5,513 research outputs found

    Tiwah upacara kematian pada Masyarakat Dayak Ngaju di Kalimantan Tengah

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    Dari berba,gai kebudayaan dan adat istiadat yang hidup di indonesia belum semua deskripsinya dapat dikumpulkan serta didokumentasikan baik dalam bentuk penerbitan buku maupun melalui media teknologi . yang lain seperti film, slide, dan sebagainya. Dengan demikian aneka ragam kebudayaan Indonesia kurang dikenal dan menyebar luas di kalangan masyarakat Indonesia sendiri maupun masyariikat asing. Untuk memperkaya informasi ·tentang khasanah. kebudayaan Indonesia, dalam kesempatan ini kami hadirkan di tengah · sidang pembaca yang budiman tulisan yang menggambarkan seluk beluk 'Upacara Kematian di Kalimantan Tengah". Perhatian utama dalam tulisan ini terpusat pada kekhususan upacara kematian yang diselenggarakan menurut adat istiadat dan kebudayaan Dayak yang ada di Kalimantan Tengah, dan khusΌsnya upacara kematian pada sukubangsa Dayak Ngaju yakni 'Upacara Tiwah'

    Poincare Recurrences and Topological Diversity

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    Finite entropy thermal systems undergo Poincare recurrences. In the context of field theory, this implies that at finite temperature, timelike two-point functions will be quasi-periodic. In this note we attempt to reproduce this behavior using the AdS/CFT correspondence by studying the correlator of a massive scalar field in the bulk. We evaluate the correlator by summing over all the SL(2,Z) images of the BTZ spacetime. We show that all the terms in this sum receive large corrections after at certain critical time, and that the result, even if convergent, is not quasi-periodic. We present several arguments indicating that the periodicity will be very difficult to recover without an exact re-summation, and discuss several toy models which illustrate this. Finally, we consider the consequences for the information paradox.Comment: 18 + 8 pages, 5 figures. v2: reference adde

    Asymptotic Level Spacing of the Laguerre Ensemble: A Coulomb Fluid Approach

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    We determine the asymptotic level spacing distribution for the Laguerre Ensemble in a single scaled interval, (0,s)(0,s), containing no levels, E_{\bt}(0,s), via Dyson's Coulomb Fluid approach. For the α=0\alpha=0 Unitary-Laguerre Ensemble, we recover the exact spacing distribution found by both Edelman and Forrester, while for α≠0\alpha\neq 0, the leading terms of E2(0,s)E_{2}(0,s), found by Tracy and Widom, are reproduced without the use of the Bessel kernel and the associated Painlev\'e transcendent. In the same approximation, the next leading term, due to a ``finite temperature'' perturbation (\bt\neq 2), is found.Comment: 10pp, LaTe

    Does Inflation Provide Natural Initial Conditions for the Universe?

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    If our universe underwent inflation, its entropy during the inflationary phase was substantially lower than it is today. Because a low-entropy state is less likely to be chosen randomly than a high-entropy one, inflation is unlikely to arise through randomly-chosen initial conditions. To resolve this puzzle, we examine the notion of a natural state for the universe, and argue that it is a nearly-empty spacetime. If empty space has a small vacuum energy, however, inflation can begin spontaneously in this background. This scenario explains why a universe like ours is likely to have begun via a period of inflation, and also provides an origin for the cosmological arrow of time.Comment: Submitted to Gravity Research Foundation Essay Competition; based on hep-th/041027

    The Probability of an Eigenvalue Number Fluctuation in an Interval of a Random Matrix Spectrum

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    We calculate the probability to find exactly nn eigenvalues in a spectral interval of a large random N×NN \times N matrix when this interval contains sâ‰ȘNs \ll N eigenvalues on average. The calculations exploit an analogy to the problem of finding a two-dimensional charge distribution on the interface of a semiconductor heterostructure under the influence of a split gate.Comment: 4 pages, postscrip

