共查询到19条相似文献,搜索用时 921 毫秒
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在直线加速Kinnersley时空中,将相互耦合的Dirac方程化为二阶方程,采用新的乌龟坐标变换,在视界面附近消除二阶方程中的耦合化成了标准波动方程,得到辐射温度函数和Hawking热辐射谱. 相似文献
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在任意加速带电动态时空中,选取零标架、计算出旋系数,把四个耦合的Dirac方程中化成两个耦合的方程,采用Tortoise坐标变换将其两个耦合的方程变换成Tortoise坐标下的形式,在黑洞视界面附近化成了典型的波动方程,得到在视界面附近Dirac粒子的Hawking辐射温度,成功地导出了Hawking热谱公式.
关键词:
Dirac方程
Hawking辐射
黑洞
Tortoise坐标变换 相似文献
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采用两种新的乌龟坐标变换,用改进的Damour-Ruffini方法研究了动态Kinnersley黑洞的Hawking辐射.在新乌龟坐标变换下,将Klein-Gordon方程在视界附近变换成平直时空的标准波动方程形式,得到了黑洞的表面引力及Hawking温度,该温度在黑洞表面不同点有不同的值.值得注意的是,旧的乌龟坐标变换存在量纲错误,新乌龟坐标变换没有量纲问题,选不同的旧乌龟坐标变换计算同一黑洞所得结果不同,但是采用不同的新乌龟坐标变换所得结果仍然不同.
关键词:
黑洞
乌龟坐标变换
Hawking辐射
Klein-Gorden方程 相似文献
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本文用一种新的乌龟坐标变换和改进的Damour-Ruffini方法研究了动态Kerr黑洞的Hawking辐射,得到了随时间和纬度角而变化的局域温度和具有准黑体谱形式的Hawking辐射谱.其结果与采用通常的乌龟坐标变换所得结果有所不同,而通常的乌龟坐标变换在量纲上存在一定的问题,本文的结果也许更为合理.
关键词:
Hawking辐射
动态Kerr黑洞
改进的Damour-Ruffini方法
新乌龟坐标变换 相似文献
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本文研究任意Kerr-Newman黑洞视界曲面上荷电Dirac粒子的Hawking辐射,首先构造了一套“对称零标架”,用这套零标架计算了旋系数,导出了Dirac方程,在视界曲面附近解Dirac方程。得到荷电Dirac粒子四分量波函数的显示表式。利用解析延拓技巧,最后得到荷电Dirac粒子Hawking辐射的热谱公式。
关键词: 相似文献
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在一般加速带电带磁的动态黑洞中,化简Klein-Gordon场方程,利用乌龟坐标变换,得到在视界面附近的辐射温度.用薄膜brick-wall模型,选择适当的截断因子和薄膜厚度,得到在视界面附近薄膜上的熵,结果表明黑洞熵与视界面积成正比.
