Renormalization of multicritical scalar models in curved space

We consider the leading order perturbative renormalization of the multicritical $\phi^{2n}$ models and some generalizations in curved space. We pay particular attention to the nonminimal interaction with the scalar curvature $\frac{1}{2}\xi \phi^2 R$ and discuss the emergence of the conformal value of the coupling $\xi$ as the renormalization group fixed point of its beta function at and below the upper critical dimension as a function of $n$. We also examine our results in relation with Kawai and Ninomiya's formulation of two dimensional gravity.Comment: 13 pages, 3 figures; v3: matches the published versio

Functional Renormalisation Group analysis of a Tensorial Group Field Theory on R3\mathbb{R}^3

We study a model of Tensorial Group Field Theory (TGFT) on $\mathbb{R}^3$ from the point of view of the Functional Renormalisation Group. This is the first attempt to apply a renormalisation procedure to a TGFT model defined over a non-compact group manifold. IR divergences (with respect to the metric on $\mathbb{R}$) coming from the non-compactness of the group are regularised via compactification, and a thermodynamic limit is then taken. We identify then IR and UV fixed points of the RG flow and find strong hints of a phase transition of the TGFT system from a symmetric to a broken or condensate phase in the IR.Comment: 7 pages, 2 Figure

Non separable Werner states in spontaneous parametric down-conversion

The multiphoton states generated by high-gain spontaneous parametric down-conversion (SPDC) in presence of large losses are investigated theoretically and experimentally. The explicit form for the two-photon output state has been found to exhibit a Werner structure very resilient to losses for any value of the gain parameter, g. The theoretical results are found in agreement with the experimental data. The last ones are obtained by quantum tomography of the state generated by a high-gain SPDC.Comment: 16 pages, 6 figure

Bioethanol in biofuels checked by an amperometric organic phase enzyme electrode (OPEE) working in “substrate antagonism” format

The bioethanol content of two samples of biofuels was determined directly, after simple dilution in decane, by means of an amperometric catalase enzyme biosensor working in the organic phase, based on substrate antagonisms format. The results were good from the point of view of accuracy, and satisfactory for what concerns the recovery test by the standard addition method. Limit of detection (LOD) was on the order of 2.5 × 10−5 M. © 2016 by the authors; licensee MDPI, Basel, Switzerland

Covariant spin-parity decomposition of the Torsion and Path Integrals

We propose a functional measure over the torsion tensor. We discuss two completely equivalent choices for the Wheeler-DeWitt supermetric for this field, the first one being based on its algebraic decomposition, the other inspired by teleparallel theories of gravity. The measure is formally defined by requiring the normalization of the Gaussian integral. To achieve such a result we split the torsion tensor into its spin-parity eigenstates by constructing a new, York-like, decomposition. Of course, such a decomposition has a wider range of applicability to any kind of tensor sharing the symmetries of the torsion. As a result of this procedure a functional Jacobian naturally arises, whose formal expression is given exactly in the phenomenologically interesting limit of maximally symmetric spaces. We also discuss the explicit computation of this Jacobian in the case of a $4$-dimensional sphere $S^4$ with particular emphasis on its logarithmic divergences.Comment: 20 pages, 1 tabl

Aspects of critical phenomena in curved space

In this thesis we study examples of critical behavior of quantum systems coupled to a background metric. The analysis is performed with the double purpose of extracting information about matter degrees of freedom and gravitational degrees of freedom. Different formulations of the renormalization group are reviewed and applied to extract the critical properties of the systems under examination. In particular we focus on two classes of systems. First we analyze the behavior of chiral fermionic matter on negatively curved space which typically exhibit an enhanced tendency towards chiral symmetry breaking due to the background curvature. In this thesis we argue that, due to the high energies involved near the Planck regime, this phenomenon could result in the generation of heavy fermionic particles; inconsistent with the current observations of particle physics. We perform a scale dependent analysis to identify a set of parameters which rules out such a scenario and can lead to a criterion to for the falsification of models of quantum gravity. We claim that any theory of quantum gravity that admits a formulation in terms of a local field theory of the metric should respect our constraint or provide an alternative mechanism to solve the problem. The second class of systems we study is a tower of infinite scalar models with multicritical properties. Here we analyze their renormalization ow at leading order employing a covariant version of the epsilon expansion in dimensional regularization. We then investigate their analytical extension below the upper critical dimension paying particular attention to the fixed point value of the non minimal coupling to the background, which turns out to be the conformal value. Thanks to an improved parametrization of the action we can test the validity of our analysis against known results in the context of two dimensional quantum gravity couple to a large number of scalar fields and of statistical field theory in curved space

Morphological characterization of Amiata donkey through Multivariate analyses

ABSTRACT The objective of this study was to evaluate the morphology and biometrics of female Amiata donkeys reared in four different areas of southern Tuscany, Italy, to determine the differentiation degree of animals. Four southern Tuscan areas were investigated: two mountainous zones (East and West Amiata) and two flatter areas (Coastal area and Siena surrounding). Morphology and biometrics of adult female Amiata donkeys were collected to determine the homogeneity of the population. Primitive coat markings typical of the breed (shoulder and leg stripes) were found in Amiata donkey. Jennets from Siena surrounding were more dolichomorphic, while West Amiata individuals were smaller. The Principal Component Analysis and the Discriminant Analysis separated the Siena surrounding jennets from the other populations. This result was confirmed through the heatmap representation. The biometrics found in this research confirm that Amiata donkey is a small-medium sized breed suitable for different purposes

Entanglement, EPR correlations and mesoscopic quantum superposition by the high-gain quantum injected parametric amplification

We investigate the multiparticle quantum superposition and the persistence of multipartite entanglement of the quantum superposition generated by the quantum injected high-gain optical parametric amplification of a single photon. The physical configuration based on the optimal universal quantum cloning has been adopted to investigate how the entanglement and the quantum coherence of the system persists for large values of the nonlinear parametric gain g.Comment: 9 pages, 5 figure

Gravity in d=2+ϵd=2+\epsilon dimensions and realizations of the diffeomorphisms group

We discuss two distinct realizations of the diffeomorphism group for metric gravity, which give rise to theories that are classically equivalent, but quantum mechanically distinct. We renormalize them in $d=2+\epsilon$ dimensions, developing a new procedure for dimensional continuation of metric theories and highlighting connections with the constructions that previously appeared in the literature. Our hope is to frame candidates ultraviolet completions of quantum gravity in $d>2$ and give some perturbative mean to assess its existence in $d=4$, but also to speculate on some potential obstructions in the continuation of such candidates to finite values of $\epsilon$. Our results suggest the presence of a conformal window in $d$ which seems to extend to values higher than four.Comment: 17 pages, 1 figure; v2: improved draft in response to feedbac

How to Measure the ET-ET Construct for Ambidexterity Comparative Analysis of Measures and New Measurement Proposal

Although there is broad agreement that ambidexterity somehow relates to the simultaneous pursuit of exploratory and exploitative activities, a lack of conceptual clarity exists regarding the extent to which ambidexterity concerns matching the magnitude (BD) of exploration and exploitation on a relative basis, or concerns the combined magnitude (CD) of both activities. This fragmentation has inspired different operationalization of the construct and limited its usefulness, both for scholars and practitioners, since interpretations, comparisons and analysis between cross studies or research have become more difficult. This article proposes and tests an alternative measure of ambidexterity, which attempts to simultaneously and explicitly include in an overall index both the combined (CD) and the balanced dimension (BD)