共查询到18条相似文献,搜索用时 125 毫秒
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基于动力学重整化群理论研究表面界面生长动力学标度奇异性问题, 得到含时空关联噪声的表面生长方程标度奇异指数的一般结果,并将此方法应用于几种典型的局域生长方程——Kardar-Parisi-Zhang(KPZ)方程、线性生长方程、Lai-Das Sarma-Villain(LDV)方程.结果表明,在长波长极限下局域生长方程的动力学标度奇异性与最相关项、基底维数以及噪声有关,并且若出现标度奇异性,只会是超粗化(super rough)奇异标度行为,而不是内禀(intrinsically)奇异标度行为.
关键词:
标度奇异性
动力学重整化群理论
时空关联噪声 相似文献
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利用Yamada微扰论结合重整微扰方法来计算非对称Anderson模型,得到了局域电子占据数、重整化因子、重整化的局域能级以及重整化参数关于裸参数的展开式.计算了局域电子态密度和低温杂质电导,还计算了磁场对它们的影响,这些结果适用于从弱耦合到强耦合的整个耦合强度区域.由于在哈密顿量中已经将局域能级进行了初步重整,采用的重整微扰方法比Hewson的重整微扰方法更适合于研究非对称Anderson模型.
关键词:
非对称Anderson模型
重整化
磁场 相似文献
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利用直接标度分析方法研究一个含有广义守恒律生长方程的标度奇异性,得到强弱耦合区域的奇异标度指数.作为其特殊情况,这个方程包含Kardar-Parisi-Zhang(KPZ)方程、 Sun-Guo-Grant(SGG)方程以及分子束外延(MBE)生长方程,并能对其进行统一的研究.研究发现, KPZ方程和SGG方程,无论在弱耦合还是在强耦合区域内都遵从自仿射Family -Vicsek正常标度规律;而MBE 方程在弱耦合区域内服从正常标度,在强耦合区域内能呈现内禀奇异标度行为.这里所得到生长方程的奇异标度性质与利用重正化群理论、数值模拟以及实验相符很好.
关键词:
标度奇异性
强耦合
弱耦合 相似文献
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本文讨论了禁闭弱作用亚夸克大统一模型. 在合理的统一能标和禁闭标度条件下, 利用重整化群方法得到超色规范群SU(n)满足n≤3, 大统一规范群是SU(7). SU(8)和SO(14). 相似文献
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Chattopadhyay AK 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,60(1):293-296
The effects of spatially correlated noise on a phenomenological equation equivalent to a nonlocal version of the Kardar-Parisi-Zhang (KPZ) equation are studied via the dynamic renormalization group (DRG) techniques. The correlated noise coupled with the long ranged nature of interactions prove the existence of different phases in different regimes, giving rise to a range of roughness exponents defined by their corresponding critical dimensions. Finally self-consistent mode analysis is employed to compare the non-KPZ exponents obtained as a result of the long-range interactions with the DRG results. 相似文献
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L. Zhang G. Tang Z. Xun K. Han H. Chen B. Hu 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,63(2):227-234
The long-wavelength properties of the (d + 1)-dimensional
Kuramoto-Sivashinsky (KS) equation with both conservative and nonconservative
noises are investigated by use of the dynamic renormalization-group (DRG)
theory. The dynamic exponent z and roughness exponent α are
calculated for substrate dimensions d = 1 and d = 2, respectively. In the
case of d = 1, we arrive at the critical exponents z = 1.5 and α = 0.5
, which are consistent with the results obtained by Ueno et al. in the
discussion of the same noisy KS equation in 1+1 dimensions [Phys. Rev. E 71,
046138 (2005)] and are believed to be identical with the dynamic scaling of
the Kardar-Parisi-Zhang (KPZ) in 1+1 dimensions. In the case of d = 2, we
find a fixed point with the dynamic exponents z = 2.866 and α = -0.866
, which show that, as in the 1 + 1 dimensions situation, the existence of
the conservative noise in 2 + 1 or higher dimensional KS equation can also
lead to new fixed points with different dynamic scaling exponents. In
addition, since a higher order approximation is adopted, our calculations in
this paper have improved the results obtained previously by Cuerno and
Lauritsen [Phys. Rev. E 52, 4853 (1995)] in the DRG analysis of the noisy KS
equation, where the conservative noise is not taken into account. 相似文献
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The anomalous dynamic scaling behavior of the d+1 dimensional non-local growth equations is investigated based on the scaling approach. The growth equations studied include the non-local Kardar-Parisi-Zhang (NKPZ), non-local Sun-Guo-Grant (NSGG), and non-local Lai-Das Sarma-Villain (NLDV) equations. The anomalous scaling exponents in both the weak- and strong-coupling regions are obtained, respectively. Our results show that non-local interactions can affect anomalous scaling properties of surface fluctuations. 相似文献
