4,707 research outputs found

    Transformative Dynamics: Reframing the Role of Reparations in Transforming Social Order

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    According to Kathryn Sikkink, a revolution of human rights advocacy in tandem with heightened levels of accountability for human rights abuses has led to a “justice cascade,” where it is now expected that human rights violators will be held criminally accountable for transgressions. This normative shift of prosecuting individual perpetrators for human rights violations has also affected the larger picture of justice: human rights violations do not live in a silo and often occur against a backdrop of much-needed institutional reform. This Article considers the relationship between transitional justice, development programs, and social services, specifically using reparations as an example of a transitional justice mechanism. Although reparations and development programs may be connected, this Article argues that they must be kept separate for two reasons. First, combining the two overlooks the main purpose of reparations. Second, the combination muddles the appropriate level of expectation placed on each distinct effort and may place too high an expectation on reparations as the sole mechanism to transform social order. Therefore, establishing a clear limitation of what reparations can achieve properly situates individual transitional justice mechanisms as markers to establish what this Article calls “transformative dynamics.” Accordingly, a post-conflict environment may be more conducive to achieving a transformational agenda through the layering of these incremental transformative dynamics. Implementing a transitional justice mechanism, like a reparations program, may be one such incremental—though significant —marker, but it will not singly create the transformation ultimately sought. This framing of transformative dynamics attempts to mitigate the placement of unrealistic expectations on transitional justice mechanisms in the larger goal of transforming social order. This Article continues in five subsequent parts. Part II highlights applicable theory, beginning with a brief discussion of transitional justice and arguing instead for a transformative dynamics framework. This Part uses Robert Cox’s binary theoretical approaches to world order as an illustration. Part III introduces reparations as one transitional justice mechanism and explains how the purpose of reparations—specifically reparations under Roy Brooks’s Atonement Model—fundamentally limits what it can achieve, noting that reparations cannot and should not be expected to fill gaps in development programs or social services. Part IV addresses how reparations, development programs, and social services may be wrongly viewed as synonymous but can be complementary. Part V spotlights the importance of maintaining realistic expectations of transitional justice mechanisms in a transformative dynamics framework to properly measure success. Part VI concludes this Article

    Travelling-waves consistent with turbulence-driven secondary flow in a square duct

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    We present numerically determined travelling-wave solutions for pressure-driven flow through a straight duct with a square cross-section. This family of solutions represents typical coherent structures (a staggered array of counter-rotating streamwise vortices and an associated low-speed streak) on each wall. Their streamwise average flow in the cross-sectional plane corresponds to an eight vortex pattern much alike the secondary flow found in the turbulent regime

    High temperature expansion in supersymmetric matrix quantum mechanics

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    We formulate the high temperature expansion in supersymmetric matrix quantum mechanics with 4, 8 and 16 supercharges. The models can be obtained by dimensionally reducing N=1 U(N) super Yang-Mills theory in D=4,6,10 to 1 dimension, respectively. While the non-zero frequency modes become weakly coupled at high temperature, the zero modes remain strongly coupled. We find, however, that the integration over the zero modes that remains after integrating out all the non-zero modes perturbatively, reduces to the evaluation of connected Green's functions in the bosonic IKKT model. We perform Monte Carlo simulation to compute these Green's functions, which are then used to obtain the coefficients of the high temperature expansion for various quantities up to the next-leading order. Our results nicely reproduce the asymptotic behaviors of the recent simulation results at finite temperature. In particular, the fermionic matrices, which decouple at the leading order, give rise to substantial effects at the next-leading order, reflecting finite temperature behaviors qualitatively different from the corresponding models without fermions.Comment: 17 pages, 13 figures, (v2) some typos correcte

    Exact fuzzy sphere thermodynamics in matrix quantum mechanics

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    We study thermodynamical properties of a fuzzy sphere in matrix quantum mechanics of the BFSS type including the Chern-Simons term. Various quantities are calculated to all orders in perturbation theory exploiting the one-loop saturation of the effective action in the large-N limit. The fuzzy sphere becomes unstable at sufficiently strong coupling, and the critical point is obtained explicitly as a function of the temperature. The whole phase diagram is investigated by Monte Carlo simulation. Above the critical point, we obtain perfect agreement with the all order results. In the region below the critical point, which is not accessible by perturbation theory, we observe the Hagedorn transition. In the high temperature limit our model is equivalent to a totally reduced model, and the relationship to previously known results is clarified.Comment: 22 pages, 14 figures, (v2) some typos correcte

    Stabilized Kuramoto-Sivashinsky system

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    A model consisting of a mixed Kuramoto - Sivashinsky - KdV equation, linearly coupled to an extra linear dissipative equation, is proposed. The model applies to the description of surface waves on multilayered liquid films. The extra equation makes its possible to stabilize the zero solution in the model, opening way to the existence of stable solitary pulses (SPs). Treating the dissipation and instability-generating gain in the model as small perturbations, we demonstrate that balance between them selects two steady-state solitons from their continuous family existing in the absence of the dissipation and gain. The may be stable, provided that the zero solution is stable. The prediction is completely confirmed by direct simulations. If the integration domain is not very large, some pulses are stable even when the zero background is unstable. Stable bound states of two and three pulses are found too. The work was supported, in a part, by a joint grant from the Israeli Minsitry of Science and Technology and Japan Society for Promotion of Science.Comment: A text file in the latex format and 20 eps files with figures. Physical Review E, in pres

