共查询到20条相似文献,搜索用时 78 毫秒
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考虑真空涨落能量为负的特点,提出一个能够简洁描述原子与真空涨落相互作用的方程,得到原子处于激发态的概率随时间变化的关系,讨论了原子自发辐射的速率与真空涨落的强度的关系. 相似文献
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研究了V型三能级原子BEC与双模压缩光场相互作用系统中,忽略原子间相互作用和考虑原子间相互作用时光场的正交压缩和光子数压缩。结果表明,光场的正交压缩依赖于压缩参数,而光子数压缩与压缩参数、光场信号强度有关,在一定条件下,两种压缩可同时存在。原子间相互作用影响两种压缩的涨落随时间变化的周期,以及正交分量涨落随时间变化的幅度,而对光子数压缩涨落随时间变化的幅度几乎无影响。 相似文献
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应用偏振光的量子理论和斯托克斯算符研究了无克尔媒质和存在克尔媒质情况下,光在与原子相互作用过程中偏振态的演化.研究了偏振光中斯托克斯参量的涨落及其压缩的非经典行为.偏振椭圆、量子光学中的偏振度和斯托克斯参量的信噪比也得到了讨论.结果表明斯托克斯参量及其涨落在时间演化中呈现出被调制的振荡,这些振荡表现出间歇地崩塌和恢复.在与原子的相互作用过程中,光的偏振椭圆不随时间变化,但偏振度却随时间出现振荡.克尔媒质对这些振荡演化有很大影响.
关键词:
斯托克斯算符
斯托克斯参量
量子偏振态
量子涨落 相似文献
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用理论和模拟相结合的方法研究了Pt(110)面上CO催化氧化体系中由化学反应随机性所导致的内涨落和参量扰动带来的外涨落对其速率振荡过程的影响,重点考察了内涨落和外涨落的相互作用.在体系的确定性Hopf分岔点附近区域,噪声可以诱导产生随机振荡,其信噪比随噪声强度的变化会出现极大值,即发生了相干共振.运用随机范式理论,研究发现体系的相干共振行为依赖于一\有效噪声",其强度是内涨落和外涨落的加权和.研究结果表明,在内外噪声强度的参数平面内,随机振荡的信噪比呈现屋脊形,太大的内涨落或外涨落条件下相干共振都不能发生.数值模拟的结果和理论分析符合得很好. 相似文献
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In this paper,we investigate the agegraphic dark energy(ADE) model by including the sign-changeable interaction between ADE and dark matter in non-flat universe.The interaction Q can change its sign from Q 0 to Q 0 as the universe expands.This indicates that at first dark matter decays to ADE,and then ADE decays to dark matter.We study the dynamical behavior of the model by using the phase-plane analysis.It is shown numerically that the coupling constant β plays an important role in the evolution of the universe.The equation of state(Eo S) of ADE with the sign-changeable interaction is more likely to cross the phantom divide w_d =-1 from top to bottom with the increasing of the |β|.Whereas in ADE model with usual interaction,wd can cross the phantom divide from bottom to top.We also find that our model is consistent with the observational data. 相似文献
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We assume generalized ghost Pilgrim dark energy (GGPDE) model in the presence of cold dark matter in flat FRW universe. With suitable choice of interaction term between GGPDE and cold dark matter, we investigate the nature of equation of state parameter for GGPDE. Also, we investigate the natures of dynamical scalar field models (such as quintessence, tachyon, k-essence, and dilaton dark energy) and concerned potentials through the correspondence phenomenon between GGPDE and these models. 相似文献
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The holographic dark energy (HDE) is now an interesting candidate of dark energy, which has been studied extensively in the literature. In the derivation of HDE, the black hole entropy plays an important role. In fact, the entropy-area relation can be modified due to loop quantum gravity or other reasons. With the modified entropy-area relation, we propose the so-called ``entropy-corrected holographic dark energy' (ECHDE) in the present work. We consider many aspects of ECHDE and find some interesting results. In addition, we briefly consider the so-called ``entropy-corrected agegraphic dark energy' (ECADE). 相似文献
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In this paper, we investigate the new agegraphic dark energy model in the framework of Brans-Dicke theory, which is a natural extension of the Einstein's general relativity. In this framework the form of the new agegraphic dark energy density takes as ρq =3n2 φ(t) η-2, where η is the conformalage of the universe and φ(t) is the Brans-Dicke scalar field representing the inverse of the time-variable Newton's constant. We derive the equation of state of the new agegraphic dark energy and the deceleration parameter of the universe in the Brans-Dicke theory. It is very interesting to find that in the Brans-Dicke theory the agegraphic dark energy realizes quintom-like behavior,i.e., its equation of state crosses the phantom divide w=-1 duringthe evolution. We also compare the situation of the agegraphic darkenergy model in the Brans-Dicke theory with that in the Einstein'stheory. In addition, we discuss the new agegraphic dark energy modelwith interaction in the framework of the Brans-Dicke theory. 相似文献
