Anders Logg is a professor of computational mathematics at Chalmers University of Technology in Gothenburg, Sweden, and director of its Digital Twin Cities Centre, a Vinnova Competence Centre devoted to the study and development of the digital twin concept for city modelling and simulation. His research interests are adaptive finite element methods, high-level automating software systems for solution of PDE, domain-specific languages and compilers in scientific computing, augmented and virtual reality, and applications in biomedicine, general relativity, architecture and geoinformation – in particular the combination of modelling, simulation and visualization to create digital twins of physical systems.