Ring polymers are one of the last big mysteries in polymer physics, and this thesis tackles the problem of describing their behaviour when interacting in dense solutions and with complex environments and reports key findings that help shed light on these complex issues. The systems investigated are not restricted to artificial polymer systems, but also cover biologically inspired ensembles, contributing to the broad applicability and interest of the conclusions reached. One of the most remarkable findings is the unambiguous evidence that rings inter-penetrate when in dense solutions; here this behaviour is shown to lead to the emergence of a glassy state solely driven by the topology of the constituents. This novel glassy state is unconventional in its nature and, thanks to its universal properties inherited from polymer physics, will attract the attention of a wide range of physicists in the years to come.

Auteur
After his undergraduate studies in Padova (Italy) Davide Michieletto moved to the UK in 2011 where he attended the Doctoral Training Centre in Complexity Science at the University of Warwick until 2015. During this time he worked on a number of projects, the main one with Prof. Matthew Turner leading to his PhD in Physics and Complexity Science for a study of Topological Interactions in Ring Polymers. In September 2015 he became a Post-Doctoral Research Associate at the University of Edinburgh, working with Prof. Davide Marenduzzo on biophysical models for DNA and chromatin organisation in the cell nucleus.

Contenu
Introduction.- Predicting the Behaviour of Rings in Solution.- Molecular Dynamics Models.- Threading Rings.- A Biophysical Model for the Kinetoplast DNA.- The Role of Topology in DNA Gel Electrophoresis.- Conclusions.