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1.
SO(10)大统一模型有限温度下的有效势的计算,首先应计算Φ4标量场有限温度下的有效势,同时考虑非阿贝尔规范理论的有效势,由此计算出有限温度下的so(10)大统一模型的有效势,这一有效势实际上是零温下的有效势与考虑温度后的修正项之和。  相似文献   

2.
二氯二茂锆络合物的有效势从头计算   总被引:3,自引:1,他引:2  
采用Barthelat有效势价电子从头计算法,对二氯二茂锆络合物的电子结构进行计算,并获得满意的结果。(1)络合物的HOMO能量为-1.6744*10^-18J,主要是由两个氯配位体的pz轨道构成;LUMO的能量为3.2683*10^-20J。主要是由中心金属Zr原子的dxy和dxx轨道构成。(2)电荷分布情况:Zr为1.7821;Cl(1)和Cl(2)均为-.03966,Cp(1)和Cp(2)均  相似文献   

3.
以汤川核力场为例,说明用有效势方法讨论有心力场中圆形轨道的稳定性,数学处理比较简明,物理图象也比较清晰。进而指出非径向微扰引起的速度矩变化对稳定圆轨道半径r_0的影响,导出两者变化的数量关系,说明在汤川核力场中维持稳定圆运动对微扰量所加的限制。  相似文献   

4.
使用最优化微扰论方法计算了夸克介子模型下的有效势。在计算过程中,展开到最优化微扰论参数的一阶,从而明显地包含了普通有效势的双圈图效应,对应于普通有效势中礹的二阶展开。但由于该方法的本质是变分方法,所以更高阶的效应隐含在有效势的表达式中,从而提高了计算的精度。同时,因零温度部分的重整化可能定性地影响相变的性质,因此我们使用改变的最小减除方案对有效势的零温部分进行了重整化。结果表明,通过最优化微扰论方法计算出的有效势,与夸克介子模型下的普通有效势一样都是可重整化的,不会出现新的复杂性。给出的展开到一阶的有效势的解析表达式可以用来进一步研究QCD的相图等物理现象。  相似文献   

5.
一个非Kerr黑洞时空中的Dirac能级分布与黑洞的质量多极矩(用参数an表示)有关,此黑洞的视界面上出现内禀奇性处的Dirac能级有明显的分布特征。  相似文献   

6.
Bc介子质量及波函数   总被引:1,自引:1,他引:0  
利用基于BS方程的有效势模型理论计算束缚态(cb)体系质量谱和波函数,给出了考虑延延效应和略掉延迟效应两种情况下,(cb)体系质量谱和Bc介子波函数。  相似文献   

7.
对近地航天器有显著影响的J2项摄动势函数是轴对称的.而当航天器的轨道倾角为零时,J2项势函数由轴对称退化为球对称.本文从能量的角度来研究近地航天器J2束缚轨道特性.通过引入"势能井"的概念,证明了J2项势函数作用下,赤道平面内存在两类束缚轨道:环形束缚轨道与圆形封闭轨道.根据总能量与有效势的关系,分析了形成这两类J2束缚轨道的条件.利用球对称势的周期性理论,借助椭圆积分推导了环形J2轨道径向周期、周向周期和向径的表达式,以及圆形J2轨道的周期和角速度.分析了圆形封闭轨道的稳定性,以及受到小扰动后向径的演化规律.最后探讨了这两类J2束缚轨道潜在的应用.  相似文献   

8.
对近地航天器有显著影响的J2项摄动势函数是轴对称的.而当航天器的轨道倾角为零时,J2项势函数由轴对称退化为球对称.本文从能量的角度来研究近地航天器J2束缚轨道特性.通过引入"势能井"的概念,证明了J2项势函数作用下,赤道平面内存在两类束缚轨道:环形束缚轨道与圆形封闭轨道.根据总能量与有效势的关系,分析了形成这两类J2束缚轨道的条件.利用球对称势的周期性理论,借助椭圆积分推导了环形J2轨道径向周期、周向周期和向径的表达式,以及圆形J2轨道的周期和角速度.分析了圆形封闭轨道的稳定性,以及受到小扰动后向径的演化规律.最后探讨了这两类J2束缚轨道潜在的应用.  相似文献   

