Casimir效应的一个简明计算

电磁场的真空态具有无穷大的能量,这个无穷大能量不可直接观测,只在某些特殊情况下才表现出可观测的效应,其中之一便是Casimir效应,通常这个效应的计算是在量子场论中,按重正化的办法进行,这里给出一个更为简明的算法。     

掺杂硅片与电磁超材料间的Casimir平衡恢复力

为探讨掺杂硅片与电磁超材料间的Casimir平衡恢复力的大小与相关材料参数间的变化关系,基于Lifshitz理论,采用格林函数得到麦克斯韦应力张量及单位面积Casimir力计算表达式,分析了掺杂硅片与电磁超材料板间的Casimir作用力.结果表明,掺杂硅片与电磁超材料板间Casimir作用力的大小和方向随着掺杂程度、材料厚度和填充比例因子的变化而改变,并能调控Casimir效应;且随着板间距的变化表现出平衡恢复力.     

广义不确定关系与黑洞附近的热力学量

利用广义不确定关系修正的态密度计算了一般球对称静态黑洞附近无质量共形不变标量场、中微子场、电磁场、无质量Rarita-Schwinger场和引力场的热力学量.结果表明，黑洞附近的热力学量不仅依赖于黑洞的特征，还依赖于粒子的自旋和最小距离的尺度. 关键词： 广义不确定关系 一般球对称静态黑洞 热力学量     

掺杂硅片与电磁超材料间的Casimir平衡恢复力EI北大核心CSCD

为探讨掺杂硅片与电磁超材料间的Casimir平衡恢复力的大小与相关材料参数间的变化关系,基于Lifshitz理论,采用格林函数得到麦克斯韦应力张量及单位面积Casimir力计算表达式,分析了掺杂硅片与电磁超材料板间的Casimir作用力.结果表明,掺杂硅片与电磁超材料板间Casimir作用力的大小和方向随着掺杂程度、材料厚度和填充比例因子的变化而改变,并能调控Casimir效应;且随着板间距的变化表现出平衡恢复力.     

具有双旋转参数5维黑洞的Cardy-Verlinde公式

对具有双旋转参数的5维时空中,黑洞视界的热力学参量与宇宙视界的热力学参量进行了研究 .发现宇宙视界的熵能写为Cardy-Verlinde公式的形式,而黑洞视界的熵要写成Cardy-Verl inde公式的形式,必须用Abbott 和Deser的方法,计算具有双旋转参数5维黑洞的质量.通过研究,给出了具有双旋转参数5维黑洞各热力学参量之间满足的关系式,即热力学第一定律的微分式. 关键词： Cardy-Verlinde公式 Casimir能量 de Sitter时空     

量子多体系统的线性张量重正化群方法

文章简述了数值重正化群方法的历史发展,包括威耳逊（Wilson）的数值重正化群算法,S.R.White的密度矩阵重正化群方法,以及近期迅速发展的处理强关联量子系统的几种张量网络态与张量网络算法.在此基础上,文章重点介绍了作者最近提出的用于研究量子多体系统热力学性质的线性张量重正化群方法,以及该方法在一维和二维量子系统中的应用.     

R(5)群Casimir算子对核子JT耦合态的进一步分类

用R(5)群Casimir算子C对核子JT耦合态的进一步分类作了计算,并将JTC分类的重复度对J.T的依赖关系因子化,对j≤T/2列出了具体结果.由R(5)的不可约表示引入辛弱数υ和约化同位旋τ,利用υ和τ的选择定则可简化任意张量算子的矩阵元计算.     

在没有东西的空间中试探新的物理学

一般认为,真空是一个没有任何物质的空间,实际上真空内是充满着各种飞逝的粒子与电磁场的,现在已被证实在真空内存在着一种能使两块金属板相互吸引的力,这种力被称为 Casimir 力,它是一种量子现象.近来在考虑亚微米尺度内的物理现象时,例如研究各种力、各种粒子在不同维数下的问题时都不可避免地要考虑 Casimir 力.在一对只有狭窄间隔的金属平板空间内,它能保留的能量密度要比在金属平板外的能量密度低很多,这一点很类似于地下的隧道管,一般收音机的电波波长大于隧道口径时就无法收到信号,而在两块平板间同样也会阻止波长大于其间隔距离的…     

对《二维六角形晶格伊辛模型的重正化群解》一文的进一步计算

针对《二维六角形晶格伊辛模型的重正化群解》一文中有关〈V〉0的计算进行了修正,给出了新的重正化群的变换、重正化群的线性化变换矩阵以及临界指数.     

2+1维U(1)格点规范场论中真空态的研究

对2+1维U(1)格点规范场论真空态进行研究,仔细推导出连续极限下真空谈函数中参数μ₀和μ₂的普适表达式,并用截断本征方程法进行数值计算.     

