14,222 research outputs found
Dynamics for holographic codes
We describe how to introduce dynamics for the holographic states and codes
introduced by Pastawski, Yoshida, Harlow and Preskill. This task requires the
definition of a continuous limit of the kinematical Hilbert space which we
argue may be achieved via the semicontinuous limit of Jones. Dynamics is then
introduced by building a unitary representation of a group known as Thompson's
group T, which is closely related to the conformal group in 1+1 dimensions. The
bulk Hilbert space is realised as a special subspace of the semicontinuous
limit Hilbert space spanned by a class of distinguished states which can be
assigned a discrete bulk geometry. The analogue of the group of large bulk
diffeomorphisms is given by a unitary representation of the Ptolemy group Pt,
on the bulk Hilbert space thus realising a toy model of the AdS/CFT
correspondence which we call the Pt/T correspondence.Comment: 40 pages (revised version submitted to journal). See video of related
talk: https://www.youtube.com/watch?v=xc2KIa2LDF
Limited phase deviation frequency multiplier phase modulator, appendix e final report
Limited phase deviation frequency multiplier phase modulator - application to radio frequency test console equipmen
Perspectives on subnational carbon and climate footprints: A case study of Southampton, UK
Sub-national governments are increasingly interested in local-level climate change management. Carbon- (CO2 and CH4) and climate-footprints—(Kyoto Basket GHGs) (effectively single impact category LCA metrics, for global warming potential) provide an opportunity to develop models to facilitate effective mitigation. Three approaches are available for the footprinting of sub-national communities. Territorial-based approaches, which focus on production emissions within the geo-political boundaries, are useful for highlighting local emission sources but do not reflect the transboundary nature of sub-national community infrastructures. Transboundary approaches, which extend territorial footprints through the inclusion of key cross boundary flows of materials and energy, are more representative of community structures and processes but there are concerns regarding comparability between studies. The third option, consumption-based, considers global GHG emissions that result from final consumption (households, governments, and investment). Using a case study of Southampton, UK, this chapter develops the data and methods required for a sub-national territorial, transboundary, and consumption-based carbon and climate footprints. The results and implication of each footprinting perspective are discussed in the context of emerging international standards. The study clearly shows that the carbon footprint (CO2 and CH4 only) offers a low-cost, low-data, universal metric of anthropogenic GHG emission and subsequent management
Locked oscillator phase modulator, appendix d final report
Design parameters for linear phase modulation of locked oscillato
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