Discrete-Time Controllability for Feedback Quantum Dynamics

Controllability properties for discrete-time, Markovian quantum dynamics are investigated. We find that, while in general the controlled system is not finite-time controllable, feedback control allows for arbitrary asymptotic state-to-state transitions. Under further assumption on the form of the measurement, we show that finite-time controllability can be achieved in a time that scales linearly with the dimension of the system, and we provide an iterative procedure to design the unitary control actions

Remarks on Neumann boundary problems involving Jacobians

In this short note we explore the validity of Wente-type estimates for Neumann boundary problems involving Jacobians. We show in particular that such estimates do not in general hold under the same hypotheses on the data for Dirichlet boundary problems

Rural landscape valuation in a cross-border region

The rural landscape is one of the most valuable agricultural externalities and it is often affected by modifications in the agricultural production process. Moreover, some rural areas are deteriorating due to the depopulation process while others are being transformed owing to socio-economic pressures. However, should agricultural policies concerning landscape preservation only be considered as cost items or should they be seen as sources of social benefits able to justify economic support? On this basis two surveys were carried out in order to study the economic value of the rural landscape, focusing in particular on viticulture. Both studies covered quality wine-producing areas on the Italian/Slovenian border: The Controlled Denomination of Origin zones of ‘Collio’ and ‘Colli Orientali del Friuli’ in Italy, and the municipality of Brda in Slovenia. Both surveys assessed the economic value of the rural landscape in order to estimate the social benefit that populations attach to landscape preservation measures. Despite the fact that similar methods were applied, results differed. The peculiar backgrounds affected our results in two ways. Firstly we found that there was a considerable difference in the way Italians and Slovenes valued the rural landscape. While Italians considered the development and extension of vineyards to be very important in counteracting the abandonment of rural areas, Slovenes preferred “traditional” landscapes (orchards, grasslands and vineyards). Secondly, in Slovenia it was difficult to apply the contingent valuation method, which is based on a hypothetical market scenario. More research should be carried out in order to study the methods that best fitthe preferences for rural landscape.rural landscape, contingent valuation method, Collio (Italy), Colli orientali del Friuli (Italy), Brda

Pimsner algebras and circle bundles

We report on the connections between noncommutative principal circle bundles, Pimsner algebras and strongly graded algebras. We illustrate several results with the examples of quantum weighted projective and lens spaces and theta-deformations.Comment: 24 pages. v3: Updated title. No changes in the scientific content and result

Accurate phase diagram of tetravalent DNA nanostars

We evaluate, by means of molecular dynamics simulations employing a realistic DNA coarse-grained model, the phase behaviour and the structural and dynamic properties of tetravalent DNA nanostars, i.e. nanoconstructs completely made of DNA. We find that, as the system is cooled down, tetramers undergo a gas--liquid phase separation in a region of concentrations which, if the difference in salt concentration is taken into account, is comparable with the recently measured experimental phase diagram [S. Biffi \textit{et al}, Proc. Natl. Acad. Sci, \textbf{110}, 15633 (2013)]. We also present a mean-field free energy for modelling the phase diagram based on the bonding contribution, derived by Wertheim in its studies of associating liquids, combined with mass action law expressions appropriate for DNA binding and a numerically evaluated reference free energy. The resulting free energy qualitatively reproduces the numerical data. Finally, we report information on the nanostar structure, e.g. geometry and flexibility of the single tetramer and of the collective behaviour, providing a useful reference for future small angle scattering experiments, for all investigated temperatures and concentrations.Comment: 10 pages, 11 figure