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本文给出了磁场中的Kerr-Newman-Kasuya黑洞(旋转双荷黑洞)的电磁场的严格表式。在Φ《Q=-2B0J的特殊情况下,给出了慢速转动的Kerr-Newman-Kasuya黑洞的引力场表式。
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磁熵变(△SM)与磁场(μ0H)的相关性已在很多二级相变材料中被研究并报道,但一级相变材料的磁热效应与磁场相关性还少有报道.本文在具有一级磁结构相变的Mn0.6Fe0.4NiSi0.5Ge0.5材料中研究发现△SM与μ0H存在线性相关性,并通过麦克斯韦关系式的数值分析详细讨论了这一线性相关性的来源.同时,进一步发现在低磁场时,△SM近似正比于μ0H的平方.该线性相关性同样在一级磁结构相变Ni50Mn34Co2Sn14材料中得到了印证.但由于一级磁弹相变LaFe11.7Si1.3材料相变温度具有更强的磁场依赖性,不具有△SM的线性相关性,因此,本研究表明,当磁结构相变材料的相变温度具有弱磁场依赖性时,△SM与μ0H具有线性相关性.进而,在磁场未达到相变饱和磁场以下,利用△SM与μ0H的线性相关性可以有效推测更高磁场下的△SM. 相似文献
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本文报道了当外磁场He较低时(He<4Hrm,其中Hrm是超导管的最大捕获磁场),超导管的内磁场Hi与时间及外磁场的关系可表示为H0+B0(lnt+1-exp(-t/τ)),式中B0Int与磁通蠕动有关,Bc(1-exp(-t/τ))与外磁场引起的磁通扰动有关。扰动随时间很快衰减.H0,B0及1/τ随外磁场增加,在He>Hrm时,这几个量增加较大。当直流外磁场He<1/2Hrm时,超导管可将其完全屏蔽,对交流场不能完全屏蔽,但其屏蔽效果仍优于最好的金属屏蔽筒。
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采用后牛顿近似方法分析讨论了荷电天体引力场(即Reissner-Nordstr(o)m度规场)中试验粒子的轨道进动情况,给出了荷电量Q对试验粒子轨道进动的影响. 相似文献
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通过引入二重复对称度规张量,建立了一种二重复对称引力理论. 从一个二重实的作用量出发,导出了静态球对称二重复度规的具体表达式. 该理论扩展了Moffat结果,不仅自然地得到了双曲复对称引力理 论,而且把著名的Schwarzschild解作为特殊情况包含在其中,并且在线性化的弱场近似下自动摆脱了Moffat理论中存在的负 能鬼态问题. 进一步,通过将二重复坐标推广到满足二重非对易关系以及将Moyal星积二重 化,由此构造出二重非交换复对称引力场作用量.
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非交换几何
复对称度规
非对易坐标
引力场作用量 相似文献
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采用考虑粒子温度各向异性热等离子体介电张量模型,借助磁化、均匀密度分布等离子体中电磁波的一般色散关系,在低磁场、低气压螺旋波等离子体典型参量条件下,理论分析了电子温度各向异性对电磁模式传播特性和角向对称模功率沉积的影响.研究结果表明:对于给定的纵向静磁场B0(或波频率ω),存在一个临界波频率ωcr(或纵向静磁场B0,cr),当ω>ωcr(或B00,cr)时,电子回旋谐波遭受的阻尼开始显著增大;相比粒子温度各向同性情形,粒子温度各向异性彻底改变了波的传播特性,即相位常数和衰减常数均出现峰值现象;在考虑电子有限拉莫尔半径效应和电子温度各向异性情形下,Trivelpiece-Gould (TG)波碰撞阻尼在整个电磁波功率沉积中占据主导地位,电子纵向温度Te,//存在某一临界值,在此临界值处TG波功率沉积出现峰值Pabs,TG,且随着Te,⊥/Te,//的减小,... 相似文献
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E. Sánchez-Velasco 《Physics letters. [Part B]》1981,105(1):41-42
The influence of the trace anomaly of the energy-momentum tensor of gauge theories is discussed in a spherically symmetric space-time. It is found that for pure electric and magnetic fields, the point β(g) = ?g represents a phase transition from any asymptotically flat metric to an asymptotically non-flat metric which turns out to be confining in the electric case. 相似文献
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Motivated by problems related to quasi-local mass in general relativity, we study the static metric extension conjecture proposed by R. Bartnik [4]. We show that, for any metric on ¯B
1 that is close enough to the Euclidean metric and has reflection invariant boundary data, there always exists an asymptotically flat and scalar flat static metric extension in M=3B
1 such that it satisfies Bartnik's geometric boundary condition [4] on B
1. 相似文献
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The Positive Action conjecture requires that the action of any asymptotically Euclidean 4-dimensional Riemannian metric be positive, vanishing if and only if the space is flat. Because any Ricci flat, asymptotically Euclidean metric has zero action and is local extremum of the action which is a local minimum at flat space, the conjecture requires that there are no Ricci flat asymptotically Euclidean metrics other than flat space, which would establish that flat space is the only local minimum. We prove this for metrics onR
4 and a large class of more complicated topologies and for self-dual metrics. We show that ifR
0 there are no bound states of the Dirac equation and discuss the relevance to possible baryon non-conserving processes mediated by gravitational instantons. We conclude that these are forbidden in the lowest stationary phase approximation. We give a detailed discussion of instantons invariant under anSU(2) orSO(3) isometry group. We find all regular solutions, none of which is asymptotically Euclidean and all of which possess a further Killing vector. In an appendix we construct an approximate self-dual metric onK3 — the only simply connected compact manifold which admits a self-dual metric. 相似文献
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《Physics letters. A》1988,128(5):245-250
We present a new exact solution of the Poincaré gauge theory, namely a charged Kerr-NUT metric with an effective cosmological constant which is consistently coupled to a dynamic torsion field. The solution is given in terms of an orthonormal basis in Boyer-Lindquist coordinates and depends on the constants m0 (mass), j0 (angular momentum), q0 (electric charge), and n0 (NUT parameter). Whereas m0,j0, and q0 can be specified arbitrarily, the NUT parameter and the effective cosmological constant are determined by the coupling constants of our model. The torsion of the solution is centered around the coordinate origin and vanishes asymptotically for large radial distance. For n0=0, we find the exterior gravitational field of a charged spinning source. 相似文献
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本文就声子散射与电离杂质散射的两种散射机构探讨了半导体n型锗的横向磁阻。在简并强磁场情况下,得出声子散射机构在〈111〉,〈110〉和〈100〉三个方向上锗的横向磁阻的表示式。磁阻的平均值的相对大小(ρt<111>)/ρ0:(ρt<110>)/ρ0:(ρt<100>)/ρ0=1:1.7:1.1,并且磁阻具有振荡形式。在非简并量子极限情况下分别对声子散射和杂质散射得出锗的横向磁 相似文献
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It is proved that if a metric space is subjected to a mixing transformation, then there exists a positive numberx
0 such that the probability that any arbitrary set of positive measure is asymptotically mapped into a set of diameter less thanx
0 is zero. Physical implications of this result, in particular the interpretation of Poincaré recurrence, are discussed. 相似文献