Latest evidence for a late time vacuum -- geodesic CDM interaction

We perform a reconstruction of the coupling function between vacuum energy and geodesic cold dark matter using the latest observational data. We bin the interaction in seventeen redshift bins but use a correlation prior to prevent rapid, unphysical oscillations in the coupling function. This prior also serves to eliminate any dependence of the reconstruction on the binning method. We use two different forms of the correlation prior, finding that both give similar results for the reconstruction of the dark matter -- dark energy interaction. Calculating the Bayes factor for each case, we find no meaningful evidence for deviation from the null interacting case, i.e. $\Lambda$CDM, in our reconstruction.Comment: 14 pages, 7 figures. Version 2 matches published version in Physics of the Dark Universe (Figure 2 updated to better show H0 and sigma 8 tensions, additional discussion of results added in section 4.1

Axion phenomenology and θ\theta-dependence from Nf=2+1N_f = 2+1 lattice QCD

We investigate the topological properties of $N_f = 2+1$ QCD with physical quark masses, both at zero and finite temperature. We adopt stout improved staggered fermions and explore a range of lattice spacings $a \sim 0.05 - 0.12$ fm. At zero temperature we estimate both finite size and finite cut-off effects, comparing our continuum extrapolated results for the topological susceptibility $\chi$ with predictions from chiral perturbation theory. At finite temperature, we explore a region going from $T_c$ up to around $4\, T_c$, where we provide continuum extrapolated results for the topological susceptibility and for the fourth moment of the topological charge distribution. While the latter converges to the dilute instanton gas prediction the former differs strongly both in the size and in the temperature dependence. This results in a shift of the axion dark matter window of almost one order of magnitude with respect to the instanton computation.Comment: 24 pages, 12 figures, 5 tables, final version published in JHE

Recent progress on QCD inputs for axion phenomenology

The properties of the QCD axion are strictly related to the dependence of strong interactions on the topological parameter theta. We present a determination of the topological properties of QCD for temperatures up to around 600 MeV, obtained by lattice QCD simulations with 2+1 flavors and physical quark masses. Numerical results for the topological susceptibility, when compared to instanton gas computations, differ both in size and in the temperature dependence. We discuss the implications of such findings for axion phenomenology, also in comparison to similar studies in the literature, and the prospects for future investigations.Comment: Invited talk at XII Quark Confinement, 29 August - 3 September, 2016, Thessaloniki, Greece, 9 pages, 6 figure

Hybrid Strategy to Achieve 3D Base Isolation of Structures

Some aspects, related to the 3D base isolation of structures to control the effects of both the horizontal and vertical components of ground motion, are presented in this paper. A massive structure (a Nuclear Power Plant building) equipped with a traditional horizontal base isolation system is numerically studied. The base isolation system uses rubber bearings (low and high damping) coupled with a tuned mass damper (TMD) in the vertical direction. Possible positive and negative aspects from the implementation of the proposed hybrid strategy are investigated. Numerical analyses show that the presence of the TMD mitigate the vertical effects of the three-dimensional ground motion coupled with the elastomeric bearings, reducing both the vertical and the horizontal absolute acceleration in the superstructure under certain conditions. Vertical acceleration in the superstructure appears related to the horizontal motion, due to the building’s centroid position that induces rocking

Robustness of RC girder bridges: The case of half-joint bridges

Considerable research efforts have been made on the progressive collapse resistance of buildings. This effort is much more limited in the case of bridges, where robustness criteria are just as, or even more important than in buildings. Existing studies dealing with the robustness of bridges, although appreciable, often are limited to qualitative considerations that can provide designers with valuable pointers when designing new bridges. It is equally important to assess not only the safety but also the robustness of existing bridges through reliable metrics that can be used in the prioritization of interventions by the managing authority. According to this aim, this paper applies a selected measure of robustness to a particular type of reinforced concrete (RC) girder bridge, namely half-joint bridges. The Annone viaduct, which collapsed in 2016 after the passage of a heavy truck, is used as a case study

Generation of different Bell states within the SPDC phase-matching bandwidth

We study the frequency-angular lineshape for a phase-matched nonlinear process producing entangled states and show that there is a continuous variety of maximally-entangled states generated for different mismatch values within the natural bandwidth. Detailed considerations are made for two specific methods of polarization entanglement preparation, based on type-II spontaneous parametric down-conversion (SPDC) and on SPDC in two subsequent type-I crystals producing orthogonally polarized photon pairs. It turns out that different Bell states are produced at the center of the SPDC line and on its slopes, corresponding to about half-maximum intensity level. These Bell states can be filtered out by either frequency selection or angular selection, or both. Our theoretical calculations are confirmed by a series of experiments, performed for the two above-mentioned schemes of producing polarization-entangled photon pairs and with two kinds of measurements: frequency-selective and angular-selective.Comment: submitted for publicatio

A Framework to Evaluate Information Quality in Public Administration Website

This paper presents a framework aimed at assessing the capacity of Public Administration bodies (PA) to offer a good quality of information and service on their web portals. Our framework is based on the extraction of “.it” domain names registered by Italian public institutions and the subsequent analysis of their relative websites. The analysis foresees an automatic gathering of the web pages of PA portals by means of web crawling and an assessment of the quality of their online information services. This assessment is carried out by verifying their compliance with current legislation on the basis of the criteria established in government guidelines[1]. This approach provides an ongoing monitoring process of the PA websites that can contribute to the improvement of their overall quality. Moreover, our approach can also hopefully be of benefit to local governments in other countries. Available at: https://aisel.aisnet.org/pajais/vol5/iss3/3