Since 2002 Perimeter Institute has been recording seminars, conference talks, public outreach events such as talks from top scientists using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities.
Recordings of events in these areas are all available and On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
Accessibly by anyone with internet, Perimeter aims to share the power and wonder of science with this free library.
Quantum Electrodynamics
This year there appear several amazing experiments in the graphene moire superlattices. In this talk I will focus on the ABC trilayer graphene/h-BN system. Mott-like insulators at 1/4 and 1/2 of the valence band have already been reported by Feng Wang’s group at Berkeley. The sample is dual gated on top and bottom with voltage V_t and V_b. V_t+V_b controls the density of electrons. Interestingly we find that the displacement field D=V_t-V_b can control both the topology and the bandwidth of the valence band.
What does it mean for quantum state to be genuinely fully multipartite? Some would say, whenever the state cannot be decomposed as a mixture of states each of which has no entanglement across some partition. I'll argue that this partition-centric thinking is ill-suited for the task of assessing the connectivity of the network required to realize the state.
We consider implications of superrotations as an asymptotic symmetry of asymptotically flat spacetimes. Beginning with a review of the rich structure of interconnections between soft theorems, asymptotic symmetries, and memory effects, we describe the superrotation iteration. The subleading soft graviton theorem can be cast as a Ward identity for this asymptotic symmetry in 4D, and also as one for the stress tensor of a putative CFT2. We detail the change of scattering basis motivated by this asymptotic symmetry and discuss recent progress.
In July 2018 the Planck Collaboration released its final set of cosmology results. I will discuss some of the interesting new science that remains to be done with the CMB, including some not so often discussed topics such as the kinetic SZ effect and 21cm cross-correlations.
The Quantization of Electromagnetic Fields
A 3d N=4 gauge theory admits two topological twists, which we'll simply call A and B. The two twists are exchanged by 3d mirror symmetry. It is known that local operators in the A (resp. B) twist include the Coulomb-branch (resp. Higgs-branch) chiral rings. In this talk I will discuss the *line* operators preserved by the two twists, which in each case should have the structure of a braided tensor category.
Check back for details on the next lecture in Perimeter's Public Lectures Series