9.
运用半经验分子轨道AM1方法计算了金刚石(111)面上乙炔吸附分子的几何构型,通过与相似结构的丙烯分子实验参数的比较,分析论证了半经验分子轨道方法用于碳氢化合物吸附分子几何构型计算的可靠性.  相似文献   

10.
Reissner—Nordstrom黑洞与面积定理   总被引:1,自引:0,他引:1  
考虑Reissner-Nordstrom(R-N)黑洞的度规场和电磁场张量,研究限落入黑洞的物理粒子。得出结论:任何物理粒子落入R-N黑洞必定使得R-N黑洞的外视界的面积增加或不变,刚好与面积定理相符。  相似文献   

11.
利用黑洞吸积盘演化的基本方程组 ,在纯吸积情况下 ,求得了薄、厚吸积盘及一般厚吸积盘的黑洞视界半径rH的演化方程 .证实了中心黑洞与吸积盘相互影响的基本性质 ,并得到一些新的结果 .黑洞视界半径rH演化并非完全单调 ,其演化特性与吸积盘的类型有关 :对于薄盘 ,rH单调递增 ;对于临界厚盘 ,rH先增后减 ;对于一般厚盘 ,rH先增后减再递增 .还讨论了吸积盘内边缘与黑洞视界间隔的演化 .  相似文献   

12.
相对论天体物理中,由于黑洞附近时空弯曲相当严重,我们可以得到一些在平直时空中难以想象的有趣效应。在克尔旋转黑洞的时空背景中,磁场可以转变为电场,在此基础上,我们将讨论电荷的吸积以及克尔黑洞转变为克尔-纽曼黑洞等问题。  相似文献   

13.
14.
Gallo E  Fender R  Kaiser C  Russell D  Morganti R  Oosterloo T  Heinz S 《Nature》2005,436(7052):819-821
Black holes undergoing accretion are thought to emit the bulk of their power in the X-ray band by releasing the gravitational potential energy of the infalling matter. At the same time, they are capable of producing highly collimated jets of energy and particles flowing out of the system with relativistic velocities. Here we show that the 10-solar-mass (10M(o)) black hole in the X-ray binary Cygnus X-1 (refs 3-5) is surrounded by a large-scale (approximately 5 pc in diameter) ring-like structure that appears to be inflated by the inner radio jet. We estimate that in order to sustain the observed emission of the ring, the jet of Cygnus X-1 has to carry a kinetic power that can be as high as the bolometric X-ray luminosity of the binary system. This result may imply that low-luminosity stellar-mass black holes as a whole dissipate the bulk of the liberated accretion power in the form of 'dark', radiatively inefficient relativistic outflows, rather than locally in the X-ray-emitting inflow.  相似文献   

15.
本文在文献[1]、[2]的基础上,应用相对论性牛顿万有引力定律,对原初典型恒星及其星核M。黑洞的形成、演化和结构,作了更深入的探索研究.得到了一系列很有意义的结果:1、导出了原初典型恒星Mo及其星核Ms黑洞质量的上界和下界.进而导出了原初典型恒星在其简并中子黑涧(Mos=Mo)态下一分为二的死亡大爆炸中释放能量的上下界(即超新星爆发所释放能量的上下界);2、导出了星核Ms黑洞独有的一系列鼎级极限物理特性.导出了黑洞无内阻理想流体的超流效应及黑洞吸集粒子的经纬分流的筛选效应.证明了星核Ms黑洞是具有不再爆炸、不再坍缩、不再发射的“三不”特性的稳定天体;3、在相对论性引力理论框架内,证明了光速最大原理;4、导出了原初典型恒星在一分为二的死亡大爆炸中静质量Mo、场(暗)质量△MG的结构和分布规律.揭示了星核Ms黑洞结构的奥秘;5、导出了恒星、星系、总星系等典型层次天体的真空中场(暗)质量的分布规律.  相似文献   