    Smearing Effect in Plane-Wave Matrix Model

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    Motivated by the usual D2-D0 system, we consider a configuration composed of flat membrane and fuzzy sphere membrane in plane-wave matrix model, and investigate the interaction between them. The configuration is shown to lead to a non-trivial interaction potential, which indicates that the fuzzy sphere membrane really behaves like a graviton, giant graviton. Interestingly, the interaction is of r^{-3} type rather than r^{-5} type. We interpret it as the interaction incorporating the smearing effect due to the fact that the considered supersymmetric flat membrane should span and spin in four dimensional subspace of plane-wave geometry.Comment: 26 pages; added referenc

    Exact Computation of Influence Spread by Binary Decision Diagrams

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    Evaluating influence spread in social networks is a fundamental procedure to estimate the word-of-mouth effect in viral marketing. There are enormous studies about this topic; however, under the standard stochastic cascade models, the exact computation of influence spread is known to be #P-hard. Thus, the existing studies have used Monte-Carlo simulation-based approximations to avoid exact computation. We propose the first algorithm to compute influence spread exactly under the independent cascade model. The algorithm first constructs binary decision diagrams (BDDs) for all possible realizations of influence spread, then computes influence spread by dynamic programming on the constructed BDDs. To construct the BDDs efficiently, we designed a new frontier-based search-type procedure. The constructed BDDs can also be used to solve other influence-spread related problems, such as random sampling without rejection, conditional influence spread evaluation, dynamic probability update, and gradient computation for probability optimization problems. We conducted computational experiments to evaluate the proposed algorithm. The algorithm successfully computed influence spread on real-world networks with a hundred edges in a reasonable time, which is quite impossible by the naive algorithm. We also conducted an experiment to evaluate the accuracy of the Monte-Carlo simulation-based approximation by comparing exact influence spread obtained by the proposed algorithm.Comment: WWW'1

    SuzakuSuzaku X-ray study of the double radio relic galaxy cluster CIZA J2242.8+5301

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    Content: We present the results from SuzakuSuzaku observations of the merging cluster of galaxies CIZA J2242.8+5301 at zz=0.192. Aims. To study the physics of gas heating and particle acceleration in cluster mergers, we investigated the X-ray emission from CIZA J2242.8+5301, which hosts two giant radio relics in the northern/southern part of the cluster. Methods. We analyzed data from three-pointed Suzaku observations of CIZA J2242.8+5301 to derive the temperature distribution in four different directions. Results: The Intra-Cluster Medium (ICM) temperature shows a remarkable drop from 8.50.6+0.8_{-0.6}^{+0.8} keV to 2.70.4+0.7_{-0.4}^{+0.7} keV across the northern radio relic. The temperature drop is consistent with a Mach number Mn=2.70.4+0.7{\cal M}_n=2.7^{+0.7}_{-0.4} and a shock velocity vshock:n=2300400+700kms1v_{shock:n}=2300_{-400}^{+700}\rm\,km\,s^{-1}. We also confirm the temperature drop across the southern radio relic. However, the ICM temperature beyond this relic is much higher than beyond the northern one, which gives a Mach number Ms=1.70.3+0.4{\cal M}_s=1.7^{+0.4}_{-0.3} and shock velocity vshock:s=2040410+550kms1v_{shock:s}=2040_{-410}^{+550}\rm \,km\,s^{-1}. These results agree with other systems showing a relationship between the radio relics and shock fronts which are induced by merging activity. We compare the X-ray derived Mach numbers with the radio derived Mach numbers from the radio spectral index under the assumption of diffusive shock acceleration in the linear test particle regime. For the northern radio relic, the Mach numbers derived from X-ray and radio observations agree with each other. Based on the shock velocities, we estimate that CIZA J2242.8+5301 is observed approximately 0.6 Gyr after core passage. The magnetic field pressure at the northern relic is estimated to be 9% of the thermal pressure.Comment: 12 pages, 10 figures, A&A accepte

    Confirming the Detection of an Intergalactic X-ray Absorber Toward PKS 2155-304

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    We present new observations on PKS 2155-304 with the Chandra Low Energy Transmission Grating Spectrometer (LETG), using the Advanced CCD Imaging Spectrometer (ACIS). We confirm the detection of an absorption line plausibly identified as OVIII Ly-alpha from the warm-hot intergalactic medium associated with a small group of galaxies along the line of sight, as originally reported by Fang et al. 2002 (here after FANG02). Combining the previous observations in FANG02 and five new, long observations on the same target, we increase the total exposure time by a factor of three, and the total counts per resolution element by a factor of five. The measured line equivalent width is smaller than that observed in FANG02, but still consistent at 90% confidence. We also analyze the XMM-Newton observations on the same target, as well as observations using the Chandra LETG and the High Resolution Camera (HRC) combination. These observations have been used to challenge our reported detection. While no line is seen in either the XMM-Newton and the Chandra LETG+HRC data, we find that our result is consistent with the upper limits from both data sets. We attribute the non-detection to (1) higher quality of the Chandra LETG+ACIS spectrum, and (2) the rather extended wings of the line spread functions of both the XMM RGS and the Chandra LETG+HRC. We discuss the implication of our observation on the temperature and density of the absorber. We also confirm the detection of z ~ 0 OVII absorption and, comparing with previous Chandra analysis, we obtain much tighter constraints on the line properties.Comment: 10 pages, 8 figures, accepted for publication in Ap
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