Description de l’épisode
Jean-François JoannyMatière molle et biophysiqueCollège de FranceAnnée 2024-2025Conférence - Mark Bowick - Nonabelian Topological DefectsMark BowickDeputy Director, Kavli Institute for Theoretical Physics, University of California Santa BarbaraMark Bowick est invité par l'assemblée du Collège de France sur proposition du professeur Jean-François Joanny, chaire Matière molle et biophysique.The line defects of three dimensional uniaxial nematics have a simple abelian algebra governing their interactions and so simply pass through one another. I will discuss, instead, biaxial nematics for which the fundamental group is non-abelian. As a result they exhibit topological entanglement/rigidity, trivalent junctions and associated networks, and stable bound states of pairs of disclinations. They can be experimentally realized in chiral nematics or in hybrid molecular-colloidal systems, realizing the notion of topological rigidity envisaged 50 years ago by Poenaru and Toulouse.Mark BowickMark Bowick was born in New Zealand, obtained his B.Sc.(Hons) from the University of Canterbury (New Zealand) and a Ph.D. in theoretical particle physics from Caltech in 1983. This was followed by a Research Associate position in the Particle Theory Group at Yale, winning the First prize award in the 1986 Gravity Research Foundation Essay Competition. This was followed by a postdoctoral position in the Center for Theoretical Physics at MIT. He joined the faculty of the Physics Department at Syracuse University in 1987, holding an Outstanding Junior Investigator award from the Department of Energy from 1987-1993 and becoming Full Professor of Physics in 1998. His research career has been split between theoretical high-energy physics and condensed matter (principally soft matter). He was elected a Fellow of the American Physical Society (Division of Condensed Matter Physics) in 200