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In this paper, a mode of using the Dynamic Renormalization Group (DRG) method is suggested in order to cope with inconsistent results obtained when applying it to a continuous family of one-dimensional nonlocal models. The key observation is that the correct fixed-point dynamical system has to be identified during the analysis in order to account for all the relevant terms that are generated under renormalization. This is well established for static problems, however poorly implemented in dynamical ones. An application of this approach to a nonlocal extension of the Kardar–Parisi–Zhang equation resolves certain problems in one-dimension. Namely, obviously problematic predictions are eliminated and the existing exact analytic results are recovered. 相似文献
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Intermittency is a basic feature of fully developed turbulence, for both velocity and passive scalars.
Intermittency is classically characterized by
Eulerian scaling exponent of structure functions. The same approach can
be used in a Lagrangian framework to characterize the temporal
intermittency of the velocity and passive scalar concentration of a an element of fluid advected by a turbulent intermittent
field. Here we focus on
Lagrangian passive scalar scaling exponents, and discuss their possible links
with Eulerian passive scalar and mixed velocity-passive scalar structure functions.
We provide different transformations between these scaling exponents,
associated to different transformations linking space and time scales.
We obtain four new explicit relations.
Experimental data are needed to test these predictions for Lagrangian passive
scalar scaling exponents. 相似文献
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We propose a new approach to the old-standing problem of the anomaly of the scaling exponents of nonlinear models of turbulence. We construct, for any given nonlinear model, a linear model of passive advection of an auxiliary field whose anomalous scaling exponents are the same as the scaling exponents of the nonlinear problem. The statistics of the auxiliary linear model are dominated by "statistically preserved structures" which are associated with exact conservation laws. The latter can be used, for example, to determine the value of the anomalous scaling exponent of the second order structure function. The approach is equally applicable to shell models and to the Navier-Stokes equations. 相似文献
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The scaling of the amplitude and time distributions of acoustic emission pulses, which reflects the self-similarity of defect structures, is revealed. The possibility of separation of independent contributions to the flow of acoustic emission events, which have substantially different scaling exponents, is shown for porous materials. The differences in the scaling exponents are related to the development of plastic deformation and fracture of the materials. The developed approach to an analysis of acoustic emission can be used to describe its predominant mechanisms during deformation. 相似文献
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We investigate numerically the chaotic sea of the complete Fermi-Ulam model (FUM) and of its simplified version (SFUM). We perform a scaling analysis near the integrable to non-integrable transition to describe the average energy as function of time t and as function of iteration (or collision) number n. When t is employed as independent variable, the exponents of FUM and SFUM are different. However, when n is used, the exponents are the same for both FUM and SFUM. In the collision number analysis, we present analytical arguments supporting the values of the exponents related to the control paramenter and to the initial velocity. We describe also how the scaling exponents obtained by using t as independent variable are related to the ones obtained with n. In contrast to SFUM, the average energy in FUM saturates for long times. We discuss the origin of the observed differences and similarities between FUM and its simplified version. 相似文献