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81.
No Heading The Evans field equation is solved to give the equations governing the evolution of scalar curvature R and contracted energy-momentum T. These equations show that R and T are always analytical, oscillatory, functions without singularity and apply to all radiated and matter fields from the sub-atomic to the cosmological level. One of the implications is that all radiated and matter fields are both causal and quantized, contrary to the Heisenberg uncertainty principle. The wave equations governing this quantization are deduced from the Evans field equation. Another is that the universe is oscillatory without singularity, contrary to contemporary opinion based on singularity theorems. The Evans field equation is more fundamental than, and leads to, the Einstein field equation as a particular example, and so modifies and generalizes the contemporary Big Bang model. The general force and conservation equations of radiated and matter fields are deduced systematically from the Evans field equation. These include the field equations of electrodynamics, dark matter, and the unified or hybrid field. 相似文献
82.
Among the several proposals to solve the incompatibility between the observed small value of the cosmological constant and the huge value obtained by quantum field theories, we can find the idea of a decaying vacuum energy density, leading from high values at early times of universe evolution to the small value observed nowadays. In this paper we consider a variation law for the vacuum density recently proposed by Schützhold on the basis of quantum field estimations in the curved, expanding background, characterized by a vacuum density proportional to the Hubble parameter. We show that, in the context of an isotropic and homogeneous, spatially flat model, the corresponding solutions retain the well established features of the standard cosmology, and, in addition, are in accordance with the observed cosmological parameters. Our scenario presents an initial phase dominated by radiation, followed by a dust era long enough to permit structure formation, and by an epoch dominated by the cosmological term, which tends asymptotically to a de Sitter universe. Taking the matter density equals to half of the vacuum energy density, as suggested by observation, we obtain a universe age given by Ht = 1.1, and a decelerating parameter equals to −1/2. 相似文献
83.
P C Vaidya 《Pramana》1977,8(6):512-517
A metric satisfying Einstein’s equations is given which in the vicinity of the source reduces to the well-known Kerr metric
and which at large distances reduces to the Robertson-Walker metric of a homogeneous cosmological model. The radius of the
event horizon of the Kerr black hole in the cosmological background is found out. 相似文献
84.
85.
A sufficiently convenient set theory in the standard -language applicable to nonstandard analysis is proposed. 相似文献
86.
Current universe (assumed here to be normal matter on the brane) is
pressureless from observations. In this case the energy condition is
ρ0≥0 and p0=0. By using this condition, brane models can be distinguished. Then, assuming arbitrary component of matter in
DGP model, we use four known energy conditions to study the matter
on the brane. If there is nonnormal matter or energy (for example
dark energy with w<-1/3) on the brane, the universe is accelerated. 相似文献
87.
M. C. Stanley 《Annals of Pure and Applied Logic》2001,110(1-3):23-87
It is shown that there is no satisfactory first-order characterization of those subsets of ω2 that have closed unbounded subsets in ω1,ω2 and GCH preserving outer models. These “anticharacterization” results generalize to subsets of successors of uncountable regular cardinals. Similar results are proved for trees of height and cardinality κ+ and for partitions of [κ+]2, when κ is an infinite cardinal. 相似文献
88.
Recent trends in the research of quark gluon plasma (QGP) are surveyed and the current experimental and theoretical status
regarding the properties and signals of QGP is reported. We hope that the experiments commencing at relativistic heavy-ion
collider (RHIC) in 2000 will provide a glimpse of the QGP formation. 相似文献
89.
Mechanical properties of the thermal equilibrium Friedmann–Robertson–Walker universe model 下载免费PDF全文
The mechanical property of the thermal-equilibrium Friedmann-Robertson-Walker (TEFRW) universe is first studied. The equation of state and the scale factor of the TEFRW universe take the forms ofw = w(a;zT) and a = a(a;zT,Ho). For the universe consisting of the nonrelativistic matter and the dark energy, the behavior of the dark energy depends on the value of the present-day matter fraction. For the TEFRW universe consisting of N ingredients, the effective temperature is introduced. Lastly, a simple TEFRW universe model is analyzed. 相似文献
90.
膨胀石墨是一种具有潜在应用价值的红外/毫米波无源干扰一体化材料.本文依次以硝酸和磷酸、硝酸和乙酸的混酸为插层剂,高锰酸钾为氧化剂,采用分步插层法制备了不同体积膨胀率的膨胀石墨.采用扫描电镜分析了膨胀石墨微观结构随膨胀体积的变化;采用静态测试方法测试了不同体积膨胀率膨胀石墨的毫米波衰减性能.结果表明:随膨胀体积的增大,膨胀石墨层壁更薄,片层被充分打开,其有更多的微小薄片的尺度分布介于几微米到几十微米之间;膨胀石墨对毫米波的衰减性能随膨胀体积的增大而增大,当膨胀体积从233mL/g增大到450mL/g时,其3mm波衰减性能从5.7dB增大到8.68dB. 相似文献