Phase diagram of exciton topological phases: a,b, Diagrams for the upper and lower energy exciton Hamiltonians (v = L, U), respectively. Light and dark blue regions denote topologically non-trivial phases with Chern number equal to − 1 and 1, exhibiting edge states with anticlockwise and clockwise exciton currents, respectively. Switching the direction of the magnetic field to Bz
Aquatic swimming: a,The organisms considered in the article span eight orders of magnitude in Reynolds number and encompass larvae (from mayfly to zebrafish), fish (from goldfish, to stingrays and sharks), amphibians (tadpoles), reptiles (alligators), marine birds (penguins) and large mammals (from manatees and dolphins to belugas and blue whales). Blue fish sketch by Margherita Gazzola. b, Swimmer of length L is propelled forward with velocity U by pushing a bolus of water14, 20, 24 through body undulations characterized by tail beat amplitude A and frequency ω.
Known empirical scaling laws for gray-matter volume and thickness are mapped on a g2 vs. R/T diagram. Corresponding simulations for spherical brain configurations, with images shown at a few points, show that the surface remains smooth for the smallest brains, but becomes increasingly folded as the brain size increases. [From T. Tallinen, J.Y. Chung, J.S. Biggins, and L. Mahadevan, "Gyrification from constrained cortical expansion," PNAS 2014 | doi:10.1073/pnas.1406015111]
Professor Andrew Strominger is one of three scholars awarded the 2014 Dirac Medal by the Abdus Salam International Centre for Theoretical Physics for their "crucial contributions to the origin, development and further understanding of string theory".
Prof. Strominger "has been a major figure in uncovering geometric solutions of string theory and has made important contributions to the understanding of black holes in quantum gravity".
For more on the ICTP and the Dirac Medal, please see the Institute's website.