Generalized Crossover in multiparameter Hamiltonians

Many systems near criticality can be described by Hamiltonians involving several relevant couplings and possessing many nontrivial fixed points. A simple and physically appealing characterization of the crossover lines and surfaces connecting different nontrivial fixed points is presented. Generalized crossover is related to the vanishing of the RG function $Z_t^{-1}$. An explicit example is discussed in detail based on the tetragonal GLW Hamiltonian.Comment: 4 pages, 1figur

On the evaluation of the improvement parameter in the lattice Hamiltonian approach to critical phenomena

In lattice Hamiltonian systems with a quartic coupling $\gamma$, a critical value $\gamma^*$ may exist such that, when $\gamma=\gamma^*$, the leading irrelevant operator decouples from the Hamiltonian and the leading nonscaling contribution to renormalization-group invariant physical quantities (evaluated in the critical region) vanishes. The 1/N expansion technique is applied to the evaluation of $\gamma^*$ for the lattice Hamiltonian of vector spin models with O(N) symmetry. As a byproduct, systematic asymptotic expansions for the relevant lattice massive one-loop integrals are obtained.Comment: Conclusions clarified; 26 pages, 6 figures, RevTeX

Deciding the Satisfiability of MITL Specifications

In this paper we present a satisfiability-preserving reduction from MITL interpreted over finitely-variable continuous behaviors to Constraint LTL over clocks, a variant of CLTL that is decidable, and for which an SMT-based bounded satisfiability checker is available. The result is a new complete and effective decision procedure for MITL. Although decision procedures for MITL already exist, the automata-based techniques they employ appear to be very difficult to realize in practice, and, to the best of our knowledge, no implementation currently exists for them. A prototype tool for MITL based on the encoding presented here has, instead, been implemented and is publicly available.Comment: In Proceedings GandALF 2013, arXiv:1307.416

Carla Casagrande, Gianfranco Fioravanti (eds.), La filosofia in Italia al tempo di Dante, Casa editrice Il Mulino, Bologna 2016, (Le vie della civiltà), XXI + 291 PP. ISBN 97888256166

Review of: Carla Casagrande, Gianfranco Fioravanti (eds.), La filosofia in Italia al tempo di Dante, Casa editrice Il Mulino, Bologna 2016, (Le vie della civiltà), XXI + 291 PP. ISBN 978-88-25616-

Instructional planning and new technologies in teacher education: the initial phase of a research project

The purpose of this work is to present the initial phase of a research project focused on the integration of technologies in the education of kindergarten and primary school student teachers through instructional planning. Firstly, we illustrate a tool designed for planning integrated learning units and describe the training path in which it was used. Secondly, we report the results of a preliminary study conducted with 96 students attending a university course that investigates two personal traits considered as prerequisites for using the tool: perceived proficiency in technology use, and opinions on the importance of each constituent element of the tool. With regard to both traits, some statistically significant variations emerged. The results obtained are an encouragement to continue the research project to verify whether the tool could be suitable to help student teachers develop an integrated planning procedure

Gribov Copies in Lattice QCD

We have performed an exhaustive search for Gribov copies on the lattice and their possible dependence from finite temperature effects. We show that, for each value of lattice size, Gribov copies are dense in configuration space at low temperature but their density tend to lower when the temperature increases. We have investigated lattice sizes running from $16^3\times 8$ to $16^4$.Comment: 7 pages LaTex, UPRF February 93 preprint /321

Grating-Coupled Surface Plasmon Resonance (GC-SPR) Optimization for Phase-Interrogation Biosensing in a Microfluidic Chamber.

Surface Plasmon Resonance (SPR)-based sensors have the advantage of being label-free, enzyme-free and real-time. However, their spreading in multidisciplinary research is still mostly limited to prism-coupled devices. Plasmonic gratings, combined with a simple and cost-effective instrumentation, have been poorly developed compared to prism-coupled system mainly due to their lower sensitivity. Here we describe the optimization and signal enhancement of a sensing platform based on phase-interrogation method, which entails the exploitation of a nanostructured sensor. This technique is particularly suitable for integration of the plasmonic sensor in a lab-on-a-chip platform and can be used in a microfluidic chamber to ease the sensing procedures and limit the injected volume. The careful optimization of most suitable experimental parameters by numerical simulations leads to a 30–50% enhancement of SPR response, opening new possibilities for applications in the biomedical research field while maintaining the ease and versatility of the configuration