oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

时间不限

2018 ( 1 )

2017 ( 72 )

2016 ( 53 )

2015 ( 926 )

自定义范围…

匹配条件: “Stéphane Le Corre” ,找到相关结果约21467条。
列表显示的所有文章,均可免费获取
第1页/共21467条
每页显示
Dark matter, a new proof of the predictive power of general relativity
Stéphane Le Corre
Physics , 2015,
Abstract: Without observational or theoretical modifications, Newtonian and general relativity seem to be unable to explain gravitational behavior of large structure of the universe. The assumption of dark matter solves this problem without modifying theories. But it implies that most of the matter in the universe must be unobserved matter. Another solution is to modify gravitation laws. In this article, we study a third way that doesn't modify gravitation neither matter's distribution, by using a new physical assumption on the clusters. Compare with Newtonian gravitation, general relativity (in its linearized approximation) leads to add a new component without changing the gravity field. As already known, this component for galaxies is too small to explain dark matter. But we will see that the galaxies' clusters can generate a significant component and embed large structure of universe. We show that the magnitude of this embedding component is small enough to be in agreement with current experimental results, undetectable at our scale, but detectable at the scale of the galaxies and explain dark matter, in particular the rotation speed of galaxies, the rotation speed of dwarf satellite galaxies, the expected quantity of dark matter inside galaxies and the expected experimental values of parameters $\Omega$\_dm of dark matter measured in CMB. This solution implies testable consequences that differentiate it from other theories: decreasing dark matter with the distance to the cluster's center, large quantity of dark matter for galaxies close to the cluster's center, isolation of galaxies without dark matter, movement of dwarf satellite galaxies in planes close to the supergalactic plane, close orientations of spin's vectors of two close clusters, orientation of nearly all the spin's vector of galaxies of a same cluster in a same half-space, existence of very rare galaxies with two portions of their disk that rotate in opposite directions...
Dark Matter without New Matter Is Compliant with General Relativity  [PDF]
Stéphane Le Corre
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1103877
Abstract:
A recent publication revealed unexpected observations about dark matter. In particular, the observed baryonic mass should probably be sufficient to explain the observed rotation curves (i.e. without dark matter) and their observations gave an empirical relation for weak accelerations. This present work demonstrated that the equations of general relativity allow explaining the term of dark matter (without new matter) in agreement with the results of this publication and allow retrieving this empirical relation (observed values and characteristics of this correlation’s curve). These observations constrain drastically the possible gravitational potential in the frame of general relativity to explain the term of dark matter. This theoretical solution has already been studied with several unexpected predictions that have recently been observed. For example, an article revealed that early galaxies (ten billion years ago) didn’t have dark matter and a more recent paper showed unlikely alignments of galaxies. To finish the main prediction of this solution, it is recalled: the term of dark matter should be a Lense-Thirring effect, around the earth, of around 0.3 and 0.6 milliarcsecond/year.
Dark Matter, a Direct Detection  [PDF]
Stéphane Le Corre
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1104219
Abstract:
In a previous paper, we demonstrated that the linearized general relativity could explain dark matter (the rotation speed of galaxies, the rotation speed of dwarf satellite galaxies, the movement in a plane of dwarf satellite galaxies, the decreasing quantity of dark matter with the distance to the center of galaxies’ cluster, the expected quantity of dark matter inside galaxies and the expected experimental values of parameters Ωdm of dark matter measured in CMB). It leads, compared with Newtonian gravitation, to taking in account the second component (gravitational field) of the gravitation (imposed by general relativity) without changing the gravity field (also known as gravitomagnetism). In this explanation, dark matter would be a uniform gravitational field that embeds some very large areas of the universe generated by the clusters. In this article we are going to see that this specific gravitational field, despite its weakness, could be soon detectable, allowing testing this explanation of dark matter. It should generate a slight discrepancy in the expected measure of the Lense-Thirring effect of the Earth. In this theoretical frame, the Lense-Thirring effect of the “dark matter” would be a value between around 0.3 milliarcsecond/year and 0.6 milliarcsecond/year in the best case. In the LAGEOS or Gravity Probe B experiments, there was not enough precision (around 0.3% for the expected 6606 mas·y﹣1 geodetic and around 19% for the expected 39 mas·y﹣1 frame-dragging precessions). In the GINGER experiment, there could be enough one; the expected accuracy would be around 1%. If this discrepancy was verified, it would be the first direct measure of the dark matter.
