Search results for "Pact"
showing 10 items of 2355 documents
Born–Infeld inspired modifications of gravity
2017
General Relativity has shown an outstanding observational success in the scales where it has been directly tested. However, modifications have been intensively explored in the regimes where it seems either incomplete or signals its own limit of validity. In particular, the breakdown of unitarity near the Planck scale strongly suggests that General Relativity needs to be modified at high energies and quantum gravity effects are expected to be important. This is related to the existence of spacetime singularities when the solutions of General Relativity are extrapolated to regimes where curvatures are large. In this sense, Born-Infeld inspired modifications of gravity have shown an extraordin…
Oh, wait, O8 de Sitter may be unstable!
2021
We analyze the stability of four-dimensional de Sitter vacua constructed by compactifying massive Type IIA supergravity in the presence of two O8 sources [1]. When embedded in String Theory the first source has a clear interpretation as an O8$_-$ plane, but the second one could correspond to either an O8$_+$ plane or to an O8$_-$ plane with 16 D8-branes on top. We find that this latter solution has a tachyonic instability, corresponding to the D8-branes moving away from the O8$_-$ plane. We comment on the possible ways of distinguishing between these sources.
Holomorphic Aspects of String Theory
1989
A string is a piecewise smooth map of the interval to a manifold M. A closed string is a map of the circle S1 into M. In string theory the strings replace the points of the manifold M as fundamental objects. The enormous amount of work done on quantized string models in physics has been motivated by the hope that the quantum string theory would produce a finite quantized theory of gravity, free of the divergences of the ordinary quantized Einstein theory of gravitation. So far the proof is missing but work is continuing. It has been proposed that some kind of string theory would be the unified theory of all fundamental interactions in physics. However, the fundamental principles of string t…
The role of transportation and its involved sources of energy in the environmental assessment of marble producing sites
2018
Marble is acquiring large popularity as building material. Since building materials are now required to be characterized by high energy and environmental performances, marble is entailed to fulfill top-level requirements. About its environmental performances an important European Decision establishes criteria for the award of the Community eco-label to this material. Unfortunately, this Decision is focused on mining and processing activities, seemingly neglecting marble transport. In contrast, this phase affects the whole working chain because it releases (pollutant) emissions and involves the use of primary and, in case, secondary energy sources. Here, the focus is on the role played by tr…
Modélisation numérique d’impacts à hautes vitesses par la méthode sans maillage Smoothed Particles Hydrodynamics. Application aux micro-impacts dans …
2021
Investigations on the ballistic behaviours of soft tissue materials are significant research in a medical and pharmaceutical framework. They mainly focus on particles penetrating or traveling into the soft materials. For instance, in the needle-free drug delivery, the micro-scale particles as drug powders are injected into skin with high velocity, and several factors should be considered such as the particle diameters, trajectories, and momentum or velocities of projectile in this process. There have been investigated by some experiments, but there is still no study from the numerical insights.The numerical methods are suitable to study these kinds of processes. Although grid-based methods …
Rolle's Theorem for Polynomials of Degree Four in a Hilbert Space
2002
AbstractIn an infinite-dimensional real Hilbert space, we introduce a class of fourth-degree polynomials which do not satisfy Rolle's Theorem in the unit ball. Extending what happens in the finite-dimensional case, we show that every fourth-degree polynomial defined by a compact operator satisfies Rolle's Theorem.
Le droit privé de la Révolution : héritage législatif et héritage idéologique
2002
Jean-Louis Halpérin, Private Law and the Revolution : Legislative Heritage and Ideological Heritage. The private law of the French Revolution is to-day no longer considered an intermediary law. Yet from a positivist point of view, most of the provisions enacted in this area between 1788 to 1799 were of short duration. Indeed, a large part of revolutionary private law is made up of bills and drafts which were never implemented. This singularity invites us to ponder the legal ideological nature of a law which barely left the drawing-board and its impact in France and abroad.
Let the best story win : evaluation of the most cited business history articles
2017
Faced with intensifying competition for scientific impact measured in terms of citation counts, small disciplines are challenged to prove their importance as they lack the critical mass to accumulate large numbers of citations. This paper demonstrates that by emphasizing theoretical and methodological rigor even small disciplines such as business history can be competitive. Yet it still appears that readers of business history articles first and foremost seek interesting and useful subject matter, i.e. ‘best’ stories that can be used as background information and as tools in comparisons. However, articles advancing theory and methodology have increasingly gained interest and citations from …
Towards an environmental assessment model of palaeontological and archaeological heritage in the Autonomous Valencian Community without comparative t…
2019
The deficient management of the paleontological heritage through the environmental impact assessment procedures from the Valencian public administrations, linked mainly to the lack of competent technical means in the matter, results in an almost abandonment of it. On the contrary, the archaeological heritage has a series of perfectly structured tools that allow any possible impact on it regarding projects and actions subject to environmental impact assessment that can be detected and corrected. The damage that this situation creates results in the abandonment and almost absolute lack of protection of the palaeontological heritage in the Valencian Community. Despite how much has been written…
Catalunya i València durant la Guerra de Successió. «La comuna empresa de la llibertat»
2012
La mort sense descendència de Carles II situava Europa i la Monarquia Hispànica en una autèntica cruïlla. Els dos candidats finals al tron, l'arxiduc Carles d'Àustria i el duc d'Anjou, Felip de Borbó, representaven trajectòries politicodinàstiques ben diferents. Per als Regnes de la Corona d'Aragó, estava en joc la pervivència del sistema pactista i la defensa dels seus projectes i interessos econòmics. En aquest context, Catalunya i València mantingueren una relació ben estreta, d'ajuda mútua, durant l'etapa de govern austriacista, que continuà després de la victòria borbònica d'Almansa i de l'abolició dels Furs de València, en un intent de frenar l'ofensiva militar sobre Catalunya i de re…