Casimir Effect Under Two Dimensional Black Hole Spacetime Background with Global Monopole

A thin layer of the event horizon vicinity to the two-dimension black hole with a global monopole is considered as a system of the Casimir type. The energy-momentum tensor is derived in Boulware vacuum, Hartle-Hawking vacuum and Unruh vacuum respectively. The values are derived in the massless scalar field which satisfies the Dirichlet boundary conditions. Using the Wald's axioms, the result is got which is the same with the one derived by the usual regularized methods. Meanwhile, the energy, energy density, and pressure acting on the boundaries at the asymptotically flat background also are calculated too, and from the energy, Casimir force is derived. The Casimir energy and Casimir force are compared respectively in the background before and after radiation. PACS: 42.50.Lc.     

Vacuum polarization near a black hole creating particles

The renormalized expectation value of the energy-momentum tensor associated with scalar massless particles created by a Schwarzschild black hole is calculated by performing a numerical computation.     

Hawking effect in Vaidya-Bonner space-time

A new method determining the location and the temperature of event horizons of evaporating black holes is suggested. Both the Klein-Gordon equation and the Dirac equation are studied with the method in a Vaidya-Bonner space-time. These equations are reduced near the event horizon when the generalized tortoise coordinates are adopted. The location and the temperature of the event horizon are shown automatically. The first approximation of our result is the same as that obtained by using the calculation of the vacuum expectation value of the renormalized energy-momentum tensor when the evaporation of the black hole is very slow.     

On Thermodynamics of Kerr Black Hole

The gravitational Stefan–Boltzmann law is considered for the Kerr black hole in the weak-field limit. The energy-momentum tensor predicted by teleparallelism equivalent to general relativity is used in the thermo field dynamics formalism to thermalize the field. A temperature-dependent gravitational pressure is obtained. Regions of divergent heat capacity are observed. According to Landau theory, it allows the existence of distinct phases around the Kerr black hole.     

Vacuum expectation values of the energy-momentum tensor in two dimensions

A general form of the vacuum expectation values of the components of the energy-momentum tensor is derived in the case of static two-dimensional spacetime. Conditions for the regularity of the energy-momentum tensor are set. A generalized formula for the black hole temperature originally found by Hawking is given. The regularity of the energy-momentum tensor in the presence of more than one horizon is investigated.On leave of absence from the Institute of Mathematics, Polish Academy of Sciences, Warsaw, Poland.     

Casimir Energy in Hartle--Hawking State

We calculate the Casimir effect at finite temperature in Minkowski spacetime by using statistical method, the approximate expressions of the Casimir effect in the low and high temperature limits are also discussed. Then employing some general properties of the renormalized stress tensor, we obtain the Casimir energy stress tensor in Hattie-Hawking state.     

Hawking radiation from a general spherically symmetric evaporating black hole

By means of generalized tortoise coordinates both the Klein-Gordon equation and the Dirac equation are reduced near the event horizon of a general spherically symmetric evaporating black hole. The location and the temperature of the event horizon are given automatically without calculating the energy-momentum tensor. The Hawking thermal spectra of the Klein-Gordon particles and the Dirac particles are obtained, respectively.     

Renormalization in the theory of a quantized scalar field interacting with a robertson-walker spacetime

We demonstrate the possibility of removing the divergences in the energy-momentum tensor by identifying divergent terms with renormalizations of the coupling constants in the gravitational field equation, modified to include a cosmological term and terms quadratic in the curvature. The model studied is that of a classical Robertson-Walker metric and a quantized minimally coupled neutral scalar field. The theory is constructed first with an ultraviolet cutoff as a phenomenological ansatz. The cutoff is then removed in an attempt to obtain a more fundamental theory, whereupon the question arises of the covariance and uniqueness of the resulting renormalized energy-momentum tensor. In the case of a massless field in a spatially flat universe, an apparent infrared divergence is discussed from the point of view of operational determination of the renormalized coupling constants. In the other cases, although the divergences are successfully accounted for by renormalization, we are left with finite leading terms which do not appear to be identifiable with geometrical tensors; the significance of this result is under investigation. If these anomalous terms are dropped, the renormalized energy-momentum tensor agrees with that defined by adiabatic regularization, provided that the limit of slow time variation taken in that method is generalized to a limit of “spacetime flatness.”     

Gravitational Casimir Effect at Finite Temperature

The energy-momentum tensor for the gravitoelectromagnetism-(GEM) theory in the real-time finite temperature field theory formalism is presented. Expressions for the Casimir energy and pressure at zero and finite temperature are obtained. An analysis of the Casimir effect for the GEM field is developed.     

Anomalies and Hawking Radiation of NUT-Kerr-Newman de Sitter Black Hole

Hawking radiation of NUT-Kerr-Newman de Sitter black hole is studied via anomalous point of view in this paper. The results show that the charged current and energy-momentum tensor fluxes, to restore gauge invariance and general coordinate covariance at the quantum level in the effective field theory, are exactly equal to those of Hawking radiation from the event horizon (EH) and the cosmological horizon (CH) of NUT-Kerr-Newman de Sitter black hole, respectively.