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| | 混沌最早出现在''N''=4的情况下。在某些<math>\omega_1, \omega_2, \omega_3, K</math>的设置下,系统存在[[奇异吸引子]]<ref>{{Cite journal |last1=Maistrenko |first1=Yuri L. |last2=Popovych |first2=Oleksandr V. |last3=Tass |first3=Peter A. |title=Kuramoto模型的混沌吸引子 |date=November 2005 |url=https://www.worldscientific.com/doi/abs/10.1142/S0218127405014155 |journal=国际双困杂志 |language=en |volume=15 |issue=11 |pages=3457–3466 |doi=10.1142/S0218127405014155 |bibcode=2005IJBC...15.3457M |issn=0218-1274}}</ref>。 | | 混沌最早出现在''N''=4的情况下。在某些<math>\omega_1, \omega_2, \omega_3, K</math>的设置下,系统存在[[奇异吸引子]]<ref>{{Cite journal |last1=Maistrenko |first1=Yuri L. |last2=Popovych |first2=Oleksandr V. |last3=Tass |first3=Peter A. |title=Kuramoto模型的混沌吸引子 |date=November 2005 |url=https://www.worldscientific.com/doi/abs/10.1142/S0218127405014155 |journal=国际双困杂志 |language=en |volume=15 |issue=11 |pages=3457–3466 |doi=10.1142/S0218127405014155 |bibcode=2005IJBC...15.3457M |issn=0218-1274}}</ref>。 |
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| − | == Connection to Hamiltonian systems == | + | == 与哈密顿系统的联系 == |
| − | The dissipative Kuramoto model is contained<ref>{{cite journal | last1 = Witthaut | first1 = Dirk | last2 = Timme | first2 = Marc | title = Kuramoto Dynamics in Hamiltonian Systems | journal = Phys. Rev. E | volume=90 | issue = 3 | pages = 032917 | doi = 10.1103/PhysRevE.90.032917| pmid = 25314514 | year = 2014|arxiv = 1305.1742 |bibcode = 2014PhRvE..90c2917W | s2cid = 7510614 }}</ref> in certain conservative [[Hamiltonian mechanics|Hamiltonian systems]] with [[Hamilton function|Hamiltonian]] of the form
| + | 耗散型库拉莫托模型包含在某些具有以下形式的[[哈密顿函数]]的[[保守哈密顿系统]]中:<ref>{{cite journal | last1 = Witthaut | first1 = Dirk | last2 = Timme | first2 = Marc | title = 哈密顿系统中的库拉莫托动力学 | journal = 物理评论E | volume=90 | issue = 3 | pages = 032917 | doi = 10.1103/PhysRevE.90.032917| pmid = 25314514 | year = 2014|arxiv = 1305.1742 |bibcode = 2014PhRvE..90c2917W | s2cid = 7510614 }}</ref> |
| − | :<math> \mathcal{H}(q_1,\ldots, q_N, p_1, \ldots, p_N) = \sum_{i = 1}^N \frac{\omega_i}{2} (q_i^2 + p_i^2) + \frac{K}{4N} \sum_{i,j = 1}^{N} | + | :<math> \mathcal{H}(q_1,\ldots, q_N, p_1, \ldots, p_N) = \sum_{i = 1}^N \frac{\omega_i}{2} (q_i^2 + p_i^2) + \frac{K}{4N} \sum_{i,j = 1}^{N} (q_i p_j - q_j p_i) ( q_j^2 + p_j^2 - q_i^2 - p_i^2 ) </math> |
| − | (q_i p_j - q_j p_i) ( q_j^2 + p_j^2 - q_i^2 - p_i^2 ) </math>
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| − | After a canonical transformation to action-angle variables with actions <math> I_i = \left( q_i^2 + p_i^2 \right)/2 </math> and angles (phases) <math>
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| − | \phi_i = \mathrm{arctan} \left( q_i/p_i \right) </math>, exact Kuramoto dynamics emerges on invariant manifolds of constant <math> I_i \equiv I </math>. With the transformed Hamiltonian
