1,185 research outputs found

    On the Hilbert scheme of curves in higher-dimensional projective space

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    In this paper we prove that, for any nā‰„3n\ge 3, there exist infinitely many rāˆˆNr\in \N and for each of them a smooth, connected curve CrC_r in Ā¶r\P^r such that CrC_r lies on exactly nn irreducible components of the Hilbert scheme \hilb(\P^r). This is proven by reducing the problem to an analogous statement for the moduli of surfaces of general type.Comment: latex, 12 pages, no figure

    Smoothing semi-smooth stable Godeaux surfaces

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    We show that all the semi-smooth stable complex Godeaux surfaces, classified in [M. Franciosi, R. Pardini and S. Rollenske, Ark. Mat. 56 (2018), no. 2, 299ā€“317], are smoothable and that the moduli stack is smooth of the expected dimension 8 at the corresponding points

    The Sensoria Approach Applied to the Finance Case Study

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    This chapter provides an effective implementation of (part of) the Sensoria approach, specifically modelling and formal analysis of service-oriented software based on mathematically founded techniques. The ā€˜Finance case studyā€™ is used as a test bed for demonstrating the feasibility and effectiveness of the use of the process calculus COWS and some of its related analysis techniques and tools. In particular, we report the results of an application of a temporal logic and its model checker for expressing and checking functional properties of services and a type system for guaranteeing confidentiality properties of services

    The Drinfel'd Double and Twisting in Stringy Orbifold Theory

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    This paper exposes the fundamental role that the Drinfel'd double \dkg of the group ring of a finite group GG and its twists \dbkg, \beta \in Z^3(G,\uk) as defined by Dijkgraaf--Pasquier--Roche play in stringy orbifold theories and their twistings. The results pertain to three different aspects of the theory. First, we show that GG--Frobenius algebras arising in global orbifold cohomology or K-theory are most naturally defined as elements in the braided category of \dkg--modules. Secondly, we obtain a geometric realization of the Drinfel'd double as the global orbifold KK--theory of global quotient given by the inertia variety of a point with a GG action on the one hand and more stunningly a geometric realization of its representation ring in the braided category sense as the full KK--theory of the stack [pt/G][pt/G]. Finally, we show how one can use the co-cycles Ī²\beta above to twist a) the global orbifold KK--theory of the inertia of a global quotient and more importantly b) the stacky KK--theory of a global quotient [X/G][X/G]. This corresponds to twistings with a special type of 2--gerbe.Comment: 35 pages, no figure

    A Logical Verification Methodology for Service-Oriented Computing

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    We introduce a logical verification methodology for checking behavioural properties of service-oriented computing systems. Service properties are described by means of SocL, a branching-time temporal logic that we have specifically designed to express in an effective way distinctive aspects of services, such as, e.g., acceptance of a request, provision of a response, and correlation among service requests and responses. Our approach allows service properties to be expressed in such a way that they can be independent of service domains and specifications. We show an instantiation of our general methodology that uses the formal language COWS to conveniently specify services and the expressly developed software tool CMC to assist the user in the task of verifying SocL formulae over service specifications. We demonstrate feasibility and effectiveness of our methodology by means of the specification and the analysis of a case study in the automotive domain

    Chen-Ruan cohomology of ADE singularities

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    We study Ruan's \textit{cohomological crepant resolution conjecture} for orbifolds with transversal ADE singularities. In the AnA_n-case we compute both the Chen-Ruan cohomology ring HCRāˆ—([Y])H^*_{\rm CR}([Y]) and the quantum corrected cohomology ring Hāˆ—(Z)(q1,...,qn)H^*(Z)(q_1,...,q_n). The former is achieved in general, the later up to some additional, technical assumptions. We construct an explicit isomorphism between HCRāˆ—([Y])H^*_{\rm CR}([Y]) and Hāˆ—(Z)(āˆ’1)H^*(Z)(-1) in the A1A_1-case, verifying Ruan's conjecture. In the AnA_n-case, the family Hāˆ—(Z)(q1,...,qn)H^*(Z)(q_1,...,q_n) is not defined for q1=...=qn=āˆ’1q_1=...=q_n=-1. This implies that the conjecture should be slightly modified. We propose a new conjecture in the AnA_n-case which we prove in the A2A_2-case by constructing an explicit isomorphism.Comment: This is a short version of my Ph.D. Thesis math.AG/0510528. Version 2: chapters 2,3,4 and 5 has been rewritten using the language of groupoids; a link with the classical McKay correpondence is given. International Journal of Mathematics (to appear

    Specifying and Analysing SOC Applications with COWS

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    COWS is a recently defined process calculus for specifying and combining service-oriented applications, while modelling their dynamic behaviour. Since its introduction, a number of methods and tools have been devised to analyse COWS specifications, like e.g. a type system to check confidentiality properties, a logic and a model checker to express and check functional properties of services. In this paper, by means of a case study in the area of automotive systems, we demonstrate that COWS, with some mild linguistic additions, can model all the phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, orchestration, deployment, reconfiguration and execution. We also provide a flavour of the properties that can be analysed by using the tools mentioned above

    GPU-based Real-time Triggering in the NA62 Experiment

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    Over the last few years the GPGPU (General-Purpose computing on Graphics Processing Units) paradigm represented a remarkable development in the world of computing. Computing for High-Energy Physics is no exception: several works have demonstrated the effectiveness of the integration of GPU-based systems in high level trigger of different experiments. On the other hand the use of GPUs in the low level trigger systems, characterized by stringent real-time constraints, such as tight time budget and high throughput, poses several challenges. In this paper we focus on the low level trigger in the CERN NA62 experiment, investigating the use of real-time computing on GPUs in this synchronous system. Our approach aimed at harvesting the GPU computing power to build in real-time refined physics-related trigger primitives for the RICH detector, as the the knowledge of Cerenkov rings parameters allows to build stringent conditions for data selection at trigger level. Latencies of all components of the trigger chain have been analyzed, pointing out that networking is the most critical one. To keep the latency of data transfer task under control, we devised NaNet, an FPGA-based PCIe Network Interface Card (NIC) with GPUDirect capabilities. For the processing task, we developed specific multiple ring trigger algorithms to leverage the parallel architecture of GPUs and increase the processing throughput to keep up with the high event rate. Results obtained during the first months of 2016 NA62 run are presented and discussed
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