780 research outputs found

    An Analysis of Accelerated Christian Education and College Preparedness Based on ACT Scores

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    The current paper discusses Christian education in relation to college preparedness. The author focuses on Christian education and the use of Accelerated Christian Education, a prepackaged curriculum, specifically used in private fundamentalist Christian schools. Relevant research is reviewed regarding college preparedness and Christian education. The researcher obtained the ACT scores received by graduates of an ACE school over the past five years. These scores were analyzed using a t-test of comparative means (p\u3c.05) to determine if there were a significant differences in ACT scores between students at the Accelerated Christian School and the students of a public high school in the same area with a graduate college application rate of 75-83%. Scores were analyzed and a significant difference was found between the public school graduatesí scores and the ACE graduatesí scores in all areas of the ACT (English, Math, Reading, and Composite Score), except the area of Science Reasoning. Overall, the ACT scores of the ACE graduates were consistently lower than those of the public school students

    Data Acquisition, Triggering, and Filtering at the Auger Engineering Radio Array

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    The Auger Engineering Radio Array (AERA) is currently detecting cosmic rays of energies at and above 10^17 eV at the Pierre Auger Observatory, by triggering on the radio emission produced in the associated air showers. The radio-detection technique must cope with a significant background of man-made radio-frequency interference, but can provide information on shower development with a high duty cycle. We discuss our techniques to handle the challenges of self-triggered radio detection in a low-power autonomous array, including triggering and filtering algorithms, data acquisition design, and communication systems.Comment: Contribution to VLVnT 2011, to be published in NIM A, 4 pages, 6 figure

    Expansive actions on uniform spaces and surjunctive maps

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    We present a uniform version of a result of M. Gromov on the surjunctivity of maps commuting with expansive group actions and discuss several applications. We prove in particular that for any group Γ\Gamma and any field \K, the space of Γ\Gamma-marked groups GG such that the group algebra \K[G] is stably finite is compact.Comment: 21 page

    The universal Glivenko-Cantelli property

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    Let F be a separable uniformly bounded family of measurable functions on a standard measurable space, and let N_{[]}(F,\epsilon,\mu) be the smallest number of \epsilon-brackets in L^1(\mu) needed to cover F. The following are equivalent: 1. F is a universal Glivenko-Cantelli class. 2. N_{[]}(F,\epsilon,\mu)0 and every probability measure \mu. 3. F is totally bounded in L^1(\mu) for every probability measure \mu. 4. F does not contain a Boolean \sigma-independent sequence. It follows that universal Glivenko-Cantelli classes are uniformity classes for general sequences of almost surely convergent random measures.Comment: 26 page

    Cartan subalgebras in C*-algebras of Hausdorff etale groupoids

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    The reduced C∗C^*-algebra of the interior of the isotropy in any Hausdorff \'etale groupoid GG embeds as a C∗C^*-subalgebra MM of the reduced C∗C^*-algebra of GG. We prove that the set of pure states of MM with unique extension is dense, and deduce that any representation of the reduced C∗C^*-algebra of GG that is injective on MM is faithful. We prove that there is a conditional expectation from the reduced C∗C^*-algebra of GG onto MM if and only if the interior of the isotropy in GG is closed. Using this, we prove that when the interior of the isotropy is abelian and closed, MM is a Cartan subalgebra. We prove that for a large class of groupoids GG with abelian isotropy---including all Deaconu--Renault groupoids associated to discrete abelian groups---MM is a maximal abelian subalgebra. In the specific case of kk-graph groupoids, we deduce that MM is always maximal abelian, but show by example that it is not always Cartan.Comment: 14 pages. v2: Theorem 3.1 in v1 incorrect (thanks to A. Kumjain for pointing out the error); v2 shows there is a conditional expectation onto MM iff the interior of the isotropy is closed. v3: Material (including some theorem statements) rearranged and shortened. Lemma~3.5 of v2 removed. This version published in Integral Equations and Operator Theor

    Hidden fine tuning in the quark sector of little higgs models

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    In little higgs models a collective symmetry prevents the higgs from acquiring a quadratically divergent mass at one loop. By considering first the littlest higgs model we show that this requires a fine tuning: the couplings in the model introduced to give the top quark a mass do not naturally respect the collective symmetry. We show the problem is generic: it arises from the fact that the would be collective symmetry of any one top quark mass term is broken by gauge interactions.Comment: 15 pages, 1 figur

    Bounded and unitary elements in pro-C^*-algebras

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    A pro-C^*-algebra is a (projective) limit of C^*-algebras in the category of topological *-algebras. From the perspective of non-commutative geometry, pro-C^*-algebras can be seen as non-commutative k-spaces. An element of a pro-C^*-algebra is bounded if there is a uniform bound for the norm of its images under any continuous *-homomorphism into a C^*-algebra. The *-subalgebra consisting of the bounded elements turns out to be a C^*-algebra. In this paper, we investigate pro-C^*-algebras from a categorical point of view. We study the functor (-)_b that assigns to a pro-C^*-algebra the C^*-algebra of its bounded elements, which is the dual of the Stone-\v{C}ech-compactification. We show that (-)_b is a coreflector, and it preserves exact sequences. A generalization of the Gelfand-duality for commutative unital pro-C^*-algebras is also presented.Comment: v2 (accepted

