Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events 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 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.
Motivated by the consistency of black hole complementarity, Sekino and Susskind have conjectured that no physical system can "scramble" its internal degrees of freedom in time faster than (1/T) log S, where T is temperature and S the system's entropy. By considering a number of toy examples and general Lieb-Robinson-type causality bounds, I'll explore the range of validity of the conjecture. Some of these examples suggest that nonlocal Hamiltonians can delocalize information at rates exceeding the fast scrambling bound, but the physical relevance of these examples is unclear.
We investigate a simple FRW spacetime realized by a brane construction. This also comes from a Coleman-de Luccia decay from a metastable de Sitter. We motivate a dual description in terms of a low energy effective field theory (EFT) on FRW in one lower dimensions. This EFT is coupled to gravity with a time-dependent Planck mass that grows to infinity at late times. We investigate the entropy bound, correlation functions, and various particle/brane probes as first steps to understand the degrees of freedom building up the EFT. This is work in collaboration with B. Horn, S. Matsuura, E.
I will discuss recent work engineering "semi-holographic" constructions of de Sitter space in string theory, using elliptic fibrations and orientifolds to uplift known Freund-Rubin compactifications. The dual brane construction is compact and provides a microscopic realization of the dS/dS correspondence of Alishahiha et al., realizing de Sitter space in d dimensions as a warped compactification down to d-1 dimensional de Sitter space coupled to a pair of large N matter sectors. This provides a parametric microscopic accounting of the Gibbons-Hawking entropy.
Neutron star mergers represent one of the most promising sources of gravitational waves (GW), while that the presence of strong magnetic fields may offer the possibility of a characteristic electromagnetic signature allowing for concurrent detection. In this talk will be presented a new hybrid-passive approach to match the full GR-MHD evolutions of the binary neutron star mergers to the force-free equations in order to study numerically the dynamics and interaction of their magnetospheres.
Starting from AdS/CFT, one can introduce ingredients which produce cosmological solutions, including metastable de Sitter and its decay to FRW. In the de Sitter case, this produces a compact brane construction which mirrors the dS/dS correspondence realizing de Sitter as a pair of warped throats coupled to gravity. In the FRW case, I will present simple solutions sourced by magnetic flavor branes and explore their holographic description.
Gauge/gravity duality is our most complete construction of quantum gravity, but it gives in a simple way only the observations of an observer at the AdS boundary. I discuss various issues regarding the representation of the bulk physics.
Black hole-neutron star (BHNS) binary mergers areimportant gravitational wave sources and (possibly) gamma ray burst progenitors. Fully relativisticsimulations have only recently begun to try to capture neutron star physics beyond the polytrope approximation.
I'll discuss some recent insights regarding the complexity of simulating highly entangled quantum systems using classical and quantum computers, and what these advances might imply about the quantum state of the early universe.
Check back for details on the next lecture in Perimeter's Public Lectures Series