123 research outputs found

    Geometric Quantization on a Coset Space G/H

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    Geometric quantization on a coset space G/HG/H is considered, intending to recover Mackey's inequivalent quantizations. It is found that the inequivalent quantizations can be obtained by adopting the symplectic 2-form which leads to Wong's equation. The irreducible representations of HH which label the inequivalent quantizations arise from Weil's theorem, which ensures a Hermitian bundle over G/HG/H to exist.Comment: 12 pages, LateX2

    Single-epoch supernova classification with deep convolutional neural networks

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    Supernovae Type-Ia (SNeIa) play a significant role in exploring the history of the expansion of the Universe, since they are the best-known standard candles with which we can accurately measure the distance to the objects. Finding large samples of SNeIa and investigating their detailed characteristics have become an important issue in cosmology and astronomy. Existing methods relied on a photometric approach that first measures the luminance of supernova candidates precisely and then fits the results to a parametric function of temporal changes in luminance. However, it inevitably requires multi-epoch observations and complex luminance measurements. In this work, we present a novel method for classifying SNeIa simply from single-epoch observation images without any complex measurements, by effectively integrating the state-of-the-art computer vision methodology into the standard photometric approach. Our method first builds a convolutional neural network for estimating the luminance of supernovae from telescope images, and then constructs another neural network for the classification, where the estimated luminance and observation dates are used as features for classification. Both of the neural networks are integrated into a single deep neural network to classify SNeIa directly from observation images. Experimental results show the effectiveness of the proposed method and reveal classification performance comparable to existing photometric methods with multi-epoch observations.Comment: 7 pages, published as a workshop paper in ICDCS2017, in June 201

    A New Insight into Electron Acceleration Properties from Theoretical Modeling of Double-Peaked Radio Light Curves in Core-Collapse Supernovae

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    It is recognized that some core-collapse supernovae (SNe) show a double-peaked radio light curve within a few years since the explosion. A shell of circumstellar medium (CSM) detached from the SN progenitor has been considered to play a viable role in characterizing such a re-brightening of radio emission. Here, we propose another mechanism that can give rise to the double-peaked radio light curve in core-collapse SNe. The key ingredient in the present work is to expand the model for the evolution of the synchrotron spectral energy distribution (SED) to a generic form, including fast and slow cooling regimes, as guided by the widely-accepted modeling scheme of gamma-ray burst afterglows. We show that even without introducing an additional CSM shell, the radio light curve would show a double-peaked morphology when the system becomes optically thin to synchrotron self-absorption at the observational frequency during the fast cooling regime. We can observe this double-peaked feature if the transition from fast cooling to slow cooling regime occurs during the typical observational timescale of SNe. This situation is realized when the minimum Lorentz factor of injected electrons is initially large enough for the non-thermal electrons' SED to be discrete from the thermal distribution. We propose SN 2007bg as a special case of double-peaked radio SNe that can be explained by the presented scenario. Our model can serve as a potential diagnostic for electron acceleration properties in SNe.Comment: 16 pages, 8 figures, submitted to Ap

    Nonlocally-correlated disorder and delocalization in one dimension II: Localization length

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    In the previous paper (cond-mat/9809323), we calculated the density of staes in the random-mass Dirac fermion system. In this paper, we obtain the mean localization length of the single-fermion Greem's function by using the supersymmetric methods. It is shown that the localization length is a increasing function of the correation length of the disorders. This result is in agreement with the density of states and the numerical studies (cond-mat/9903389).Comment: Latex, 25 page

    A pilot trial of an online guided self-help cognitive behavioral therapy program for bulimia nervosa and binge eating disorder in Japanese patients

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    BackgroundThe purpose of this study was to develop an internet-based Guided Self-Help CBT (iGSH-CBT) for Bulimia Nervosa (BN) / Binge Eating Disorder (BED) for Japanese patients and to test its feasibility.MethodsA single-arm feasibility study. After baseline assessment, patients underwent a 16-week iGSH-CBT program, our Japanese adaption of the European-based Salut BN program. During the treatment period, weekly email support from trained counselors was provided. Evaluations were performed at baseline, after 8 weeks, at the end of the 16-week intervention, and at 2 months after treatment had ended. The primary outcome measure was the change in the weekly frequency of objective binging. Secondary outcomes were the change in the weekly frequency of objective purge episodes, responses on self-report questionnaires of the frequencies of binging and purging, psychopathological characteristics of eating disorders found on BITE, EDE-Q, EDI-2, HADS and EQ-5D, measurements of motivation, and completion of intervention (vs. dropout).ResultsParticipants were 9 female outpatients with BN (n = 5) or BED (n = 4), of whom 8 (88.9%) attended the assessment at the end of the 16-week intervention. Mean age was 28 years (SD = 7.9). Percent change of the weekly frequency of objective binging was -4.40%, and at the end of the 16-week intervention 25% of the participants had achieved symptom abstinence.ConclusionsNo adverse events were observed during the treatment period and follow-up, and the implementation and operation of the program could be performed without any major problems, confirming the feasibility of iGSH-CBT for BN and BED for Japanese patients. Although no significant change was observed in the weekly frequency of objective binging, the abstinence rate from bulimic behaviors of those who completed the assessments was 25.0% at the end of treatment, and the drop-out rate was 11.1%. iGSH-CBT may be an acceptable and possibly even a preferred method of CBT delivery for Japanese patients with BN or BED, and our Japanese adaptation of Salut BN seems feasible.Trial registrationUMIN, UMIN000031962. Registered 1 April 2018 - Retrospectively registered, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R00003633

    Localized and Extended States in One-Dimensional Disordered System: Random-Mass Dirac Fermions

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    System of Dirac fermions with random-varying mass is studied in detail. We reformulate the system by transfer-matrix formalism. Eigenvalues and wave functions are obtained numerically for various configurations of random telegraphic mass m(x). Localized and extended states are identified. For quasi-periodic m(x), low-energy wave functions are also quasi-periodic and extended, though we are not imposing the periodic boundary condition on wave function. On increasing the randomness of the varying mass, states lose periodicity and most of them tend to localize. At the band center or the low-energy limit, there exist extended states which have more than one peak spatially separate with each other comparatively large distance. Numerical calculations of the density of states and ensemble averaged Green's functions are explicitly given. They are in good agreement with analytical calculations by using the supersymmetric methods and exact form of the zero-energy wave functions.Comment: 27 pages, including 8 EPS figure
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