33,745 research outputs found

    Effect of Dilution on First Order Transitions: The Three Dimensional Three States Potts Model

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    We have studied numerically the effect of quenched site dilution on a first order phase transition in three dimensions. We have simulated the site diluted three states Potts model studying in detail the second order region of its phase diagram. We have found that the ν\nu exponent is compatible with the one of the three dimensional diluted Ising model whereas the η\eta exponent is definitely different.Comment: RevTex. 6 pages and 6 postscript figure

    Are the hosts of VLBI selected radio-AGN different to those of radio-loud AGN?

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    Recent studies have found that radio-AGN selected by radio-loudness show little difference in terms of their host galaxy properties when compared to non-AGN galaxies of similar stellar mass and redshift. Using new 1.4~GHz VLBI observations of the COSMOS field we find that approximately 49±8\pm8\% of high-mass (M >> 1010.5^{10.5} M⊙_{\odot}), high luminosity (L1.4_{1.4} >> 1024^{24} W~Hz−1^{-1}) radio-AGN possess a VLBI detected counterpart. These objects show no discernible bias towards specific stellar masses, redshifts or host properties other than what is shown by the radio-AGN population in general. Radio-AGN that are detected in VLBI observations are not special, but form a representative sample of the radio-loud AGN population.Comment: 6 pages, 4 figures, lette

    The out-equilibrium 2D Ising spin glass: almost, but not quite, a free-field theory

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    We consider the spatial correlation function of the two-dimensional Ising spin glass under out-equilibrium conditions. We pay special attention to the scaling limit reached upon approaching zero temperature. The field-theory of a non-interacting field makes a surprisingly good job at describing the spatial shape of the correlation function of the out-equilibrium Edwards-Anderson Ising model in two dimensions.Comment: 20 pages + 5 Figure

    Developing collaborative partnerships with culturally and linguistically diverse families during the IEP process

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    Family participation in the special education process has been federally mandated for 40 years, and educators recognize that effective collaboration with their students’ families leads to improved academic and social outcomes for students. However, while some family-school relationships are positive and collaborative, many are not, particularly for culturally and linguistically diverse (CLD) families. This article provides practice guidelines based in research for teachers who seek to improve their practices when working with CLD families who have children served by special education

    Landau-gauge condensates from the quark propagator on the lattice

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    We compute the dimension-2 condensate, , and the dimension-4 mixed condensate, , from the recent quenched lattice results for the quark propagator in the Landau gauge. We fit the lattice data to the Operator Product Expansion in the "fiducial" region 1.2 GeV < Q < 3 GeV. Our result for the dynamical gluon mass at the scale of 10 GeV^2 is m_A=600-650 MeV, in agreement with independent determinations. For the mixed Landau gauge condensate of dimension-4 we get alpha_s = (-0.11 +/- 0.03) GeV^4. This value is an order of magnitude larger than the gluon condensate.Comment: 4 pages, 3 figures, references adde

    Darboux points and integrability of homogeneous Hamiltonian systems with three and more degrees of freedom

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    We consider natural complex Hamiltonian systems with nn degrees of freedom given by a Hamiltonian function which is a sum of the standard kinetic energy and a homogeneous polynomial potential VV of degree k>2k>2. The well known Morales-Ramis theorem gives the strongest known necessary conditions for the Liouville integrability of such systems. It states that for each kk there exists an explicitly known infinite set \scM_k\subset\Q such that if the system is integrable, then all eigenvalues of the Hessian matrix V''(\vd) calculated at a non-zero \vd\in\C^n satisfying V'(\vd)=\vd, belong to \scM_k. The aim of this paper is, among others, to sharpen this result. Under certain genericity assumption concerning VV we prove the following fact. For each kk and nn there exists a finite set \scI_{n,k}\subset\scM_k such that if the system is integrable, then all eigenvalues of the Hessian matrix V''(\vd) belong to \scI_{n,k}. We give an algorithm which allows to find sets \scI_{n,k}. We applied this results for the case n=k=3n=k=3 and we found all integrable potentials satisfying the genericity assumption. Among them several are new and they are integrable in a highly non-trivial way. We found three potentials for which the additional first integrals are of degree 4 and 6 with respect to the momenta.Comment: 54 pages, 1 figur
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