About the Negative Gravitational Mass  [PDF]
Stéphane Le Corre
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104312
Abstract:
In a previous paper, we demonstrated that the linearized general relativity could explain dark energy (the experimental values of parameters ΩΛ, the cosmological constant, the recent acceleration of the expansion of our Universe) offering an amazing image of our universe at an incredible scale. This explanation of dark energy relies on the assumption of the existence of a negative gravitational mass (with always a positive inertial mass meaning that gravitation could be repulsive). This article demonstrates that this assumption is not only compliant with general relativity but even that the repulsive gravitational interaction is inscribed in the equations of the general relativity. The absence of negative gravitational mass should then be justified because nothing forbids its existence and until now repulsive gravitation has never been observed. This natural possibility of general relativity must be then avoided by adding an ad hoc paradigm. In a way, the principle of masses’ equivalence plays indirectly this role. We will show why this principle can be verified with a great accuracy but we also propose experiments that could violate this principle, allowing at the same time rejecting its status of theoretical principle. This frame of explanation (general relativity released from this ad hoc constraint) opened then the way of the negative gravitational mass with its natural corollary, the repulsive gravitational interaction, and of the following major predictions: the antimatter should have a negative gravitational mass, the neutrino should not be a Majorana particle, the principle of equivalence of masses should be violated for the antiprotonic helium, the apparent disappearance of antimatter could be explained. We recall some other consequences: an “initial” cosmic inflation would be unavoidable, dark energy (or cosmological constant) might not be constant in time (causing accelerating universe). Several experiments are testing some of these predictions: NEMO experiment tests if neutrino is a Majorana particle, and AEgIS, ALPHA and GBAR experiments at CERN test the behavior of the gravitational interaction on anti-matter and the sign of its gravitational mass. First results could be obtained in 2018. Experiments are proposed to test the violation of the principle of equivalence of the masses.
La lutte continue
Stéphane Le?Lay
Variations : Revue Internationale de Théorie Critique , 2012,
Abstract: Mai 1968 semble être sur toutes les lèvres et dans tous les esprits ces derniers jours. On ne compte plus les sorties d’ouvrages sur la question, plus ou moins opportunistes. La tonalité des débats oscille généralement entre deux extrêmes : d’un c té, la nostalgie d’une époque où l’espoir portait la puissance de devenirs meilleurs, car moins compassés et rigides ; de l’autre, la reconnaissance d’un ensemble de phénomènes à l’existence historique indéniable, mais désormais révolue voire à liqu...
Mètis et rire. Que nous apprennent les petits éboueurs ?
Stéphane Le?Lay
Variations : Revue Internationale de Théorie Critique , 2012,
Abstract: Lors d’un colloque récent consacré aux métiers du nettoiement et à la gestion des déchets dans l’espace public, la majorité des intervenants, sinon tous, partageaient l’idée selon laquelle travailler sur de telles questions permettait d’étudier des problèmes fondamentaux et passionnants, au prix d’un certain risque de mise à l’écart académique. D’un point de vue symbolique (et spatial, si l’on considère les dynamiques du champ académique que cela implique), le chercheur paierait de fait son t...
Des pratiques ouvrières ludiques aux dispositifs managériaux ludistes : vers une instrumentalisation du jeu dans le travail Playful worker practices in playful managerial system: towards an instrumentalisation of games in the world of work De las prácticas obreras lúdicas a los dispositivos gerenciales ludistas : hacia una instrumentalización del juego en el trabajo
Stéphane Le Lay
La Nouvelle Revue du Travail , 2013,
