## SCL Online Seminar by Mihailo Čubrović

You are cordially invited to the SCL online seminar of the Center for the Study of Complex Systems, which will be held on Thursday, 24 December 2020 at 14:00 on Zoom. The talk entitled

will be given by Dr. Mihailo Čubrović (Scientific Computing Laboratory, Center for the Study of Complex Systems, Institute of Physics Belgrade). Abstract of the talk:

In this talk we will consider two distinct but somewhat analogous phenomena: traversable wormholes ("shortcuts" through spacetime) and quantum teleportation (instantaneous transfer of quantum information). Both are known to be possible under certain circumstances, mainly in idealized setups at zero density and temperature. We will consider the dynamics of finite density matter in the vicinity of a model traversable wormhole and show that the scattering is very strongly chaotic (exhibiting so-called Wada basins), which in turn introduces strong instabilities that generically destroy the wormhole. Similarly, quantum teleportation between two strongly coupled spin systems (generalized Sachdev-Ye-Kitaev models) introduces large and long-living perturbations (computed within the mean-field theory). We will find out that teleportation between large and strongly interacting systems is much more difficult. As a sanity check, we will repeat the wormhole calculation in anti-de Sitter (AdS) space where, through the AdS/CFT correspondence, it becomes exactly equivalent (rather than just analogous) to two entangled Sachdev-Ye-Kitaev systems, and again find that the wormhole/entanglement likely does not survive the transport/teleportation attempt. On a brighter side, these negative results soften the black hole information paradox in AdS space: since the teleportation (in this case between Alice outside the black hole and Bob inside it) is much slower and much more fragile than usually assumed, the no-cloning theorem can be satisfied and there is likely no unitarity violation.

**No free lunch: how strong correlations and chaotic wormholes kill teleportation**will be given by Dr. Mihailo Čubrović (Scientific Computing Laboratory, Center for the Study of Complex Systems, Institute of Physics Belgrade). Abstract of the talk:

In this talk we will consider two distinct but somewhat analogous phenomena: traversable wormholes ("shortcuts" through spacetime) and quantum teleportation (instantaneous transfer of quantum information). Both are known to be possible under certain circumstances, mainly in idealized setups at zero density and temperature. We will consider the dynamics of finite density matter in the vicinity of a model traversable wormhole and show that the scattering is very strongly chaotic (exhibiting so-called Wada basins), which in turn introduces strong instabilities that generically destroy the wormhole. Similarly, quantum teleportation between two strongly coupled spin systems (generalized Sachdev-Ye-Kitaev models) introduces large and long-living perturbations (computed within the mean-field theory). We will find out that teleportation between large and strongly interacting systems is much more difficult. As a sanity check, we will repeat the wormhole calculation in anti-de Sitter (AdS) space where, through the AdS/CFT correspondence, it becomes exactly equivalent (rather than just analogous) to two entangled Sachdev-Ye-Kitaev systems, and again find that the wormhole/entanglement likely does not survive the transport/teleportation attempt. On a brighter side, these negative results soften the black hole information paradox in AdS space: since the teleportation (in this case between Alice outside the black hole and Bob inside it) is much slower and much more fragile than usually assumed, the no-cloning theorem can be satisfied and there is likely no unitarity violation.