5,830 research outputs found
Multiplicity of Closed Reeb Orbits on Prequantization Bundles
We establish multiplicity results for geometrically distinct contractible
closed Reeb orbits of non-degenerate contact forms on a broad class of
prequantization bundles. The results hold under certain index requirements on
the contact form and are sharp for unit cotangent bundles of CROSS's. In
particular, we generalize and put in the symplectic-topological context a
theorem of Duan, Liu, Long, and Wang for the standard contact sphere. We also
prove similar results for non-hyperbolic contractible closed orbits and briefly
touch upon the multiplicity problem for degenerate forms. On the combinatorial
side of the question, we revisit and reprove the enhanced common jump theorem
of Duan, Long and Wang, and interpret it as an index recurrence result.Comment: 31 page
Comments on 4-point functions in the CFT/AdS correspondence
We study the four--point function of chiral primaries corresponding to the
dilaton--axion sector in supergravity in the /CFT correspondence. We
find relations between some of the supergravity graphs and compute their
leading singularities. We discuss the issue of logarithmic singularities and
their significance for the OPE structure of the CFT.Comment: Latex, 12 pages, Some typos correcte
Intersectionality, Race-Gender Subordination, and Education
In this chapter, we unpack intersectionality as an analytical framework. First, we cite Black Lives Matter as an impetus for discussing intersectionality’s current traction. Second, we review the genealogy of “intersectionality” beginning with Kimberlé Crenshaw’s formulation, which brought a Black Studies provocation into legal discourse in order to challenge existing antidiscrimination doctrine and single-axis theorizing. The third, and most central, task of the chapter is our account of intersectionality’s utility for social analysis. We examine some of the issues raised by the metaphor of the intersection and some of the debates surrounding the concept, such as the tension between fragmenting and universalizing perspectives mediated by the notion of “strategic essentialism.” Fourth, we review how education researchers have explained race and gender subordination in education since Ladson-Billings and Tate’s Teachers College Record article. We conclude with some remarks concerning future research on intersectionality
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