What Makes a Utopia Inconvenient? On the Advantages and Disadvantages of a Realist Orientation to Politics

Contemporary politics is often said to lack utopias. For prevailing understandings of the practical force of political theory, this looks like cause for celebration. As blueprints to apply to political practice, utopias invariably seem too strong or too weak. Through an immanent critique of political realism, I argue that utopian thought, and political theory generally, is better conceived as supplying an orientation to politics. Realists including Bernard Williams and Raymond Geuss explain how utopian programs like universal human rights poorly orient their adherents to politics, but the realists wrongly conclude that utopias and other ideal theories necessarily disorient us. As I show through an analysis of utopian claims made by Michel Foucault, Malcolm X, and John Rawls, utopias today can effectively disrupt entrenched forms of legitimation, foster new forms of political identity, and reveal new possibilities within existing institutions. Utopias are needed to understand the political choices we face today

Dynamics of mistuned radial turbine wheels

This paper presents investigations carried out at Holset into the dynamics of mistuned radial turbine wheels, including a literature review, a lumped parameter model, identification of the most responsive blade, distribution of the peak maximum order response and a method of mistiming identification

New molecular candidates: X(1910), X(2200), and X(2350)

Assuming the newly observed resonant structures X(1910), X(2200), and X(2350) as $\omega\omega$, $\omega\phi$, and $\phi\phi$ molecular states respectively, we compute their mass values in the framework of QCD sum rules. The numerical results are $1.97\pm0.17 {GeV}$ for $\omega\omega$ state, $2.07\pm0.21 {GeV}$ for $\omega\phi$ state, and $2.18\pm0.29 {GeV}$ for $\phi\phi$ state, which coincide with the experimental values of X(1910), X(2200), and X(2350), respectively. This supports the statement that X(1910), X(2200), and X(2350) could be $\omega\omega$, $\omega\phi$, and $\phi\phi$ molecular candidates respectively.Comment: 9 pages, 9 eps figures; the name of X(2000) changed to X(1910) according to the updated data of experiments; more references and discussions added; accepted for publication in PRD. arXiv admin note: substantial text overlap with arXiv:1211.2277, arXiv:1201.341

X(1835), X(2120) and X(2370) in a flux tube model

Nonstrange baryonium spectrum is systematically studied by using the Gaussian expansion method in a flux tube model with the six-body confinement potential. All the model parameters are fixed by baryon properties, so the baryonium calculation is parameter-free. We find that X(1835) and X(2370), which are observed in the radiative decay of $J/\psi$ by BES collaboration, can be described as $N_8\bar{N}_8$ and $\Delta_8\bar{\Delta}_8$ bound states with quantum numbers $I^GJ^{PC}=0^+0^{-+}$, respectively, such bound states should be color confinement resonances with three-dimensional configurations similar to dumbbell, however, X(2120) can not be accommodated in our model.Comment: 6 pages, 1 figure. arXiv admin note: text overlap with arXiv:1201.176

Very deep spectroscopy of the bright Saturn Nebula NGC 7009 -- I. Observations and plasma diagnostics

We present very deep CCD spectrum of the bright, medium-excitation planetary nebula NGC 7009, with a wavelength coverage from 3040 to 11000 A. Traditional emission line identification is carried out to identify all the emission features in the spectra, based on the available laboratory atomic transition data. Since the spectra are of medium resolution, we use multi-Gaussian line profile fitting to deblend faint blended lines, most of which are optical recombination lines (ORLs) emitted by singly ionized ions of abundant second-row elements such as C, N, O and Ne. Computer-aided emission-line identification, using the code EMILI developed by Sharpee et al., is then employed to further identify all the emission lines thus obtained. In total about 1200 emission features are identified, with the faintest ones down to fluxes 10^{-4} of H_beta. The flux errors for all emission lines, estimated from multi-Gaussian fitting, are presented. Plots of the whole optical spectrum, identified emission lines labeled, are presented along with the results of multi-Gaussian fits. Plasma diagnostics using optical forbidden line ratios are carried out. Also derived are electron temperatures and densities from the H I, He I and He II recombination spectrum.Comment: 66 pages, 16 figures, 7 tables, paper accepted by MNRAS in Marc

Ricci flow on K\"ahler-Einstein manifolds

In our previous paper math.DG/0010008, we develop some new techniques in attacking the convergence problems for the K\"ahler Ricci flow. The one of main ideas is to find a set of new functionals on curvature tensors such that the Ricci flow is the gradient like flow of these functionals. We successfully find such functionals in case of Kaehler manifolds. On K\"ahler-Einstein manifold with positive scalar curvature, if the initial metric has positive bisectional curvature, we prove that these functionals have a uniform lower bound, via the effective use of Tian's inequality. Consequently, we prove the following theorem: Let $M$ be a K\"ahler-Einstein manifold with positive scalar curvature. If the initial metric has nonnegative bisectional curvature and positive at least at one point, then the K\"ahler Ricci flow will converge exponentially fast to a K\"ahler-Einstein metric with constant bisectional curvature. Such a result holds for K\"ahler-Einstein orbifolds.Comment: 49 pages. This is a revised version. Sections 4 and 5 are simplified and streamline