Hi all,

next week there are two talks scheduled:

1. On Monday Finn Holler will tell us about “Quantum key distribution with less randomness”. The talk will take place at 16:00 in HIT E41.1

2. On Wednesday Renata Ferrero will tell us about “Observables and observers in quantum spacetime: a field theory perspective”. The talk will take place at 11:00 in HIT K51.

See below for the abstracts.

Best, Ladina

********** Title: Quantum key distribution with less randomness

Abstract: Perfect randomness is a key resource in cryptographic protocols, including quantum key distribution (QKD). Security proofs often rely on the availability of uniform and independent random bits, which are hard to obtain in practice. For instance, in QKD, the two honest parties Alice and Bob, typically use a uniformly random subset of rounds for statistical analysis during parameter estimation. By a random sampling argument, these observations are then used to make inferences about the remaining rounds. We investigate the use of samplers in parameter estimation, in order to reduced the randomness consumption of the protocol. Secondly, we investigated how a security proof would need to be adapted when a truly random source is replaced by a semi-random one, described by the Santha-Vazirani model.

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Title: Observables and observers in quantum spacetime: a field theory perspective

Abstract: Geometrical information of the quantum spacetime which we try to observe is carried by physical fields. Hence, observables cannot be properties of the “quantum spacetime” alone, but must also depend on the experimental setup that is used in order to probe them. I will give an overview about how to construct relational observables in both the canonical and the covariant (field theory) formalism and discuss their differences. I will then focus on the inclusion of quantum reference frames within the renormalization group program in quantum field theory.