97 research outputs found

    Gauge-Invariant Coordinates on Gauge-Theory Orbit Space

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    A gauge-invariant field is found which describes physical configurations, i.e. gauge orbits, of non-Abelian gauge theories. This is accomplished with non-Abelian generalizations of the Poincare'-Hodge formula for one-forms. In a particular sense, the new field is dual to the gauge field. Using this field as a coordinate, the metric and intrinsic curvature are discussed for Yang-Mills orbit space for the (2+1)- and (3+1)-dimensional cases. The sectional, Ricci and scalar curvatures are all formally non-negative. An expression for the new field in terms of the Yang-Mills connection is found in 2+1 dimensions. The measure on Schroedinger wave functionals is found in both 2+1 and 3+1 dimensions; in the former case, it resembles Karabali, Kim and Nair's measure. We briefly discuss the form of the Hamiltonian in terms of the dual field and comment on how this is relevant to the mass gap for both the (2+1)- and (3+1)-dimensional cases.Comment: Typos corrected, more about the non-Abelian decomposition and inner products, more discussion of the mass gap in 3+1 dimensions. Now 23 page

    Scalar Field Dark Matter

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    This work is a review of the last results of research on the Scalar Field Dark Matter model of the Universe at cosmological and at galactic level. We present the complete solution to the scalar field cosmological scenario in which the dark matter is modeled by a scalar field Ί\Phi with the scalar potential V(Ί)=V0(cosh(λÎș0Ί)−1)V(\Phi)=V_{0}(cosh {(\lambda \sqrt{\kappa_{0}}\Phi)}-1) and the dark energy is modeled by a scalar field Κ\Psi, endowed with the scalar potential V~(Κ)=V0~(sinh⁥(αÎș0Κ))ÎČ\tilde{V}(\Psi)= \tilde{V_{0}}(\sinh{(\alpha \sqrt{\kappa_{0}}\Psi)})^{\beta}, which together compose the 95% of the total matter energy in the Universe. The model presents successfully deals with the up to date cosmological observations, and is a good candidate to treat the dark matter problem at the galactic level.Comment: 11 pagez, 5 figures, REVTeX. To appear in proceedings of the ``Mexican Meeting on Exact Solutions and Scalar Fields in Gravity '', in honour of Heinz Dehnen's 65th Birthday and Dietrich Kramer's 60th Birthday. Mexico D.F., Mexico, in press. More info at http://www.fis.cinvestav.mx/~siddh/PHI

    Successful Strategies for Promoting Self-Advocacy Among Students with LD: The LEAD Group

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    Students with learning disabilities (LD) often need to be taught self-determination skills to be better prepared for life after high school. This article describes the methods used by one school district to promote self-advocacy and self-awareness skills for students with LD. Through multicomponent group activities, students learned about their strengths and disabilities and how to advocate for their educational needs and rights. Advocacy skills were also applied to leadership roles, mentoring, and community education activities. Important features that contributed to the success of the program are described.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Supermassive Binaries and Extragalactic Jets

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    Some quasars show Doppler shifted broad emission line peaks. I give new statistics of the occurrence of these peaks and show that, while the most spectacular cases are in quasars with strong radio jets inclined to the line of sight, they are also almost as common in radio-quiet quasars. Theories of the origin of the peaks are reviewed and it is argued that the displaced peaks are most likely produced by the supermassive binary model. The separations of the peaks in the 3C 390.3-type objects are consistent with orientation-dependent "unified models" of quasar activity. If the supermassive binary model is correct, all members of "the jet set" (astrophysical objects showing jets) could be binaries.Comment: 31 pages, PostScript, missing figure is in ApJ 464, L105 (see http://www.aas.org/ApJ/v464n2/5736/5736.html

    X-Ray and Radio Observations of Bright GeV Sources

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    We present X-ray and radio studies of sources which are brightabove 1 GeV (F_{>1GeV} > 4e-8 ph/cm^2/s. Only 11 out of ~30 of these gamma-ray sources have been identified with lower energy counterparts: 5 blazars and 6 pulsars. Three of these pulsars are surrounded by radio pulsar wind nebulae (PWN), two of which are also seen as bright, extended X-ray synchrotron nebulae. The ASCA X-ray telescope has observed 28 of the bright GeV sources, revealing an excess of F_{2-10keV} > 10e-12 ergs/cm^2/s sources within the {\it EGRET} error contours of the unidentified sources. Although several supernova remnants are positionally coincident with these sources, we find no X-ray evidence of high energy particle production in SNR shell shocks consistent with the GeV positions. We also present initial results from follow on radio imaging studies of several fields containing unidentified sources. We have discovered new X-ray/radio nebulae in three of these fields which are strong candidates for PWN. These sources, along with a similar nebula in CTA 1 and the PWN around PSR B1853+01 in W44, are all positionally coincident with variable EGRET sources. This suggests a class of variable gamma-ray sources associated with synchrotron emitting regions powered by the winds of young pulsars.Comment: 18 pages, 26 figures, To appear in the proceedings of the workshop: "The Nature of the Unidentified Galactic Gamma-Ray Sources" held at INAOE, Mexico, October 2000, (A.Carraminana, O. Reiner and D. Thompson,

    Overstory influences on light attenuation patterns and understory plant community diversity and composition in southern boreal forests of Quebec

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    We have characterized overstory light transmission, understory light levels, and plant communities in mixedwood boreal forests of northwestern Quebec with the objective of understanding how overstory light transmission interacts with composition and time since disturbance to influence the diversity and composition of understory vegetation, and, in turn, the further attenuation of light to the forest floor by the understory. Overstory light transmission differed among three forest types (aspen, mixed deciduous-conifer, and old cedar-dominated), with old forests having higher proportions of high light levels than aspen and mixed forests, which were characterized by intermediate light levels. The composition of the understory plant communities in old forests showed the weakest correlation to overstory light transmission, although those forests had the largest range of light transmission. The strongest correlation between characteristics of overstory light transmission and understory communities was found in aspen forests. Species diversity indices were consistently higher in aspen forests but showed weak relationships with overstory light transmission. Light attenuation by the understory vegetation and total height of the understory vegetation were strongly and positively related to overstory light transmission but not forest type. Therefore, light transmission through the overstory influenced the structure and function of understory plants more than their diversity and composition. This is likely due to the strong effect of the upper understory layers, which tend to homogenize light levels at the forest floor regardless of forest type. The understory plant community acts as a filter, thereby reducing light levels at the forest floor to uniformly low levels

    Libertarian paternalism: Policy and everyday translations of the rational and the affective

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    Following the financial collapse in 2008 many commentators went onto pronounce the end of neoliberalism as a credible system for managing welfare state capitalism. The narrow economic belief in individuals as rational utility maximizers (the linchpin of neoliberal governance) was proved to be uncomfortably inaccurate. In light of these claims, British governments and think tanks have published various research and pol-icy documents promoting the use of soft forms of state power to ‘nudge’ citizens into behaving responsibly and rationally. Through an analysis of key policy documents and academic texts, I examine the repertoires and formulations informing this emerging governmental rationality (‘libertarian paternalism’) and draw together these perspectives to explore their effects in terms of framing policy understandings of the rational and the emotional. I conclude the article by utilizing a discursive psychology approach with the aim to problematize existing policy (mis)understandings of emotion as automated and unreflexive

    Experimental progress in positronium laser physics

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