关键词:
黑洞
Hawking温度
薄膜brick-wall模型
熵 相似文献
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基于图像的飞行器红外辐射特性测量 总被引:3,自引:0,他引:3
通过将目标在一定波段内的红外辐射等效为红外成像系统前一定距离下黑体在对应波段内的红外辐射,建立了等效辐射方程。根据黑体辐射定标实验数据,利用非线性回归方法确定了在不同的积分时间条件下红外凝视成像系统输出红外图像的灰度值与在一定距离下的黑体温度之间的定量关系,建立了辐射定标方程。在Visual C++6.0平台下,在对红外目标图像进行SUSAN滤波等预处理后,分析了已知目标距离的红外图像的灰度均值。首先根据辐射定标方程计算出目标等效为黑体的温度,然后利用等效辐射方程反推目标的红外辐射强度,以达到根据跟踪的红外图像确定红外目标辐射特性的目的。此项研究不仅可以为目标识别提供目标分类、识别和辨认所必需的光谱数据库,而且还可以为红外预警提供重要的参考数据。 相似文献
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P.K. Shukla 《Physics letters. A》2011,375(3):577-578
It is shown that a pre-existing dust ripple in a dusty plasma may excite tunable electromagnetic radiation. For our purposes, we use the Maxwell equation and the electron equation of motion to derive a Mathieu equation in the presence of a spatially oscillating dust ripple. The Mathieu equation admits instability of an electromagnetic wave. Criteria under which instability occurs are presented. Explicit expression for the electromagnetic radiation frequency and the growth rate are obtained. The possible relevance of our investigation to nonthermal electromagnetic radiation sources from laboratory and cosmic dusty plasmas is considered. 相似文献
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K. P. Gaikovich 《Radiophysics and Quantum Electronics》2003,46(4):239-248
It is shown that the one-dimensional problem of near-field microwave radiometry in the case of a smoothly inhomogeneous medium can be reduced to an integral equation similar to the well-known solution of the radiation transfer equation. The kernel of this integral equation depends on only one parameter determined experimentally. This makes it possible to determine the subsurface temperature profiles by using a set of near-field antennas of arbitrary design for which the sounding-depth range is overlapped by the effective depth of formation of the radiation received by these antennas. In the case of near-field measurements, the previously obtained joint solution of the radiation transfer equation and the thermal diffusion equation can also be modified and applied for monitoring the subsurface temperature profile using the temporal dependence of the received signal. 相似文献
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Dimitri Mihalas Robert Weaver 《Journal of Quantitative Spectroscopy & Radiative Transfer》1982,28(3):213-222
We discuss a simple method for solving the time-dependent transfer problem. This scheme is automatically flux-limited and affords physical insight into how flux limitation occurs. We then develop a second-order, time-dependent radiation energy equation that is similar in form to the diffusion limit radiation energy equation. This time-dependent energy equation approaches physically reasonable equations in optically thick and thin regions. Computational aspects of solving this energy equation are discussed. 相似文献
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Yu. N. Barabanenkov M. Yu. Barabanenkov 《Journal of Experimental and Theoretical Physics》1998,86(2):237-243
The propagation of a quasimonochromatic wave packet of acoustic radiation in a discrete randomly-inhomogeneous medium under
the condition that the carrier frequency of the packet is close to the resonance frequency of Mie scattering by an isolated
scatterer is studied. The two-frequency Bethe-Salpeter equation in the form of an exact kinetic equation that takes account
of the accumulation of the acoustic energy of the radiation inside the scatterers is taken as the initial equation. This kinetic
equation is simplified by using the model of resonant point scatterers, the approximation of low scatterer density, and the
Fraunhofer approximation in the theory of multiple scattering of waves. This leads to a new transport equation for nonstationary
radiation with three Lorentzian delay kernels. In contrast to the well-known Sobolev radiative transfer equation with one
Lorentzian delay kernel, the new transfer equation takes account of the accumulation of radiation energy inside the scatterers
and is consistent with the Poynting theorem for nonstationary acoustic radiation. The transfer equation obtained with three
Lorentzian delay kernels is used to study the Compton-Milne effect—trapping of a pulse of acoustic radiation diffusely reflected
from a semi-infinite resonant randomly-inhomogeneous medium, when the pulse can spend most of its propagation time in the
medium being “trapped” inside the scatterers. This specific albedo problem for the transfer equation obtained is solved by
applying a generalized nonstationary invariance principle. As a result, the function describing the scattering of a diffusely
reflected pulse can be expressed in terms of a generalized nonstationary Chandrasekhar H-function, satisfying a nonlinear integral equation. Simple analytical asymptotic expressions are found for the scattering
function for the leading and trailing edges of a diffusely reflected δ-pulse as functions of time, the reflection angle, the mean scattering time of the radiation, the elementary delay time, and
the parameter describing the accumulation of radiation energy inside the scatterers. These asymptotic expressions demonstrate
quantitatively the retardation of the growth of the leading edge and the retardation of the decay of the trailing edge of
a diffusely reflected δ-pulse when the conventional radiative transfer regime goes over to a regime of radiation trapping in a resonant randomly-inhomogeneous
medium.
Zh. éksp. Teor. Fiz. 113, 432–444 (February 1998) 相似文献
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