12,172 research outputs found

    Private Data System Enabling Self-Sovereign Storage Managed by Executable Choreographies

    Full text link
    With the increased use of Internet, governments and large companies store and share massive amounts of personal data in such a way that leaves no space for transparency. When a user needs to achieve a simple task like applying for college or a driving license, he needs to visit a lot of institutions and organizations, thus leaving a lot of private data in many places. The same happens when using the Internet. These privacy issues raised by the centralized architectures along with the recent developments in the area of serverless applications demand a decentralized private data layer under user control. We introduce the Private Data System (PDS), a distributed approach which enables self-sovereign storage and sharing of private data. The system is composed of nodes spread across the entire Internet managing local key-value databases. The communication between nodes is achieved through executable choreographies, which are capable of preventing information leakage when executing across different organizations with different regulations in place. The user has full control over his private data and is able to share and revoke access to organizations at any time. Even more, the updates are propagated instantly to all the parties which have access to the data thanks to the system design. Specifically, the processing organizations may retrieve and process the shared information, but are not allowed under any circumstances to store it on long term. PDS offers an alternative to systems that aim to ensure self-sovereignty of specific types of data through blockchain inspired techniques but face various problems, such as low performance. Both approaches propose a distributed database, but with different characteristics. While the blockchain-based systems are built to solve consensus problems, PDS's purpose is to solve the self-sovereignty aspects raised by the privacy laws, rules and principles.Comment: DAIS 201

    Singularity Theory in Classical Cosmology

    Full text link
    This paper compares recent approaches appearing in the literature on the singularity problem for space-times with nonvanishing torsion.Comment: 4 pages, plain-tex, published in Nuovo Cimento B, volume 107, pages 849-851, year 199

    Novel features of the energy momentum tensor of a Casimir apparatus in a weak gravitational field

    Full text link
    The influence of the gravity acceleration on the regularized energy-momentum tensor of the quantized electromagnetic field between two plane parallel conducting plates is derived. A perturbative expansion, to first order in the constant acceleration parameter, of the Green functions involved and of the energy-momentum tensor is derived by means of the covariant geodesic point splitting procedure. The energy-momentum tensor is covariantly conserved and satisfies the expected relation between gauge-breaking and ghost parts.Comment: 8 pages, based on a talk given by Luigi Rosa at the QFEXT07 Conference, Leipzig. Equation (13) and the formulae for rho and energy E stored in the Casimir device have been amended, jointly with related discussio

    Beta decays with momentum space Majorana spinors

    Full text link
    We construct and apply to beta decays a truly neutral local quantum field that is entirely based upon momentum space Majorana spinors. We make the observation that theory with momentum space Majorana spinors of real C parities is equivalent to Dirac's theory. For imaginary C parities, the neutrino mass can drop from the single beta decay trace and reappear in 0\nu \beta \beta, a curious and in principle experimentally testable signature for a non-trivial impact of Majorana framework in experiments with polarized sources.Comment: 7 pages, 1 figure; needs svjour.cls, svepj.cl

    New Developments in the Spectral Asymptotics of Quantum Gravity

    Full text link
    A vanishing one-loop wave function of the Universe in the limit of small three-geometry is found, on imposing diffeomorphism-invariant boundary conditions on the Euclidean 4-ball in the de Donder gauge. This result suggests a quantum avoidance of the cosmological singularity driven by full diffeomorphism invariance of the boundary-value problem for one-loop quantum theory. All of this is made possible by a peculiar spectral cancellation on the Euclidean 4-ball, here derived and discussed.Comment: 7 pages, latex file. Paper prepared for the Conference "QFEXT05: Quantum Field Theory Under the Influence of External Conditions", Barcelona, September 5 - September 9, 2005. In the final version, the presentation has been further improved, and yet other References have been adde

    The Neumann eigenvalue problem for the \infty-Laplacian

    Full text link
    The first nontrivial eigenfunction of the Neumann eigenvalue problem for the pp-Laplacian, suitable normalized, converges as pp goes to \infty to a viscosity solution of an eigenvalue problem for the \infty-Laplacian. We show among other things that the limit of the eigenvalue, at least for convex sets, is in fact the first nonzero eigenvalue of the limiting problem. We then derive a number of consequences, which are nonlinear analogues of well-known inequalities for the linear (2-)Laplacian.Comment: Corrected few typos. Corollary 5 adde
    corecore