15,016 research outputs found
Can modified gravity models reconcile the tension between CMB anisotropy and lensing maps in Planck-like observations?
Planck-2015 data seem to favour a large value of the lensing amplitude
parameter, , in CMB spectra. This result is in
tension with the lensing reconstruction result, . In this paper, we simulate several CMB anisotropy
and CMB lensing spectra based on Planck-2015 best-fit cosmological parameter
values and Planck blue book beam and noise specifications. We analyse several
modified gravity models within the effective field theory framework against
these simulations and find that models whose effective Newton constant is
enhanced can modulate the CMB anisotropy spectra in a way similar to that of
the parameter. However, in order to lens the CMB anisotropies
sufficiently, like in the Planck-2015 results, the growth of matter
perturbations is substantially enhanced and gives a high value. This
in turn proves to be problematic when combining these data to other probes,
like weak lensing from CFHTLenS, that favour a smaller amplitude of matter
fluctuations.Comment: 7 pages, 3 figure
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An Exploration into the Use of Scordatura Tuning to Perform J. S. Bach's Partita BWV 1004 on the Guitar
J. S. Bach’s solo string and lute works have become an indispensable part of the modern guitar repertoire. While the tonal character of the modern guitar, being closely related to the Baroque guitar and lute, is fitting for Baroque performance practice, the instrument was not directly associated with Bach’s compositional idioms as he did not play it nor compose for it. Therefore, the renditions of Bach’s works on the modern guitar expose a series of technical and stylistic problems, with the majority of the problems being a result of the tuning structure of the guitar. This study investigates the use of a lute-inspired scordatura (hereinafter referred to as semi-lute scordatura) on the guitar to: (1) simplify technical difficulties by promoting the use of lower positions and open strings, (2) embody the stylistic features of the lute and harpsichord, and (3) incorporate ornamental practices from the lute and harpsichord. The Violin Partita BWV 1004 has been used in this document as a model to demonstrate the outstanding features that the semi-lute scordatura provides in these respects. The results of this study not only inform guitarists of the possibility to perform Bach’s music with scordatura tuning, but more importantly, they also expose guitarists to the lute and harpsichord style to ultimately provide essential knowledge that can be applied to create a historically-inspired rendition of Bach’s music on the guitar, even with standard tuning
Cellular-Automata Based Qualitative Simulation for Nonprofit Group Behavior
A cellular automata based qualitative simulation of group behavior (referred hitherto as \'loyalty to group\') will be presented by integrating QSIM (Qualitative SIMulation) and CA (Cellular Automata) modeling. First, we provide a breakdown of the structure of a group and offer an analysis of how this structure impacts behavior. The characteristics and impact had by anomalies within a group and by environmental factors are also explored. Second, we explore the transition between cause and effect (referred hitherto as the \'transition rule\') and the change in behavior that is the result of this transition (referred hitherto as the \'successor behavior state\'). A filter for weeding out anomalies is then proposed. The simulation engine is then used integrating all relevant data as outlined above. A concept referred to as the \'Loyalty-cost equilibrium\' is presented and factored into the filter. Third, the validity of this method is tested by running the simulation using eight generalized examples. The input-output of each simulation run using these examples is consistent with what can reasonably be accepted to be true, thus demonstrating that the proposed method is valid. At this point we illustrate how the simulation is applied in context. Simulation outputs (effect on group behavior) at each time stage of two alternating changes in policy are compared to determine which policy would be the most advantageous. This demonstrates that this method serves as reliable virtual tool in the decision making difficulties of group management.Cellular Automata; Qualitative Simulation; Group Behavior; Loyalty-Cost Equilibrium; Loyalty Gravitation; Cost Gravitation
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