377 research outputs found

    Evolutionary instability of Zero Determinant strategies demonstrates that winning isn't everything

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    Zero Determinant (ZD) strategies are a new class of probabilistic and conditional strategies that are able to unilaterally set the expected payoff of an opponent in iterated plays of the Prisoner's Dilemma irrespective of the opponent's strategy, or else to set the ratio between a ZD player's and their opponent's expected payoff. Here we show that while ZD strategies are weakly dominant, they are not evolutionarily stable and will instead evolve into less coercive strategies. We show that ZD strategies with an informational advantage over other players that allows them to recognize other ZD strategies can be evolutionarily stable (and able to exploit other players). However, such an advantage is bound to be short-lived as opposing strategies evolve to counteract the recognition.Comment: 14 pages, 4 figures. Change in title (again!) to comply with Nature Communications requirements. To appear in Nature Communication

    Emotions and ethics: A Foucauldian framework for becoming an ethical educator

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    This paper provides examples of how a teacher and a principal construct their ‘ethical selves’. In doing so we demonstrate how Foucault's four-part ethical framework can be a scaffold with which to actively connect emotions to a personal ethical position. We argue that ethical work is and should be an ongoing and dynamic life long process rather than a more rigid adherence to a ‘code of ethics’ that may not meaningfully engage its adherents. We use Foucault's four-part framework of ethical practice as a framework through which an ‘ethical self’ can be purposely constructed. This is important work, as those who have authority over others must know how to monitor themselves against the misuse of the power of their positions

    Microwave Spectroscopy

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    Contains reports on five research projects.United States Army Signal Corps (Contract DA36-039-sc-87376

    Microwave Spectroscopy

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    Contains reports on four research projects

    Radiative decay of a massive particle and the non-thermal process in primordial nucleosynthesis

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    We consider the effects on big bang nucleosynthesis (BBN) of the radiative decay of a long-lived massive particle. If high-energy photons are emitted after the BBN epoch (t1103t \sim 1 - 10^3 sec), they may change the abundances of the light elements through photodissociation processes, which may result in a significant discrepancy between standard BBN and observation. Taking into account recent observational and theoretical developments in this field, we revise our previous study constraining the abundance of the radiatively-decaying particles. In particular, on the theoretical side, it was recently claimed that the non-thermal production of 6^6Li, which is caused by the photodissociation of \hefour, most severely constrains the abundance of the radiatively-decaying particle. We will see, however, it is premature to emphasize the importance of the non-thermal production of 6^6Li because (i) the theoretical computation of the 6^6Li abundance has large uncertainty due to the lack of the precise understanding of the 6^6Li production cross section, and (ii) the observational data of 6^6Li abundance has large errors.Comment: 15 pages, using REVTeX and 3 postscript figure

    Radiative Decay of a Long-Lived Particle and Big-Bang Nucleosynthesis

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    The effects of radiatively decaying, long-lived particles on big-bang nucleosynthesis (BBN) are discussed. If high-energy photons are emitted after BBN, they may change the abundances of the light elements through photodissociation processes, which may result in a significant discrepancy between the BBN theory and observation. We calculate the abundances of the light elements, including the effects of photodissociation induced by a radiatively decaying particle, but neglecting the hadronic branching ratio. Using these calculated abundances, we derive a constraint on such particles by comparing our theoretical results with observations. Taking into account the recent controversies regarding the observations of the light-element abundances, we derive constraints for various combinations of the measurements. We also discuss several models which predict such radiatively decaying particles, and we derive constraints on such models.Comment: Published version in Phys. Rev. D. Typos in figure captions correcte

    Microwave Spectroscopy

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    Contains reports on four research projects

    Microwave Spectroscopy

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    Contains research objectives and reports on five research projects.Signal Corps Contract DA36-039-sc-73014Signal Corps Contract DA36-039-sc-7489
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