3,462 research outputs found

    'Don't Run Up the Stairs!': Why Removing the Paramount Decrees Would Be Bad for Hollywood

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    TRADE AND POLICY IMPLICATIONS OF THE WHEAT DISEASE KARNAL BUNT

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    Agricultural and Food Policy, International Relations/Trade,

    SETTING INTERNATIONAL STANDARDS FOR FOOD AND AGRICULTURAL TRADE

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    International Relations/Trade,

    Impact of Numerical Relativity information on effective-one-body waveform models

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    We present a comprehensive comparison of the spin-aligned effective-one-body (EOB) waveform model of Nagar et al. [Phys. Rev. D93, 044046 (2016)], informed using 40 numerical-relativity (NR) datasets, against a set of 149, =m=2\ell=m=2, NR waveforms freely available through the Simulation Extreme Spacetime (SXS) catalog. We find that, without further calibration, these EOBNR waveforms have unfaithfulness (at design Advanced-LIGO sensitivity and evaluated with total mass MM varying as 10MM200M10M_\odot\leq M \leq 200M_\odot) always below 1%1\% against all NR waveforms except for three outliers, that still never exceed the 3%3\% level; with a minimal retuning of the (effective) next-to-next-to-next-to-leading-order spin-orbit coupling parameter for the non-equal-mass and non-equal-spin sector, that only needs three more NR waveforms, one is left with another two (though different) outliers, with maximal unfaithfulness of up to only 2%2\% for a total mass of 200M200M_\odot. We show this is the effect of slight inaccuracies in the phenomenological description of the postmerger waveform of Del Pozzo and Nagar [arXiv:1606.03952] that was constructed by interpolating over only 40NR simulations. We argue that this is easily fixed by using either an alternative ringdown description (e.g., the superposition of quasi-normal-modes) or an improved version of the phenomenological representation. By analyzing a NR waveform with mass ratio 88 and dimensionless spins +0.85+0.85 obtained with the BAM code, we conclude that the model would benefit from NR simulations specifically targeted at improving the postmerger-ringdown phenomenological fits for mass ratios 8\gtrsim 8 and spins 0.8\gtrsim 0.8.Comment: 24 pages, 20 figures, submitted to Phys. Rev.

    A Multipolar Effective One Body Model for Non-Spinning Black Hole Binaries

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    We introduce \TEOBiResumSM{}, a nonspinning inspiral-merger-ringdown waveform model built within the effective one body (EOB) framework that includes gravitational waveform modes beyond the dominant quadrupole (,m)=(2,2)(\ell,|m|) = (2,2). The model incorporates: (i) an improved Pad\'e resummation of the factorized waveform amplitudes ρmorb\rho_{\ell m}^{\rm orb} entering the EOB-resummed waveform where the 3PN, mass-ratio dependent, terms are hybridized with test-mass limit terms up to 6PN relative order for most of the multipoles up to =6\ell=6 included; (ii) an improved determination of the effective 5PN function a6c(ν)a_6^c(\nu) entering the EOB interaction potential done using the most recent, error-controlled, nonspinning numerical relativity (NR) waveforms from the Simulating eXtreme Spacetimes (SXS) collaboration; and (iii) a NR-informed phenomenological description of the multipolar ringdown. Such representation stems from 19 NR waveforms with mass ratios up to m1/m2=18m_1/m_2=18 as well as test-mass waveform data, although it does not incorporate mode-mixing effects. The NR-completed higher modes through merger and ringdown considered here are: (,m)={(2,1),(3,3),(3,2),(3,1),(4,4),(4,3),(4,2),(4,1),(5,5)}(\ell,|m|) = \lbrace (2,1), (3,3), (3,2),(3,1),(4,4), (4,3),(4,2), (4,1),(5,5)\rbrace. For simplicity, the other subdominant modes, up to =8\ell=8, are approximated by the corresponding, purely analytical, factorized and resummed EOB waveform. To attempt an estimate of (some of) the underlying analytic uncertainties of the model, we also contrast the effect of the 6PN-hybrid Pad\'e-resummed ρm\rho_{\ell m}'s with the standard 3+23^{+2}PN, Taylor-expanded, ones used in previous EOB works. The maximum unfaithfulness Fˉ\bar{F} against the SXS waveforms including all NR-completed modes up to =m=5\ell=m=5 is always 2%\lesssim 2\% for binaries with total mass MM as 50MM200M50 M_{\odot} \leq M \lesssim 200 M_{\odot}.Comment: 24 pages, 18 figures. Improved figures and presentation. Submitted to Phys. Rev.

    Box spline prewavelets of small support

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    The purpose of this paper is the construction of bi- and trivariate prewavelets from box-spline spaces, \ie\ piecewise polynomials of fixed degree on a uniform mesh. They have especially small support and form Riesz bases of the wavelet spaces, so they are stable. In particular, the supports achieved are smaller than those of the prewavelets due to Riemenschneider and Shen in a recent, similar constructio

    Deformations of Rational Singularities and Their Resolutions

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    Paper by Oswald Riemenschneide

    Remembering Syd

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    Reminiscenc

    Why Not a China Pattern

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    Her luncheon was a great success. How could it be otherwise? Her table appointments were faultless and the service perfect in every respect

    Considering Older Adults in Mainstream Technology Development

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