    Tachyons in de Sitter space and analytical continuation from dS/CFT to AdS/CFT

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    We discuss analytic continuation from d-dimensional Lorentzian de Sitter (dSd_d) to d-dimensional Lorentzian anti-de Sitter (AdSd_{d}) spacetime. We show that AdSd_{d}, with opposite signature of the metric, can be obtained as analytic continuation of a portion of dSd_d. This implies that the dynamics of (positive square-mass) scalar particles in AdSd_{d} can be obtained from the dynamics of tachyons in dSd_d. We discuss this correspondence both at the level of the solution of the field equations and of the Green functions. The AdS/CFT duality is obtained as analytic continuation of the dS/CFT duality.Comment: 17 pages, 1 figure, JHEP styl

    Periodic orbit theory and spectral rigidity in pseudointegrable systems

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    We calculate numerically the periodic orbits of pseudointegrable systems of low genus numbers gg that arise from rectangular systems with one or two salient corners. From the periodic orbits, we calculate the spectral rigidity Δ3(L)\Delta_3(L) using semiclassical quantum mechanics with LL reaching up to quite large values. We find that the diagonal approximation is applicable when averaging over a suitable energy interval. Comparing systems of various shapes we find that our results agree well with Δ3\Delta_3 calculated directly from the eigenvalues by spectral statistics. Therefore, additional terms as e.g. diffraction terms seem to be small in the case of the systems investigated in this work. By reducing the size of the corners, the spectral statistics of our pseudointegrable systems approaches the one of an integrable system, whereas very large differences between integrable and pseudointegrable systems occur, when the salient corners are large. Both types of behavior can be well understood by the properties of the periodic orbits in the system

    Kepler and the Kuiper Belt

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    The proposed field-of-view of the Kepler mission is at an ecliptic latitude of ~55 degrees, where the surface density of scattered Kuiper Belt Objects (KBOs) is a few percent that in the ecliptic plane. The rate of occultations of Kepler target stars by scattered KBOs with radii r>10km is ~10^-6 to 10^-4 per star per year, where the uncertainty reflects the current ignorance of the thickness of the scattered KBO disk and the faint-end slope of their magnitude distribution. These occultation events will last only ~0.1% of the planned t_exp=15 minute integration time, and thus will appear as single data points that deviate by tiny amounts. However, given the target photometric accuracy of Kepler, these deviations will nevertheless be highly significant, with typical signal-to-noise ratios of ~10. I estimate that 1-20 of the 10^5 main-sequence stars in Kepler's field-of-view will exhibit detectable occultations during its four-year mission. For unresolved events, the signal-to-noise of individual occultations scales as t_exp^{-1/2}, and the minimum detectable radius could be decreased by an order of magnitude to ~1 km by searching the individual 3-second readouts for occultations. I propose a number of methods by which occultation events may be differentiated from systematic effects. Kepler should measure or significantly constrain the frequency of highly-inclined, ~10 km-sized KBOs.Comment: 5 pages, 1 figure. No changes. Accepted to ApJ, to appear in the August 1, 2004 issue (v610

    Action research in physical education: focusing beyond myself through cooperative learning

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    This paper reports on the pedagogical changes that I experienced as a teacher engaged in an action research project in which I designed and implemented an indirect, developmentally appropriate and child‐centred approach to my teaching. There have been repeated calls to expunge – or at least rationalise – the use of traditional, teacher‐led practice in physical education. Yet despite the advocacy of many leading academics there is little evidence that such a change of approach is occurring. In my role as teacher‐as‐researcher I sought to implement a new pedagogical approach, in the form of cooperative learning, and bring about a positive change in the form of enhanced pupil learning. Data collection included a reflective journal, post‐teaching reflective analysis, pupil questionnaires, student interviews, document analysis, and non‐participant observations. The research team analysed the data using inductive analysis and constant comparison. Six themes emerged from the data: teaching and learning, reflections on cooperation, performance, time, teacher change, and social interaction. The paper argues that cooperative learning allowed me to place social and academic learning goals on an even footing, which in turn placed a focus on pupils’ understanding and improvement of skills in athletics alongside their interpersonal development
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