53,226 research outputs found

    Local well-posedness of the generalized Cucker-Smale model

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    In this paper, we study the local well-posedness of two types of generalized Cucker-Smale (in short C-S) flocking models. We consider two different communication weights, singular and regular ones, with nonlinear coupling velocities vvβ2v|v|^{\beta-2} for β>3d2\beta > \frac{3-d}{2}. For the singular communication weight, we choose ψ1(x)=1/xα\psi^1(x) = 1/|x|^{\alpha} with α(0,d1)\alpha \in (0,d-1) and β2\beta \geq 2 in dimension d>1d > 1. For the regular case, we select ψ2(x)0\psi^2(x) \geq 0 belonging to (L_{loc}^\infty \cap \mbox{Lip}_{loc})(\mathbb{R}^d) and β(3d2,2)\beta \in (\frac{3-d}{2},2). We also remark the various dynamics of C-S particle system for these communication weights when β(0,3)\beta \in (0,3)

    Conservative accounting and linear information valuation models

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    Prior research using the residual income valuation model and linear information models has generally found that estimates of firm value are negatively biased. We argue that this could result from the way in which accounting conservatism effects are reflected in such models. We build on the conservative accounting model of Feltham and Ohlson (1995) and the Dechow, Hutton and Sloan (1999) (DHS) methodology to propose a valuation model that includes a conservatism-correction term, based on the properties of past realizations of residual income and other information. Other information is measured using analyst-forecast-based predictions of residual income. We use data comparable to the DHS sample to compare the bias and inaccuracy of value estimates from our model and from models similar to those used by DHS and Myers (1999). Valuation biases are substantially less negative for our model, but valuation inaccuracy is not markedly reduced

    Race, Culture & Abuse of Persons with Disabilities

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    This chapter will explore how race and culture influence the lives of persons with disabilities who are experiencing abuse. The discussion will be framed by an intersectional lens and will be informed by cultural humility and critical race theory. Practitioners need to remain open to the idea that they cannot and will not know all there is to know about any given culture, and they should be open to hearing about their clients’ understanding and experiences of culture. Rather than knowing certain pieces of “knowledge” about a cultural group, it is more important to understand what pieces of culture the clients embrace or reject. This chapter will conclude with a composite client case example of a female, middle-aged, Korean immigrant with Multiple Sclerosis, who is very active in her Christian church, and who is being abused by her husband. Discussion of this case will highlight the intersectional context of the client’s experience and how they may influence her decision to seek help (and from whom) as well as her experience of receiving help. The case discussion also highlights the practitioner’s values and behaviors that are consistent with cultural humility and critical race theory

    Relation between Kitaev magnetism and structure in α\alpha-RuCl3_3

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    Raman scattering has been employed to investigate lattice and magnetic excitations of the honeycomb Kitaev material α\alpha-RuCl3_3 and its Heisenberg counterpart CrCl3_3. Our phonon Raman spectra give evidence for a first-order structural transition from a monoclinic to a rhombohedral structure for both compounds. Significantly, only α\alpha-RuCl3_3 features a large thermal hysteresis, consistent with the formation of a wide phase of coexistence. In the related temperature interval of 7017070-170 K, we observe a hysteretic behavior of magnetic excitations as well. The stronger magnetic response in the rhombohedral compared to the monoclinic phase evidences a coupling between the crystallographic structure and low-energy magnetic response. Our results demonstrate that the Kitaev magnetism concomitant with fractionalized excitations is susceptible to small variations of bonding geometry.Comment: 9 pages, 8 figures, To appear in PR

    Determining SUSY Parameters in Chargino Pair-Production in e+ee^+e^- Collisions

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    In most supersymmetric theories, charginos χ~1,2±\tilde{\chi}^\pm_{1,2}, mixtures of charged color-neutral gauginos and higgsinos, belong to the class of the lightest supersymmetric particles. They are easy to observe at e+ee^+e^- colliders. By measuring the total cross sections and the left-right asymmetries with polarized electron beams in e+eχ~iχ~j+[i,j=1,2]e^+e^-\to\tilde{\chi}_i^-\tilde{\chi}_j^+ [i,j=1,2], the chargino masses and the gaugino-higgsino mixing angles can be determined. From these observables the fundamental SUSY parameters can be derived: the SU(2) gaugino mass M2M_2, the modulus μ|\mu| and cosΦμ\cos \Phi_\mu of the higgsino mass parameter, and tanβ=v2/v1\tan\beta = v_2/v_1, the ratio of the vacuum expectation values of the two neutral Higgs doublet fields. The solutions are unique; the CP-violating phase Φμ\Phi_\mu can be determined uniquely by analyzing effects due to the normal polarization of the charginos.Comment: 20 pages, 4 figures, uses axodraw.st

    Identifying the Higgs Spin and Parity in Decays to Z Pairs

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    Higgs decays to Z boson pairs may be exploited to determine spin and parity of the Higgs boson, a method complementary to spin-parity measurements in Higgs-strahlung. For a Higgs mass above the on-shell ZZ decay threshold, a model-independent analysis can be performed, but only by making use of additional angular correlation effects in gluon-gluon fusion at the LHC and gamma-gamma fusion at linear colliders. In the intermediate mass range, in which the Higgs boson decays into pairs of real and virtual Z bosons, threshold effects and angular correlations, parallel to Higgs-strahlung, may be adopted to determine spin and parity, though high event rates will be required for the analysis in practice.Comment: 14 pages, 2 postscript figure
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