Abstract: De nombreux auteurs ont décrit et analysé le jeu sous l’angle des pratiques ouvrières résistancielles ou subversives renseignant sur l’autonomie du collectif face à l’organisation du travail. En partant de telles réflexions ancrées sur deux terrains empiriques contrastés (un atelier d’éboueurs, un centre d’appels téléphoniques), on s’interrogera sur les implications, au niveau des salarié·e·s, d’une utilisation, par les managers, de dispositifs ludiques visant à accentuer l’implication au travail. Many authors have described and analyzed games as resistant or subversive work practices providing information about the kind of autonomy that a group will manifest in its dealings with a work organisation. Starting with this kind of thinking – embedded in two contrasting empirical foundations (a streetsweeping depot, a call centre), the focus here is on the implications for employees – and on how managers use – “playful” mechanisms aimed at getting people more involved in their work. Muchos autores han descrito y analizado el juego desde la óptica de las prácticas obreras de resistencia o subversivas que arrojan información sobre la autonomía de lo colectivo frente a la organización del trabajo. Partiendo de esas reflexiones ancladas en dos terrenos empíricos contrastados (un taller de barrenderos, un centro de atención telefónica), nos interrogaremos sobre las implicaciones para los asalariados de una utilización por los directivos de dispositivos “lúdicos” que buscan acentuar la implicación en el trabajo.
From winning strategy to Nash equilibrium
Stéphane Le Roux
Mathematics , 2012,
Abstract: Game theory is usually considered applied mathematics, but a few game-theoretic results, such as Borel determinacy, were developed by mathematicians for mathematics in a broad sense. These results usually state determinacy, i.e. the existence of a winning strategy in games that involve two players and two outcomes saying who wins. In a multi-outcome setting, the notion of winning strategy is irrelevant yet usually replaced faithfully with the notion of (pure) Nash equilibrium. This article shows that every determinacy result over an arbitrary game structure, e.g. a tree, is transferable into existence of multi-outcome (pure) Nash equilibrium over the same game structure. The equilibrium-transfer theorem requires cardinal or order-theoretic conditions on the strategy sets and the preferences, respectively, whereas counter-examples show that every requirement is relevant, albeit possibly improvable. When the outcomes are finitely many, the proof provides an algorithm computing a Nash equilibrium without significant complexity loss compared to the two-outcome case. As examples of application, this article generalises Borel determinacy, positional determinacy of parity games, and finite-memory determinacy of Muller games.
Graphs and Path Equilibria
Stéphane Le Roux
Computer Science , 2007,
Abstract: The quest for optimal/stable paths in graphs has gained attention in a few practical or theoretical areas. To take part in this quest this chapter adopts an equilibrium-oriented approach that is abstract and general: it works with (quasi-arbitrary) arc-labelled digraphs, and it assumes very little about the structure of the sought paths and the definition of equilibrium, \textit{i.e.} optimality/stability. In this setting, this chapter presents a sufficient condition for equilibrium existence for every graph; it also presents a necessary condition for equilibrium existence for every graph. The necessary condition does not imply the sufficient condition a priori. However, the chapter pinpoints their logical difference and thus identifies what work remains to be done. Moreover, the necessary and the sufficient conditions coincide when the definition of optimality relates to a total order, which provides a full-equivalence property. These results are applied to network routing.
Discrete Nondeterminism and Nash Equilibria for Strategy-Based Games
Stéphane Le Roux
Computer Science , 2007,
Abstract: Several notions of game enjoy a Nash-like notion of equilibrium without guarantee of existence. There are different ways of weakening a definition of Nash-like equilibrium in order to guarantee the existence of a weakened equilibrium. Nash's approach to the problem for strategic games is probabilistic, \textit{i.e.} continuous, and static. CP and BR approaches for CP and BR games are discrete and dynamic. This paper proposes an approach that lies between those two different approaches: a discrete and static approach. multi strategic games are introduced as a formalism that is able to express both sequential and simultaneous decision-making, which promises a good modelling power. multi strategic games are a generalisation of strategic games and sequential graph games that still enjoys a Cartesian product structure, \textit{i.e.} where agent actually choose their strategies. A pre-fixed point result allows guaranteeing existence of discrete and non deterministic equilibria. On the one hand, these equilibria can be computed with polynomial (low) complexity. On the other hand, they are effective in terms of recommendation, as shown by a numerical example.
第1页/共21467条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.