9,496 research outputs found

    New Hints from General Relativity

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    The search for a quantum theory of gravity has followed two parallel but different paths. One aims at arriving at the final theory starting from a priori assumptions as to its form and building it from the ground up. The other tries to infer as much as possible about the unknown theory from the existing ones and use our current knowledge to constrain the possibilities for the quantum theory of gravity. Probably the biggest success of the second path has been the results of black hole thermodynamics. The subject of this essay is a new, highly promising such result, the application of quasinormal modes in quantum gravity.Comment: This essay received an "honorable mention" in the 2003 Essay Competition of the Gravity Research Foundatio

    Geometric Modular Action and Spacetime Symmetry Groups

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    A condition of geometric modular action is proposed as a selection principle for physically interesting states on general space-times. This condition is naturally associated with transformation groups of partially ordered sets and provides these groups with projective representations. Under suitable additional conditions, these groups induce groups of point transformations on these space-times, which may be interpreted as symmetry groups. The consequences of this condition are studied in detail in application to two concrete space-times -- four-dimensional Minkowski and three-dimensional de Sitter spaces -- for which it is shown how this condition characterizes the states invariant under the respective isometry group. An intriguing new algebraic characterization of vacuum states is given. In addition, the logical relations between the condition proposed in this paper and the condition of modular covariance, widely used in the literature, are completely illuminated.Comment: 83 pages, AMS-TEX (format changed to US letter size

    Editor\u27s Note, Vol. 57, No. 3

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    Greetings from the Editors of Court Review! We are all heading into the last quarter of yet another year of pandemic, and our courts surely feel the brunt of it all. As judges confront the everyday problems of ordinary Americans, the ongoing stress and management challenges are taking its toll. We are always committed to providing valuable content and information to help ease the burden. Congratulations to you for all the hard work amidst an uncertain time. This issue presents the annual return of our U.S. Supreme Court review of notable civil cases from the 2020 Term ending last June 30. Thomas M. Fisher, Solicitor General of the State of Indiana, and four-time High Court contender, again adroitly outlines a challenging set of civil cases. We all benefit from this formidable round-up and discussion of our current legal landscape

    An examination of academic outcomes for students who attend a school-based afterschool program

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    While most research on the benefits of afterschool programs has shown positive behavioral outcomes, the results on academic outcomes have been mixed. This study focused on academic outcomes to further explore whether students who regularly attended a school-based afterschool program showed greater academic gains than students who did not attend. Previous research has shown mixed results in academic outcomes from afterschool programs depending on gender, program location and grade level; therefore, these variables were examined to evaluate where group differences may exist. Afterschool attendance was considered and narrowly defined to provide more understanding about dosage in afterschool outcomes research. Students in this study were in grades 3 through 8 during the 2008-2009 school year, and they attended two charter schools in Western Pennsylvania. The afterschool programs operated within the charter schools. This is a secondary data analysis, using data that were collected for a program evaluation of the afterschool programs. To measure academic gains, a difference score was calculated from students' pretest and posttest scores on the 4Sight reading and mathematics assessments. The design of this study was a quasi-experimental design comparing students who regularly attended the afterschool programs (50% or greater attendance) with a randomly selected comparison group from the same population of charter school students. An overall Analysis of Variance (ANOVA) on the difference scores showed that afterschool participants with regular attendance performed better than nonparticipants in mathematics but not in reading. Further ANOVAs on the mathematics difference scores found no differences in gain scores by gender. Elementary students showed greater mathematics gains than middle school students, and students who attended the afterschool program at School M showed greater mathematics gains than students at School H. The reading gain scores were also further analyzed with ANOVAs, and boys showed greater gains than girls, elementary students showed greater gains than middle school students, and students at School M showed greater gains than students at School H. No correlation was found between the number of days of afterschool attendance and reading or mathematics gain scores. Findings are related to future directions for afterschool research and implications for afterschool providers

    Editor\u27s Note, Vol. 58, No. 3

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    Greetings from the Editors of Court Review! Even though we are all thinking that the pandemic is past, our courts are still working on the aftereffects. Overdue jury trials, long awaited hearings, and the pent-up demand for attention among our litigants keeps our caseloads active and urgent. As judges confront the everyday problems of ordinary Americans, we are always committed to providing valuable content and information to help ease the burden. Congratulations to you for all the hard work amidst an uncertain time

    The university in a developing society

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    In I his article the universality and in particular also the particularity of the university are dealt with. The author points out the indissoluble link between the university and the community, and also stresses that the university may not remain at a distance or be cold about the society in which it finds itself. Developing communities in Africa have held unrealistic expectations about what education (and the universities) would be able to do within their societies. These expectations, however, did not materialize. The university in a developing community, therefore, today has a jar greater task than its peer in any other community: the former is not only within the community, but is part of it. For that reason this university should also take the lead with regard to the solution of present problems in the community; it has an educational objective, has to povide guidance and has to counsel the community in time regarding problems that will still be encountered
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