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| − | :<math> \mathcal{H'}(I_1, \ldots I_N, \phi_1 \ldots, \phi_N) = \sum_{i = 1}^N \omega_i I_i
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| − | - \frac{K}{N} \sum_{i = 1}^{N} \sum_{j = 1}^{N}
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| − | \sqrt{I_j I_i} (I_j - I_i) \sin(\phi_j - \phi_i), </math>
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| − | Hamilton's equation of motion become
| + | 在将正则变换应用于作用-角度变量(以作用<math> I_i = \left( q_i^2 + p_i^2 \right)/2 </math>和角度(相位)<math> \phi_i = \mathrm{arctan} \left( q_i/p_i \right) </math>为变量)后,库拉莫托动力学在常数<math> I_i \equiv I </math>的不变流形上出现。经过变换的哈密顿函数为: |
| − | :<math> | + | :<math> \mathcal{H'}(I_1, \ldots I_N, \phi_1 \ldots, \phi_N) = \sum_{i = 1}^N \omega_i I_i - \frac{K}{N} \sum_{i = 1}^{N} \sum_{j = 1}^{N} \sqrt{I_j I_i} (I_j - I_i) \sin(\phi_j - \phi_i), </math> |
| − | \frac{d I_i}{dt} = - \frac{\partial \mathcal{H}'}{\partial \phi_i}
| + | |
| − | = - \frac{2 K}{N} \sum_{k=1}^N \sqrt{I_k I_i} (I_k - I_i) \cos(\phi_k - \phi_i)
| + | 哈密顿运动方程变为: |
| − | </math> | + | :<math> \frac{d I_i}{dt} = - \frac{\partial \mathcal{H}'}{\partial \phi_i} = - \frac{2 K}{N} \sum_{k=1}^N \sqrt{I_k I_i} (I_k - I_i) \cos(\phi_k - \phi_i) </math> |
| − | and
| + | 和 |
| − | :<math> | + | :<math> \frac{d \phi_i}{dt} = \frac{\partial \mathcal{H}'}{\partial I_i} = \omega_i + \frac{K}{N} \sum_{k=1}^N \left[ 2 \sqrt{I_i I_k} \sin(\phi_k - \phi_i) \right. \left. + \sqrt{I_k/I_i} (I_k - I_i) \sin(\phi_k - \phi_i) \right] . </math> |
| − | \frac{d \phi_i}{dt} = \frac{\partial \mathcal{H}'}{\partial I_i}
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| − | = \omega_i + \frac{K}{N}
| + | 因此,当<math> I_j = I </math>时,流形是守恒的,因为<math> \frac{d I_i}{dt} = 0 </math>,而相位动力学<math> \frac{d \phi_i}{dt} </math>成为库拉莫托模型的动力学(当<math> I = 1/2 </math>时,耦合常数相同)。这一类哈密顿系统包括某些量子-经典系统,例如[[玻色-爱因斯坦凝聚态]]。 |
| − | \sum_{k=1}^N \left[ 2 \sqrt{I_i I_k} \sin(\phi_k - \phi_i) \right. | |
| − | \left. +
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| − | \sqrt{I_k/I_i} (I_k - I_i) \sin(\phi_k - \phi_i) \right] .
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| − | </math> | |
| − | So the manifold with <math> I_j = I </math> is invariant because <math> \frac{d I_i}{dt} = 0 </math> and the phase dynamics <math> \frac{d \phi_i}{dt} </math> becomes the dynamics of the Kuramoto model (with the same coupling constants for <math> I = 1/2 </math>). The class of Hamiltonian systems characterizes certain quantum-classical systems including [[Bose–Einstein condensate]]s.
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| | == Variations of the models == | | == Variations of the models == |