According to a corrected dispersion relation proposed in the study on the string theory and quantum gravity theory,the Rarita-Schwinger equation was precisely modified,which resulted in the Rarita-Schwinger-Hamilton-Jacobi equation.Using this equation,the characteristics of arbitrary spin fermion quantum tunneling radiation from non-stationary Kerr-de Sitter black holes were determined.A number of accurately corrected physical quantities,such as surface gravity,chemical potential,tunneling probability,and Hawking temperature,which describe the properties of black holes,were derived.This research has enriched the research methods and enabled increased precision in black hole physics research.
When a daughter nucleus produced by electron capture takes part in a level transition from an excited state to its ground state in accreting neutron star crusts, thermal energy will be released and heat the crust, increasing crust temperature and changing subsequent carbon ignition conditions. Previous studies show that the theoretical carbon ignition depth is deeper than the value inferred from observations because the thermal energy is not sufficient. In this paper, we present the de-excited energy from electron capture of rp-process ash before carbon ignition, especially for the initial evolution stage of rp-process ash, by using a level-to-level transition method. We find the theoretical column density of carbon ignition in the resulting superbursts and compare it with observations. The calculation of the electron capture process is based on a more reliable level-to-level transition, adopting new data from experiments or theoretical models(e.g., large-scale shell model and proton-neutron quasi-particle random phase approximation). The new carbon ignition depth is estimated by fitting from previous results of a nuclear reaction network. Our results show the average de-excited energy from electron capture before carbon ignition is ~0.026 Me V/u, which is significantly larger than the previous results. This energy is beneficial for enhancing the crust’s temperature and decreasing the carbon ignition depth of superbursts.
The distribution of abundance for iron-peak elements in dwarf spheroidal galaxies(d Sphs) is important for galaxy evolution and supernova(SN) nucleosynthesis. Nowadays, manganese(Mn) is one of the most observed iron-peak elements in local d Sphs. Studies of its distributions allow us to derive and understand the evolution history of these d Sphs. We improve a phenomenological model by a two-curve model including a new initial condition, that includes detailed calculations of SN explosion rates and yields. We compare the results with the observed Mn distribution data for three d Sphs: Fornax, Sculpture and Sextans.We find that the model can describe the observed Fe and Mn distributions well simultaneously for the three d Sphs. The results also indicate that the initial conditions should be determined by the low metallicity samples in the beginning time of the galaxies and the previous assumption of metellicity-dependant Mn yield of SNIa is not needed when a wide mass range of core-collapse SNe is included. Our method is applicable to the chemical evolution of other iron-peak elements in d Sphs and can be modified to provide more detailed processes for the evolution of dSphs.
Effects of an ultra-strong magnetic field on electron capture rates for55 Co are analyzed in the nuclear shell model and under the Landau energy levels quantized approximation in the ultra-strong magnetic field, and the electron capture rates on 10 abundant iron group nuclei at the surface of a magnetar are given. The results show that electron capture rates on 55Co are increased greatly in the ultra-strong magnetic field, by about 3 orders of magnitude generally. These conclusions play an important role in future study of the evolution of magnetars.
Based on a light dispersion relationship derived from string theory and quantum gravitational theory,we make an accurate modification to the quantum tunneling radiation rate and black hole temperature at an event horizon in a stationary axial-symmetric Einstein–Maxwell–dilaton–axion black hole.We also analyze our new results and carry out some significant discussions.This work enriches the research content and methods of the frontiers of black hole physics.
