition of a city. In this respect, we have created thousands of definitions by varying parameters concerned with the morphological and the functional aspects of cities. These serve as a laboratory to explore the sensitivity of models to city definitions, which are created from bottom-up. 

On the other hand, applying networks and percolation theory to the urban infrastructure, we have uncovered hierarchical structures that have historical and socio-economical roots, and these are of relevance to the current regional inter-connectivity and its economic development. Together with RAs and PhD students, we use these as a framework to develop performance indicators of cities, and measures of inequality applying multifractal methodologies. We complement this picture with economic data at the micro-level from the Business Structure Database, 1997-2016, and explore the spatial dynamical structure of firms in the UK. The research has been developed under an EPSRC grant on Digital Economies, and an ERC (European Research Council) funded project lead by Prof. Michael Batty entitled MECHANICITY: Morphology, Energy and Climate cHANge In the CITY. Aspects related to smart cities and policy have been investigated under a MacArthur funded research project.