6,483 research outputs found

    Tensor Bounds on the Hidden Universe

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    During single clock inflation, hidden fields (i.e. fields coupled to the inflaton only gravitationally) in their adiabatic vacua can ordinarily only affect observables through virtual effects. After renormalizing background quantities (fixed by observations at some pivot scale), all that remains are logarithmic runnings in correlation functions that are both Planck and slow roll suppressed. In this paper we show how a large number of hidden fields can partially compensate this suppression and generate a potentially observable running in the tensor two point function, consistently inferable courtesy of a large NN resummation. We detour to address certain subtleties regarding loop corrections during inflation, extending the analysis of [1]. Our main result is that one can extract bounds on the hidden field content of the universe from bounds on violations of the consistency relation between the tensor spectral index and the tensor to scalar ratio, were primordial tensors ever detected. Such bounds are more competitive than the naive bound inferred from requiring inflation to occur below the strong coupling scale of gravity if deviations from the consistency relation can be bounded to within the sub-percent level. We discuss how one can meaningfully constrain the parameter space of various phenomenological scenarios and constructions that address naturalness with a large number of species (such as `N-naturalness') with CMB observations up to cosmic variance limits, and possibly future 21cm and gravitational wave observations.Comment: 14 pages, 4 figures, 3 appendices. Version accepted to JHEP; references added, updated bounds on rr incorporate

    Tradable Permits Under Threat to Manage Nonpoint Source Pollution

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    In this article we treat the problem of nonpoint source pollution as a problem of moral hazard in group. To solve this kind of problem we consider a group performance based tax coupled to tradable permits market. The tax is activated if the group fails to meet the ambient standard. So the role of the tax is to provide an incitation to ensure that the agents provide the abatement level necessary to achieve the standard. The role of the tradable permits market is to distribute effectively this abatement level through the price of the permits which rises with the exchange of the permits.nonpoint source pollution, ambient tax, tradable permits market, Environmental Economics and Policy,

    The geometry of modified Riemannian extensions

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    We show that every paracomplex space form is locally isometric to a modified Riemannian extension and give necessary and sufficient conditions so that a modified Riemannian extension is Einstein. We exhibit Riemannian extension Osserman manifolds of signature (3,3) whose Jacobi operators have non-trivial Jordan normal form and which are not nilpotent. We present new four dimensional results in Osserman geometry

    Pelaksanaan Perjanjian Ekspedisi melalui Angkutan Udara (Sudi pada PT Anugerah Semesta Persada)

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    Shipping agreement with PT Anugerah Semesta Persada was made verbally. PT Anugerah Semesta Persada used verbal agreement because not only it acted on behalf of the consigner, but also as the expediter that directly connected with the shipping agency. It was the accountability of PT Anugerah Semesta Persada that the customer incurred loss in the shipping agreement because of the very limited availability of air freight transportation. PT Anugerah Semesta Persada was accountable for the compensation due to its fault to pay the highest price of the goods. It had not paid the compensation for the transport cost that had been expended by the consigner .The legal protection for the consumers that incur loss in the goods shipping agreement with PT Anugerah Semesta Persada is regulated in the legal provisions regarding freightage either preventively or repressively
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