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暗孤子的周期性再生效应 总被引:1,自引:0,他引:1
通过数值求解变系数非线性薛定谔方程,讨论具有有限背景宽度的皮秒暗光脉冲的传输和相互作用。结果表明,一种新的效应,即暗孤子的周期性再生效应,稳定地存在于具有分布参量的光纤系统中,不会受到孤子间相互作用的影响。并且,这种再生效应对损耗和有限的扰动(如白噪声)等不敏感。这表明暗孤子的周期性再生效应是稳定的。 相似文献
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LI Miao LI Xiao-Dong LIN Chun-Shan WANG Yi 《理论物理通讯》2009,51(1):181-186
We investigate the statistical nature of holographic gas, which may represent the quasi-particle excitations of a strongly correlated gravitational system. We find that the holographic entropy can be obtained by modifying degeneracy. We calculate thermodynamical quantities and investigate stability of the holographic gas. When applying to cosmology, we find that the holographic gas behaves as holographic dark energy, and the parameter c in holographic dark energy can be calculated from our model. Our model of holographic gas generally predicts c 〈 1, implying that the fate of our universe is phantom-like. 相似文献
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The objective of this paper is to discuss the Chameleon Brans–Dicke gravity with non-minimally matter coupling of scalar field. We take modified Holographic Ricci dark energy model in this gravity with its energy density in interaction with energy density of cold dark matter. We assume power-law ansatz for scale factor and scalar field to discuss potential as well as coupling functions in the evolving universe. These reconstructed functions are plotted versus scalar field and time for different values of power component of scale factor n. We observe that potential and coupling functions represent increasing behavior, in particular, consistent results for a specific value of n. Finally, we have examined validity of the generalized second law of thermodynamics and we have observed its validity for all values of n. 相似文献
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A cosmological model of dark energy interacting with dark matter and another general component of the universe is considered. The equations for the coincidence parameters r and s, which represent the ratios between dark energy and dark matter and the other cosmic fluid respectively, are analyzed in terms of the stability of stationary solutions. The obtained general results allow to shed some light on the equations of state of the three interacting fluids, due to the constraints imposed by the stability of the solutions. We found that for an interaction proportional to the sum of the dark energy density and the third fluid density, the hypothetical fluid must have positive pressure, which leads naturally to a cosmological scenario with radiation, unparticle or even some form of warm dark matter as the third interacting fluid. 相似文献
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飞秒暗孤子间相互作用的数值研究 总被引:7,自引:1,他引:6
通过数值模拟对飞秒暗孤子间的相互作用进行了研究,并且同飞秒亮孤子和皮秒暗孤子分别进行了比较,结果表明:同飞秒亮孤子相比,飞秒暗孤子间的相互作用比较小,前者表现为相互吸引、碰撞、合二为一,然后相互排斥,不具有周期性;而后者从一开始就相互排斥,且这种排斥作用较亮孤子来说相当微弱,同样也不具有周期性。此外,数值模拟的结果还表明,飞秒暗孤子间的相互作用同皮秒尺度下暗孤子间的相互作用基本一致,并且通过计算表明,飞秒暗孤子间的相互作用在一定范围内仍可利用皮秒尺度下暗孤子间相互作用的经验公式。但是,数值模拟结果显示,两孤子的初始间距越小,由经验公式计算结果所带来的误差就越大。 相似文献
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文章首先对暗物质的概念作了简单介绍,接着介绍了暗物质的发现过程和暗物质存在的证据等.随后,介绍了目前人们对暗物质粒子基本性质的理解和目前比较流行的暗物质模型,并解释了弱相互作用重粒子(WIMP)为什么获得人们最多的关注.文中还简单介绍了目前探测暗物质粒子的三种实验方法:对撞机探测法、直接探测法和间接探测法.最后,介绍了目前暗物质探测的最新进展,包括来自DAMA,CoGent,PAMELA,ATIC,Fermi等实验的最新结果. 相似文献