Calculi, Hodge operators and Laplacians on a quantum Hopf fibration

We describe Laplacian operators on the quantum group SUq (2) equipped with the four dimensional bicovariant differential calculus of Woronowicz as well as on the quantum homogeneous space S2q with the restricted left covariant three dimensional differential calculus. This is done by giving a family of Hodge dualities on both the exterior algebras of SUq (2) and S2q . We also study gauged Laplacian operators acting on sections of line bundles over the quantum sphere.Comment: v3, one reference corrected, one reference added. 31 page

Gauged Laplacians on quantum Hopf bundles

We study gauged Laplacian operators on line bundles on a quantum 2-dimensional sphere. Symmetry under the (co)-action of a quantum group allows for their complete diagonalization. These operators describe `excitations moving on the quantum sphere' in the field of a magnetic monopole. The energies are not invariant under the exchange monopole/antimonopole, that is under inverting the direction of the magnetic field. There are potential applications to models of quantum Hall effect.Comment: v2: latex; 32 pages. Papers re-organized; no major changes, several minor ones. Commun. Math. Phys. In pres

Linear Algebra and Analytic Geometry for Physical Sciences

This book originates from a collection of lecture notes that the first author prepared at the University of Trieste with Michela Brundu, over a span of fifteen years, together with the more recent one written by the second author. The notes were meant for undergraduate classes on linear algebra, geometry and more generally basic mathematical physics delivered to physics and engineering students, as well as mathematics students in Italy, Germany and Luxembourg. The book is mainly intended to be a self-contained introduction to the theory of finite-dimensional vector spaces and linear transformations (matrices) with their spectral analysis both on Euclidean and Hermitian spaces, to affine Euclidean geometry as well as to quadratic forms and conic sections. Many topics are introduced and motivated by examples, mostly from physics. They show how a definition is natural and how the main theorems and results are first of all plausible before a proof is given. Following this approach, the book presents a number of examples and exercises, which are meant as a central part in the development of the theory. They are all completely solved and intended both to guide the student to appreciate the relevant formal structures and to give in several cases a proof and a discussion, within a geometric formalism, of results from physics, notably from mechanics (including celestial) and electromagnetism

First description of cervical intradural thymoma metastasis

Thymoma and thymic carcinoma are rare epithelial tumors, which originate from the thymus gland. According to the World Health Organization there are "organotypic" (types A, AB, B1, B2, and B3) and "non-organotypic" (thymic carcinomas) thymomas. Type B3 thymomas are aggressive tumors, which can metastasize. Due to the rarity of these lesions, only 7 cases of extradural metastasis are described in the literature. We report the first and unique case of a man with cervical intradural B3 thymoma metastasis. A 46-year-old man underwent thymoma surgical removal. The year after the procedure he was treated for a parietal pleura metastasis. In 2006 he underwent cervical-dorsal extradural metastasis removal and C5-Th1 stabilization. Seven years after he came to our observation complaining left cervicobrachialgia and a reduction of strength of the left arm. He underwent a cervical spine magnetic resonance imaging, which showed a new lesion at the C5-C7 level. The patient underwent a surgery for the intradural B3 thymoma metastasis. Neurological symptoms improved although the removal was subtotal. He went through postoperative radiation therapy with further mass reduction. Spinal metastases are extremely rare. To date, only 7 cases of spinal extradural metastasis have been described in the literature. This is the first case of spinal intradural metastasis. Early individuation of these tumors and surgical treatment improve neurological outcome in patients with spinal cord compression. A multimodal treatment including neoadjuvant chemotherapy, surgery and postoperative radiation therapy seems to improve survival in patients with metastatic thymoma

Motivazione,competenze e produttività del lavoro:Il caso Porto di Carrara S.p.a.

Il presente lavoro ha lo scopo di evidenziare l’importanza del fattore umano all’interno delle aziende, analizzando in modo particolare gli aspetti della motivazione, delle competenze e come questi fattori incidono sulla produttività aziendale. Secondo uno dei principali principi di Total Quality Management, “le persone, a tutti i livelli, costituiscono l’essenza dell’organizzazione, ed il loro pieno coinvolgimento consente di mettere le loro abilità al servizio dell’organizzazione, per un proficuo sviluppo”. Il lavoro è suddiviso in quattro capitoli: nel primo affronto il tema del personale nelle aziende moderne; nel secondo e terzo sviluppo i concetti di motivazione e competenza aziendale all'interno dell'organizzazione e infine nel quarto presento un caso aziendale

Charge Localization in Acene Crystals from Ab Initio Electronic Structure

The performance of Koopmans-compliant hybrid functionals in reproducing the electronic structure of organic crystals is tested for a series of acene crystals. The calculated band gaps are found to be consistent with those achieved with the GW method at a fraction of the computational cost and in excellent accord with the experimental results at room temperature, when including the thermal renormalization. The energetics of excess holes and electrons reveals a struggle between polaronic localization and band-like delocalization. The consequences of these results on the transport properties of acene crystals are discussed

Quantitative Prediction of the Electro-Mechanical Response in Organic Crystals

Organic semiconductors’ inherent flexibility makes them appealing for advanced applications such as wearable electronics, e-skins or pressure sensors and can even be used to enhance their intrinsic electronic properties. Unfortunately, these applications for organic materials are currently hindered by the lack of a quantitative understanding of the interplay between their electrical and mechanical properties. In this work, we fill this gap by presenting an accurate methodology able to predict quantitatively the effects of external deformation on the charge transport properties of any organic semiconductors. Three prototypical materials are investigated, showing that the experimental variation of charge carrier mobility with strain is fully reproduced, even in a wide range of deformations applied along different crystal axes. Our results point out that the intrinsic electro-mechanical response of the materials varies by orders of magnitude within the class of organic semiconductors, a difference rationalized observing that the mobility trend is primarily influenced by transfer integrals’ variation, rather than by a modification of the crystal phonons. In light of its robustness, accuracy and low computational cost, this protocol represents an ideal tool to quantify the electro-mechanical response in new organic compounds, thus establishing a reliable route for a full exploitation of strain engineering in advanced technologies

Explaining different experimental hole mobilities: influence of polymorphism on dynamic disorder in pentacene

The effect of polymorphism (i.e. the ability of accessing different packing structures) on the fluctuations of transfer integrals is quantified for a prototypical molecule, pentacene. Computed mobilities for different polymorphs match the broad range of measured mobilities in organic field-effect transistors (OFET), suggesting that the large spread of experimental values reported in the literature, even when resorting to the same experimental setup, can be related to polymorphism in the samples. This finding is especially significant in new materials, where polymorphism is not known, as it could lead to a spread of results across groups and processing conditions, ultimately slowing down the research towards better semiconductors. Additionally, our analysis shows for the first time that the non-local electron–phonon coupling changes with temperature, a key finding that must be taken into account when computing the temperature dependence of the mobility; it also highlights the possibility of identifying previously unexplored ranges of temperatures, where materials display higher performances. The method here presented can be used to rapidly screen many materials and design new ones thanks to its low computational cost and its accuracy