    Pairing symmetry and long range pair potential in a weak coupling theory of superconductivity

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    We study the superconducting phase with two component order parameter scenario, such as, dx2−y2+eiθsαd_{x^2-y^2} + e^{i\theta}s_{\alpha}, where α=xy,x2+y2\alpha = xy, x^2+y^2. We show, that in absence of orthorhombocity, the usual dx2−y2d_{x^2-y^2} does not mix with usual sx2+y2s_{x^2+y^2} symmetry gap in an anisotropic band structure. But the sxys_{xy} symmetry does mix with the usual d-wave for θ=0\theta =0. The d-wave symmetry with higher harmonics present in it also mixes with higher order extended ss wave symmetry. The required pair potential to obtain higher anisotropic dx2−y2d_{x^2-y^2} and extended s-wave symmetries, is derived by considering longer ranged two-body attractive potential in the spirit of tight binding lattice. We demonstrate that the dominant pairing symmetry changes drastically from dd to ss like as the attractive pair potential is obtained from longer ranged interaction. More specifically, a typical length scale of interaction ξ\xi, which could be even/odd multiples of lattice spacing leads to predominant s/ds/d wave symmetry. The role of long range interaction on pairing symmetry has further been emphasized by studying the typical interplay in the temperature dependencies of these higher order dd and ss wave pairing symmetries.Comment: Revtex 8 pages, 7 figures embeded in the text, To appear in PR

    Bottom-Tau Unification in SUSY SU(5) GUT and Constraints from b to s gamma and Muon g-2

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    An analysis is made on bottom-tau Yukawa unification in supersymmetric (SUSY) SU(5) grand unified theory (GUT) in the framework of minimal supergravity, in which the parameter space is restricted by some experimental constraints including Br(b to s gamma) and muon g-2. The bottom-tau unification can be accommodated to the measured branching ratio Br(b to s gamma) if superparticle masses are relatively heavy and higgsino mass parameter \mu is negative. On the other hand, if we take the latest muon g-2 data to require positive SUSY contributions, then wrong-sign threshold corrections at SUSY scale upset the Yukawa unification with more than 20 percent discrepancy. It has to be compensated by superheavy threshold corrections around the GUT scale, which constrains models of flavor in SUSY GUT. A pattern of the superparticle masses preferred by the three requirements is also commented.Comment: 21pages, 6figure

    Time-averaging for weakly nonlinear CGL equations with arbitrary potentials

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    Consider weakly nonlinear complex Ginzburg--Landau (CGL) equation of the form: ut+i(−Δu+V(x)u)=ϵμΔu+ϵP(u),x∈Rd ,(∗) u_t+i(-\Delta u+V(x)u)=\epsilon\mu\Delta u+\epsilon \mathcal{P}( u),\quad x\in {R^d}\,, \quad(*) under the periodic boundary conditions, where μ⩾0\mu\geqslant0 and P\mathcal{P} is a smooth function. Let {ζ1(x),ζ2(x),… }\{\zeta_1(x),\zeta_2(x),\dots\} be the L2L_2-basis formed by eigenfunctions of the operator −Δ+V(x)-\Delta +V(x). For a complex function u(x)u(x), write it as u(x)=∑k⩾1vkζk(x)u(x)=\sum_{k\geqslant1}v_k\zeta_k(x) and set Ik(u)=12∣vk∣2I_k(u)=\frac{1}{2}|v_k|^2. Then for any solution u(t,x)u(t,x) of the linear equation (∗)ϵ=0(*)_{\epsilon=0} we have I(u(t,⋅))=constI(u(t,\cdot))=const. In this work it is proved that if equation (∗)(*) with a sufficiently smooth real potential V(x)V(x) is well posed on time-intervals t≲ϵ−1t\lesssim \epsilon^{-1}, then for any its solution uϵ(t,x)u^{\epsilon}(t,x), the limiting behavior of the curve I(uϵ(t,⋅))I(u^{\epsilon}(t,\cdot)) on time intervals of order ϵ−1\epsilon^{-1}, as ϵ→0\epsilon\to0, can be uniquely characterized by a solution of a certain well-posed effective equation: ut=ϵμ△u+ϵF(u), u_t=\epsilon\mu\triangle u+\epsilon F(u), where F(u)F(u) is a resonant averaging of the nonlinearity P(u)\mathcal{P}(u). We also prove a similar results for the stochastically perturbed equation, when a white in time and smooth in xx random force of order ϵ\sqrt\epsilon is added to the right-hand side of the equation. The approach of this work is rather general. In particular, it applies to equations in bounded domains in RdR^d under Dirichlet boundary conditions
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