739 research outputs found

    On the Topology of the Inflaton Field in Minimal Supergravity Models

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    We consider global issues in minimal supergravity models where a single field inflaton potential emerges. In a particular case we reproduce the Starobinsky model and its description dual to a certain formulation of R+R^2 supergravity. For definiteness we confine our analysis to spaces at constant curvature, either vanishing or negative. Five distinct models arise, two flat models with respectively a quadratic and a quartic potential and three based on the SU(1,1)/U(1) space where its distinct isometries, elliptic, hyperbolic and parabolic are gauged. Fayet-Iliopoulos terms are introduced in a geometric way and they turn out to be a crucial ingredient in order to describe the de Sitter inflationary phase of the Starobinsky model.Comment: 31 pages, LaTex, 7 eps figures, 2 table

    The Complete Form of N=2 Supergravity and its Place in the General Framework of D=4 N--Extended Supergravities

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    Relying on the geometrical set up of Special K\"ahler Geometry and Quaternionic Geometry, which I discussed at length in my Lectures at the 1995 edition of this Spring School, I present here the recently obtained fully general form of N=2 supergravity with completely arbitrary couplings. This lagrangian has already been used in the literature to obtain various results: notably the partial breaking of supersymmetry and various extremal black--hole solutions. My emphasis, however, is only on providing the reader with a completely explicit and ready to use component expression of the supergravity action. All the details of the derivation are omitted but all the definitions of the items entering the lagrangian and the supersymmetry transformation rules are given.Comment: 11 pages, LaTeX espcrc2, Seminar at Trieste Spring School 199

    The new types of child maltreatment: a public and social emergency no longer negligible

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    Child abuse and neglect is a common problem that is potentially damaging to long-term physical and psychological health of children. As society and culture have progressively changed different configurations of child abuse and neglect have emerged. Few attention has been focused on these types of child maltreatment that represent the new emergency in this field. Pediatricians should be trained to play a major role in caring for and supporting the social and developmental well-being of children raised in variously conditions and in new types of problems. Pediatric care has been based on the increased awareness of the importance of meeting the psychosocial and developmental needs of children and of the role of families in promoting the health

    Thread-Modular Static Analysis for Relaxed Memory Models

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    We propose a memory-model-aware static program analysis method for accurately analyzing the behavior of concurrent software running on processors with weak consistency models such as x86-TSO, SPARC-PSO, and SPARC-RMO. At the center of our method is a unified framework for deciding the feasibility of inter-thread interferences to avoid propagating spurious data flows during static analysis and thus boost the performance of the static analyzer. We formulate the checking of interference feasibility as a set of Datalog rules which are both efficiently solvable and general enough to capture a range of hardware-level memory models. Compared to existing techniques, our method can significantly reduce the number of bogus alarms as well as unsound proofs. We implemented the method and evaluated it on a large set of multithreaded C programs. Our experiments showthe method significantly outperforms state-of-the-art techniques in terms of accuracy with only moderate run-time overhead.Comment: revised version of the ESEC/FSE 2017 pape

    Static analysis for dummies: experiencing LiSA

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    Semantics-based static analysis requires a significant theoretical background before being able to design and implement a new analysis. Unfortunately, the development of even a toy static analyzer from scratch requires to implement an infrastructure (parser, control flow graphs representation, fixpoint algorithms, etc.) that is too demanding for bachelor and master students in computer science. This approach difficulty can condition the acquisition of skills on software verification which are of major importance for the design of secure systems. In this paper, we show how LiSA (Library for Static Analysis) can play a role in that respect. LiSA implements the basic infrastructure that allows a non-expert user to develop even simple analyses (e.g., dataflow and numerical non-relational domains) focusing only on the design of the appropriate representation of the property of interest and of the sound approximation of the program statements

    Cross-Programming Language Taint Analysis for the IoT Ecosystem

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    The Internet of Things (IoT) is a key component for the next disruptive technologies. However, IoT merges together several diverse software layers: embedded, enterprise, and cloud programs interact with each other. In addition, security and privacy vulnerabilities of IoT software might be particularly dangerous due to the pervasiveness and physical nature of these systems. During the last decades, static analysis, and in particular taint analysis, has been widely applied to detect software vulnerabilities. Unfortunately, these analyses assume that software is entirely written in a single programming language, and they are not immediately suitable to detect IoT vulnerabilities where many different software components, written in different programming languages, interact. This paper discusses how to leverage existing static taint analyses to a cross-programming language scenario

    Static analysis for discovering IoT vulnerabilities

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    The Open Web Application Security Project (OWASP), released the \u201cOWASP Top 10 Internet of Things 2018\u201d list of the high-priority security vulnerabilities for IoT systems. The diversity of these vulnerabilities poses a great challenge toward development of a robust solution for their detection and mitigation. In this paper, we discuss the relationship between these vulnerabilities and the ones listed by OWASP Top 10 (focused on Web applications rather than IoT systems), how these vulnerabilities can actually be exploited, and in which cases static analysis can help in preventing them. Then, we present an extension of an industrial analyzer (Julia) that already covers five out of the top seven vulnerabilities of OWASP Top 10, and we discuss which IoT Top 10 vulnerabilities might be detected by the existing analyses or their extension. The experimental results present the application of some existing Julia\u2019s analyses and their extension to IoT systems, showing its effectiveness of the analysis of some representative case studies

    N=8 gaugings revisited: an exhaustive classification

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    In this paper we reconsider, for N=8 supergravity, the problem of gauging the most general electric subgroup. We show that admissible theories are fully characterized by a single algebraic equation to be satisfied by the embedding of the gauge group G within the electric subalgebra SL(8,\IR) of E_{7(7)}. The complete set of solutions to this equation contains 36 parameters. Modding by the action of SL(8,\IR) conjugations that yield equivalent theories all continuous parameters are eliminated except for an overall coupling constant and we obtain a discrete set of orbits. This set is in one--to--one correspondence with 36 Lie subalgebras of SL(8,\IR), corresponding to all possible real forms of the SO(8) Lie algebra plus a set of contractions thereof. By means of our analysis we establish the theorem that the N=8 gaugings constructed by Hull in the middle eighties constitute the exhaustive set of models. As a corollary we show that there exists a unique 7--dimensional abelian gauging. The corresponding abelian algebra is not contained in the maximal abelian ideal of the solvable Lie algebra generating the scalar manifold E_{7(7)}/SU(8).Comment: 1 LaTeX file, 41 pages, 3 eps-figure
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