Pure Thermal Spectrum Research Articles

Hawking radiation as tunneling from the Kerr and Kerr-Newman black holes

Recent work, which treats the Hawking radiation as a semiclassical tunneling process at the horizon of the Schwarzschild and Reissner-Nordstr\om spacetimes, indicates that the exact radiant spectrum is no longer pure thermal after considering the black hole background as dynamical and the conservation of energy. In this paper, we extend the method to investigate Hawking radiation as massless particles tunneling across the event horizon of the Kerr black hole and that of charged particles from the Kerr-Newman black hole by taking into account the energy conservation, the angular momentum conservation, and the electric charge conservation. Our results show that when self-gravitation is considered, the tunneling rate is related to the change of Bekenstein-Hawking entropy and the derived emission spectrum deviates from the pure thermal spectrum, but is consistent with an underlying unitary theory.

Hawking radiation of charged particles via tunneling from the Reissner-Nordström black hole

Hawking radiation is viewed as a tunneling process. In this way the emission rate at which charged massive particles tunnel across the event horizon of the Reissner-Nordstrom black hole is calculated. The emission spectrum deviates from the pure thermal spectrum, but it is consistent with an underlying unitary theory and takes the same functional form as that of uncharged massless particles.

Pile oscillator measurements of resonance absorption integrals

Measurements of the resonance absorption integral cross-sections of some thirty-five materials are reported. The effective cross-sections of the materials concerned were measured by the Dimple pile oscillator in both a pure thermal neutron spectrum and in one with an appreciable epithermal component, the difference between the cross-sections found in these two cases leading directly to the resonance absorption integral. Experiments have also been performed to measure the amount of self-screening in many of the samples. The cross-sections are compared with other experimental results, and also with estimates of the resonance integrals deduced from resonance parameter data.