3,490 research outputs found

    Institutional structures and processes for environmental planning and management of the peri-urban interface

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    Strategies are needed which deal not only with urban impacts but also with the transitional nature of activities in the zone, once urban impacts are felt. And there are strategies for rural activities to exploit their proximity to towns and cities. Yet these strategies must be matched to the limited capacities of the institutions available for formulating and implementing them if they are to be effective. Alternatively, institutions can be given new capacities or new relationships

    Low energy bounds on Poincare violation in causal set theory

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    In the causal set approach to quantum gravity, Poincar\'{e} symmetry is modified by swerving in spacetime, induced by the random lattice discretization of the space-time structure. The broken translational symmetry at short distances is argued to lead to a residual diffusion in momentum space, whereby a particle can acquire energy and momentum by drift along its mass shell and a system in equilibrium can spontaneously heat up. We consider bounds on the rate of momentum space diffusion coming from astrophysical molecular clouds, nuclear stability and cosmological neutrino background. We find that the strongest limits come from relic neutrinos, which we estimate to constrain the momentum space diffusion constant by k<1061GeV3k < 10^{-61} {\rm GeV}^3 for neutrinos with masses mν>0.01eVm_\nu > 0.01 {\rm eV}, improving the previously quoted bounds by roughly 17 orders of magnitude.Comment: Additional discussion about behavior of alpha particles in nuclei added. Version matches that accepted in PR

    The strong Feller property for singular stochastic PDEs

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    We show that the Markov semigroups generated by a large class of singular stochastic PDEs satisfy the strong Feller property. These include for example the KPZ equation and the dynamical Φ34\Phi^4_3 model. As a corollary, we prove that the Brownian bridge measure is the unique invariant measure for the KPZ equation with periodic boundary conditions

    An Examination of Relational-interdependent Self-construal, Communal Strength, and Pro-relationship Behaviors in Friendships

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    Individual differences in relational-interdependent self-construal (RISC) are associated with positive relationship characteristics. This suggests that RISC is positively associated with the degree to which individuals view their relationships as communally-oriented (i.e., governed by norms of responsiveness), which should in turn be associated with increased use of pro-relationship behaviors. Thus, the current study explored the associations between RISC, communal strength, and pro-relationship behaviors in friendships. As predicted, RISC was positively associated with pro-relationship behavior use, but this association was mediated by greater communal strength. This suggests that increased RISC is associated with greater relationship satisfaction because the manner in which individuals view their relationships (i.e., communally) explains the association between RISC and constructive relationship behavior

    More poor kids in more poor places: children increasingly live where poverty persists

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    More poor kids in more poor places: children increasingly live where poverty persist

    Mechanics of universal horizons

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    Modified gravity models such as Ho\v{r}ava-Lifshitz gravity or Einstein-{\ae}ther theory violate local Lorentz invariance and therefore destroy the notion of a universal light cone. Despite this, in the infrared limit both models above possess static, spherically symmetric solutions with "universal horizons" - hypersurfaces that are causal boundaries between an interior region and asymptotic spatial infinity. In other words, there still exist black hole solutions. We construct a Smarr formula (the relationship between the total energy of the spacetime and the area of the horizon) for such a horizon in Einstein-{\ae}ther theory. We further show that a slightly modified first law of black hole mechanics still holds with the relevant area now a cross-section of the universal horizon. We construct new analytic solutions for certain Einstein-{\ae}ther Lagrangians and illustrate how our results work in these exact cases. Our results suggest that holography may be extended to these theories despite the very different causal structure as long as the universal horizon remains the unique causal boundary when matter fields are added.Comment: Minor clarifications. References update
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