23,179 research outputs found
On the weak field approximation of Brans-Dicke theory of gravity
It is shown that in the weak field approximation solutions of Brans-Dicke
equations are simply related to the solutions of General Relativity equations
for the same matter distribution. A simple method is developed which permits to
obtain Brans-Dicke solutions from Einstein solutions when both theories are
considered in their linearized forms. To illustrate the method some examples
found in the literature are discussed.Comment: 12 pages, latex, no figure
Network Information Flow in Small World Networks
Recent results from statistical physics show that large classes of complex
networks, both man-made and of natural origin, are characterized by high
clustering properties yet strikingly short path lengths between pairs of nodes.
This class of networks are said to have a small-world topology. In the context
of communication networks, navigable small-world topologies, i.e. those which
admit efficient distributed routing algorithms, are deemed particularly
effective, for example in resource discovery tasks and peer-to-peer
applications. Breaking with the traditional approach to small-world topologies
that privileges graph parameters pertaining to connectivity, and intrigued by
the fundamental limits of communication in networks that exploit this type of
topology, we investigate the capacity of these networks from the perspective of
network information flow. Our contribution includes upper and lower bounds for
the capacity of standard and navigable small-world models, and the somewhat
surprising result that, with high probability, random rewiring does not alter
the capacity of a small-world network.Comment: 23 pages, 8 fitures, submitted to the IEEE Transactions on
Information Theory, November 200
Beyond the quantum formalism: consequences of a neural-oscillator model to quantum cognition
In this paper we present a neural oscillator model of stimulus response
theory that exhibits quantum-like behavior. We then show that without adding
any additional assumptions, a quantum model constructed to fit observable
pairwise correlations has no predictive power over the unknown triple moment,
obtainable through the activation of multiple oscillators. We compare this with
the results obtained in de Barros (2013), where a criteria of rationality gives
optimal ranges for the triple moment.Comment: 4 pages; to appear in the Advances in Cognitive Neurodynamics,
Proceedings of the 4th International Conference on Cognitive Neurodynamics -
201
Remedy for Now but Prohibit for Tomorrow: The Deterrence Effects of Merger Policy Tools
Antitrust policy involves not just the regulation of anti-competitive behavior, but also an important deterrence effect. Neither scholars nor policymakers have fully researched the deterrence effects of merger policy tools, as they have been unable to empirically measure these effects. We consider the ability of different antitrust actions â Prohibitions, Remedies, and Monitorings â to deter firms from engaging in mergers. We employ cross-jurisdiction/pan-time data on merger policy to empirically estimate the impact of antitrust actions on future merger frequencies. We find merger prohibitions to lead to decreased merger notifications in subsequent periods, and remedies to weakly increase future merger notifications: in other words, prohibitions involve a deterrence effect but remedies do not
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