Observations over the past few decades have provided important evidence about the geometry of the large scale universe. During the early inflationary era, as well as the current vacuum dominated era, the evidence points to a universe described by an exponentially expanding de Sitter spacetime. From the perspective of theoretical physics, the last two decades have seen remarkable progress in our understanding of spacetime as an emergent, collective phenomenon stemming from a microscopic holographic system with a large number of `atomic' constituents. This has been achieved with great success for negatively curved anti-de Sitter spacetimes. We will explore holography for a de Sitter universe. Our discussion will be guided by the construction and consideration of concrete mathematical models, providing an exact realisation of the dS-CFT correspondence. We will also discuss similarities and distinctions between the cosmological horizon of a de Sitter universe and the horizon of an ordinary black hole from a modern, holographic perspective.
Dr. Dionysios Anninos graduated from Cornell University with a major in Physics, Mathematics and Economics in 2006. In 2011, he completed his doctoral work at Harvard University under the supervision of Andrew Strominger. He was a postdoctoral researcher at Stanford University from 2011-2014, a member of the Institute for Advanced Study from 2014-2017, and is currently a Fellow of the Delta Institute for Theoretical Physics. His work focuses on the interface between holography, cosmology and black hole physics.