13,428 research outputs found

    Separability and radial asymptotic behaviour of the Dirac equation and integral spectral representation for the Dirac propagator in the 5D Myers-Perry geometry in Eddington-Finkelstein-type coordinates

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    We analytically extend the 5D Myers-Perry metric through the event and Cauchy horizons by defining Eddington-Finkelstein-type coordinates. We then use the orthonormal frame formalism to formulate and perform separation of variables on the massive Dirac equation, and analyse the asymptotic behaviour at the horizons and at infinity of the solutions to the radial ODE thus obtained, as was done by R\"oken in the Kerr geometry. Using the essential self-adjointness result of Finster and R\"oken and Stone's formula, we obtain an integral spectral representation of the Dirac propagator in terms of resolvents of the Dirac Hamiltonian, which can in turn be expressed in terms of Green's functions of the radial ODE.Comment: 22 page

    Local Dirac energy decay in the 5D Myers-Perry geometry using an integral spectral representation for the Dirac propagator

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    We consider the massive Dirac equation in the exterior region of the 5-dimensional Myers-Perry black hole. Using the resulting ODEs obtained from the separation of variables of the Dirac equation, we construct an integral spectral representation for the solution of the Cauchy problem with compactly supported smooth initial data. We then prove that the probability of presence of a Dirac particle to be in any compact region of space decays to zero as tt\to\infty, in analogy with the case of the Dirac operator in the Kerr-Newman geometry.Comment: 13 pages, fixed typographic error

    The dependence of the IR-radio correlation on the metallicity

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    We have compiled a sample of 26 metal-poor galaxies with 12 + log(O/H) < 8.1 with both infrared continuum and 1.4 GHz radio continuum data. By comparing to galaxies at higher metallicity, we have investigated the dependence on the metallicity of the IR-radio relationship at 24 um, 70 um, 100 um and 160 um bands as well as the integrated FIR luminosity. It is found that metal-poor galaxies have on average lower qIR than metal-rich ones with larger offsets at longer IR wavelengths, from -0.06 dex in q24um to -0.6 dex in q160um. The qIR of all galaxies as a whole at 160 um show positive trends with the metallicity and IR-to-FUV ratio, and negative trends with the IR color, while those at lower IR wavelengths show weaker correlations. We proposed a mechanism that invokes combined effects of low obscured-SFR/total-SFR fraction and warm dust temperature at low metallicity to interpret the above behavior of qIR, with the former reducing the IR radiation and the latter further reducing the IR emission at longer IR wavelength. Other mechanisms that are related to the radio emission including the enhanced magnetic field strength and increased thermal radio contribution are unable to reconcile the IR-wavelength-dependent differences of qIR between metal-poor and metal- rich galaxies. In contrast to qIR, the mean total-SFR/radio ratio of metal-poor galaxies is the same as the metal-rich one, indicating the 1.4 GHz radio emission is still an effective tracer of SFRs at low metallicity.Comment: 25 pages, 11 figures, 4 tables. ApJ in pres

    Index filtering and view materialization in ROLAP environment

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    2-Methyl-2,4-di-4-pyridyl-2,3-dihydro-1H-1,5-benzodiazepine acetic acid solvate

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    In the title compound, C20H18N4·CH3COOH, the benzene ring forms dihedral angles of 81.34 (11) and 54.32 (11)° with the two pyridine rings. In the crystal, inter­molecular O—H⋯N hydrogen bonding links one 1,5-benzodiazepine mol­ecule and one acetic acid solvent mol­ecule into a dimer. These dimers, related by translation along the b axis, are further linked into chains via weak inter­molecular N—H⋯N hydrogen bonds

    Comparison of the short term therapeutic effects by different incision triple surgery in treating angle-closure glaucoma with cataract

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    AIM:To compare the therapeutic effects of different incision phacoemulsification with foldable intraocular lens implantation combined with trabeculectomy in treating angle-closure glaucoma complicated with cataract. <p>METHODS: The retrospective study analyzed 70 patients(98 eyes)who performed phacoemulsification with foldable intraocular lens implantation combined with trabeculectomy. Single incision surgery(one-site approach)was performed on 34 patients(50 eyes), and double incision surgery(two-site approaches)was done on 36 patients(48 eyes). The differences of intraocular pressure control,filtering bleb, the density and preservation of corneal endothelium cells both pre-surgery and 1 month post-surgery or later complication. in the two groups were compared and analyzed.Follow-up was 12-24 months with a mean of 18.2 months.<p>RESULTS: The average postoperative intraocular pressure in one-site groups was(10.16±4.31)mmHg. The average postoperative intraocular pressure in two-site groups was(11.38±3.55)mmHg. There were no statistically significant differences between the two groups(<i>P</i>>0.05)regarding the postoperative intraocular pressure and the formation of filtering blebs(<i>P</i>>0.05). The density and area of corneal endothelium cells in the two-incision group pre-operation were comparable(<i>P</i>>0.05). However, in 1 month post-operation, the rate of the corneal endothelial cells loss in double incision group was superior compared to the single incision group(<i>P</i><0.01).<p>CONCLUSION: Both single incision and double incision approach phacotrabeculectomy are effective in reducing intraocular pressure and can maintain the function of filtering blebs well. There are no statistically significant differences in the intraocular pressure reduction between the two approaches. The double incision approach is superior in minimizing the corneal endothelial cells loss compared to the single incision approach
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