Hi,
Next week's seminar talk is by David Gross. It will take place on Tuesday, 30.11., 17:00, at CAB H 52 in Zentrum.
Best regards, Stefan
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Title:
In a discrete universe, no acceleration
Abstract:
I will present an analysis of the time evolutions that can be realized in one-dimensional quantum systems with discrete space and discrete time. We assume causality, in the sense that in any time step, information can propagate only a finite distance. In this setting, we find that there is a single, simple invariant - called the "index" for lack of a better name - which completely solves the following three problems:
1. Classify all time evolutions up to continuous deformations
2. Classify those dynamics which can be realized by sequential localized unitaries
3. Classify the pairs of time evolutions U_1, U_2 which can be "pieced together" in the sense that there exists a single large system U which behaves like U_1 in some parts an like U_2 in other parts.
I will also not fail to mention what my title has to do with any of that.
arxiv:0910.3675 (to appear in CMP).
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