16.
Active galactic nuclei, which are powered by long-term accretion onto central supermassive black holes, produce relativistic jets with lifetimes of at least one million years, and the observation of the birth of such a jet is therefore unlikely. Transient accretion onto a supermassive black hole, for example through the tidal disruption of a stray star, thus offers a rare opportunity to study the birth of a relativistic jet. On 25 March 2011, an unusual transient source (Swift J164449.3+573451) was found, potentially representing such an accretion event. Here we report observations spanning centimetre to millimetre wavelengths and covering the first month of evolution of a luminous radio transient associated with Swift J164449.3+573451. The radio transient coincides with the nucleus of an inactive galaxy. We conclude that we are seeing a newly formed relativistic outflow, launched by transient accretion onto a million-solar-mass black hole. A relativistic outflow is not predicted in this situation, but we show that the tidal disruption of a star naturally explains the observed high-energy properties and radio luminosity and the inferred rate of such events. The weaker beaming in the radio-frequency spectrum relative to γ-rays or X-rays suggests that radio searches may uncover similar events out to redshifts of z?≈?6.  相似文献   

17.
Shen ZQ  Lo KY  Liang MC  Ho PT  Zhao JH 《Nature》2005,438(7064):62-64
Although it is widely accepted that most galaxies have supermassive black holes at their centres, concrete proof has proved elusive. Sagittarius A* (Sgr A*), an extremely compact radio source at the centre of our Galaxy, is the best candidate for proof, because it is the closest. Previous very-long-baseline interferometry observations (at 7 mm wavelength) reported that Sgr A* is approximately 2 astronomical units (au) in size, but this is still larger than the 'shadow' (a remarkably dim inner region encircled by a bright ring) that should arise from general relativistic effects near the event horizon of the black hole. Moreover, the measured size is wavelength dependent. Here we report a radio image of Sgr A* at a wavelength of 3.5 mm, demonstrating that its size is approximately 1 au. When combined with the lower limit on its mass, the lower limit on the mass density is 6.5 x 10(21)M(o) pc(-3) (where M(o) is the solar mass), which provides strong evidence that Sgr A* is a supermassive black hole. The power-law relationship between wavelength and intrinsic size (size proportional, variantwavelength(1.09)) explicitly rules out explanations other than those emission models with stratified structure, which predict a smaller emitting region observed at a shorter radio wavelength.  相似文献   

18.
Supermassive black holes have powerful gravitational fields with strong gradients that can destroy stars that get too close, producing a bright flare in ultraviolet and X-ray spectral regions from stellar debris that forms an accretion disk around the black hole. The aftermath of this process may have been seen several times over the past two decades in the form of sparsely sampled, slowly fading emission from distant galaxies, but the onset of the stellar disruption event has not hitherto been observed. Here we report observations of a bright X-ray flare from the extragalactic transient Swift J164449.3+573451. This source increased in brightness in the X-ray band by a factor of at least 10,000 since 1990 and by a factor of at least 100 since early 2010. We conclude that we have captured the onset of relativistic jet activity from a supermassive black hole. A companion paper comes to similar conclusions on the basis of radio observations. This event is probably due to the tidal disruption of a star falling into a supermassive black hole, but the detailed behaviour differs from current theoretical models of such events.  相似文献   

19.
从相互耦合的四维引力、单极子作用量和四维无质量标量场作用量出发,利用球对称退化的两维伸缩子理论,通过微扰方法获得了量子修正的Barriola-Vilenkin黑洞解.发现黑洞熵的量子修正要写成klnAh的形式,其中Ak是黑洞的视界面积,而常数k则依赖于量子化方法.  相似文献   

20.
分别研究了用Eddington-Finkelstein时间v和普通时间t描述的二维动态时空中的对称黑洞,得到了局部事件视界、温度和标量场的热谱.用t描述的动态对称黑洞有奇特的结构,它的局部视界个数是对应静态黑洞的2倍,有理由推测最外面的2个局部事件视界之间存在量子能层,因此解析延拓方法不同于稳态黑洞和v描述的动态黑洞.还给出了一个确定广义Tortoise坐标变换的普遍适用的新方法  相似文献   

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