Cadair - Aberystwyth University Open Access Repository
http://cadair.aber.ac.uk:80/dspace
The Cadair digital repository system captures, stores, indexes, preserves, and distributes digital research material.2017-05-23T02:20:31ZInformation geometry and local asymptotic normality for multi-parameter estimation of quantum Markov dynamics
http://hdl.handle.net/2160/45183
Information geometry and local asymptotic normality for multi-parameter estimation of quantum Markov dynamics
Guta, Madalin; Kiukas, Jukka
This paper deals with the problem of identifying and estimating dynamical parameters of continuous-time Markovian quantum open systems, in the input-output formalism. First, we characterise the space of identifiable parameters for ergodic dynamics, assuming full access to the output state for arbitrarily long times, and show that the equivalence classes of undistinguishable parameters are orbits of a Lie group acting on the space of dynamical parameters. Second, we define an information geometric structure on this space, including a principal bundle given by the action of the group, as well as a compatible connection, and a Riemannian metric based on the quantum Fisher information of the output. We compute the metric explicitly in terms of the Markov covariance of certain “fluctuation operators” and relate it to the horizontal bundle of the connection. Third, we show that the system-output and reduced output state satisfy local asymptotic normality, i.e., they can be approximated by a Gaussian model consisting of coherent states of a multimode continuous variables system constructed from the Markov covariance “data.” We illustrate the result by working out the details of the information geometry of a physically relevant two-level system
2017-05-11T00:00:00ZThe Dirichlet problem in a planar domain with two moderately close holes
http://hdl.handle.net/2160/45182
The Dirichlet problem in a planar domain with two moderately close holes
Dalla Riva, Matteo; Musolino, Paolo
We investigate a Dirichlet problem for the Laplace equation in a domain of R2 with two small close holes. The domain is obtained by making in a bounded open set two perforations at distance |ϵ1| one from the other and each one of size |ϵ1ϵ2|. In such a domain, we introduce a Dirichlet problem and we denote by uϵ1,ϵ2 its solution. We show that the dependence of uϵ1,ϵ2 upon (ϵ1,ϵ2) can be described in terms of real analytic maps of the pair (ϵ1,ϵ2) defined in an open neighbourhood of (0,0) and of logarithmic functions of ϵ1 and ϵ2. Then we study the asymptotic behaviour of uϵ1,ϵ2 as ϵ1 and ϵ2 tend to zero. We show that the first two terms of an asymptotic approximation can be computed only if we introduce a suitable relation between ϵ1 and ϵ2.
2017-04-12T00:00:00Z'Bottlenose' and 'The Greenhouse Effect'
http://hdl.handle.net/2160/45181
'Bottlenose' and 'The Greenhouse Effect'
Goodwin, Gavin
Two poems.
2017-01-01T00:00:00ZThe European Legal Regime on Trafficking in Human Beings
http://hdl.handle.net/2160/45180
The European Legal Regime on Trafficking in Human Beings
Piotrowicz, Ryszard
This chapter sets out the complex regime of EU law, Council of Europe law, and soft law, on trafficking of human beings. It demin startes how the various regimes are connected to each other and how they cannot be understood in isolation. It demonstartes the relevant of humanr gihts law to trafficking, espceially the case law of the European Court of Human Rights, and points out weaknesses in the European system.
2017-09-01T00:00:00Z