3,046 research outputs found

    Localization of matters on thick branes

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    AbstractWe study localization of various spin fields on flat thick branes, two different models are considered. For spin 0 scalar field, the massless zero mode is found to be normalizable on both the thick brane models. Spin 1 vector field cannot be normalizable on either of the two brane models. And for spin 1/2 field there is no bound zero mode for both the left and right chiral fermions. In order to localize the left or right chiral fermions on the thick brane models, the usual Yukawa scalar-fermion coupling is considered. It is shown that, the two models give different localization properties for fermions. Namely, whether there is a bound zero mode is related to the considered model

    Localization of matters on thick branes

    Get PDF
    AbstractWe study localization of various spin fields on flat thick branes, two different models are considered. For spin 0 scalar field, the massless zero mode is found to be normalizable on both the thick brane models. Spin 1 vector field cannot be normalizable on either of the two brane models. And for spin 1/2 field there is no bound zero mode for both the left and right chiral fermions. In order to localize the left or right chiral fermions on the thick brane models, the usual Yukawa scalar-fermion coupling is considered. It is shown that, the two models give different localization properties for fermions. Namely, whether there is a bound zero mode is related to the considered model

    Generalized Preconditioned MHSS Method for a Class of Complex Symmetric Linear Systems

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    Based on the modified Hermitian and skew-Hermitian splitting (MHSS) and preconditioned MHSS (PMHSS) methods, a generalized preconditioned MHSS (GPMHSS) method for a class of complex symmetric linear systems is presented. Theoretical analysis gives an upper bound for the spectral radius of the iteration matrix. From a practical point of view, we have analyzed and implemented inexact GPMHSS (IGPMHSS) iteration, which employs Krylov subspace methods as its inner processes. Numerical experiments are reported to confirm the efficiency of the proposed methods

    Gamma-Ray Burst/Supernova Associations: Energy Partition and the Case of a Magnetar Central Engine

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    The favored progenitor model for Gamma-ray Bursts (GRBs) with Supernova (SN) association is the core collapse of massive stars. One possible outcome of such a collapse is a rapidly spinning, strongly magnetized neutron star ( magnetar ). We systematically analyze the multi-wavelength data of GRB/SN associations detected by several instruments before 2017 June. Twenty GRB/SN systems have been confirmed via direct spectroscopic evidence or a clear light curve bump, as well as some spectroscopic evidence resembling a GRB-SN. We derive/collect the basic physical parameters of the GRBs and the SNe, and look for correlations among these parameters. We find that the peak brightness, 56Ni mass, and explosion energy of SNe associated with GRBs are statistically higher than other Type Ib/c SNe. A statistically significant relation between the peak energy of GRBs and the peak brightness of their associated SNe is confirmed. No significant correlations are found between the GRB energies (either isotropic or beaming-corrected) and the supernova energy. We investigate the energy partition within these systems and find that the beaming-corrected GRB energy of most systems is smaller than the SN energy, with less than 30% of the total energy distributed in the relativistic jet. The total energy of the systems is typically smaller than the maximum available energy of a millisecond magnetar (2 × 1052 erg), especially if aspherical SN explosions are considered. The data are consistent with—although not proof of—the hypothesis that most, but not all, GRB/SN systems are powered by millisecond magnetars
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