Hi all,
this week we will have two seminars:
- On Tuesday at 14:00 in HCI F2 Viktoria Kabel will talk about “Quantum Reference Frames & Subregions in Spacetime”
- On Friday at 14:00 in HIT J52 Jakob Miller will talk about “Improving the performance of two-source randomness extractors against quantum side-information”
see below for the abstracts.
Best,
Ladina
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Title:
Quantum Reference Frames & Subregions in Spacetime
Abstract:
In this talk, I will dive into the connection between quantum reference frames and the study of subregions in general relativity. The first part of the talk will motivate the concept of edge modes - additional degrees of freedom that arise at the boundary of subregions in gauge theory and gravity - and provide a gentle introduction to the mathematical tools used to study them. In the second part of the talk, these ideas will be applied to subregions in linearised general relativity. Here, edge modes arise naturally at the boundary of spacetime subregions and can be interpreted as reference frames for the diffeomorphism group. When quantising the theory, we must account for these degrees of freedom, which gives rise to quantum reference frames at the boundary of spacetime.
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Title:
Improving the performance of two-source randomness extractors against quantum side-information
Abstract:
In most (quantum) cryptographic protocols perfect randomness is an essential resource that is typically taken for granted, although the existence of real-world sources of perfect randomness is questionable. Fortunately, randomness extractors can bridge the gap between theory and implementation. Illustrated by the above application, in this talk we introduce two-source extractors against quantum/classical side-information. In particular, we discuss side-information in the product and Markov model. We derive a new XOR lemma that allows for significant improvements of the achievable output length of the extractors first introduced by Dodis et al. and that promises further improvements for a wide range of two-source extractors.