Moving, Reproducing, and Dying Beyond Flatland: Malthusian Flocks in Dimensions d>2.
Moving, Reproducing, and Dying Beyond Flatland: Malthusian Flocks in Dimensions d>2.
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DOI：
10.1103/physrevlett.125.098003
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发表时间：
2020-01
影响因子：
8.6
通讯作者：
Leiming Chen;Chiu Fan Lee;J. Toner
中科院分区：
文献类型：
--
作者：
Leiming Chen;Chiu Fan Lee;J. Toner
我们证明了“马尔萨斯群体”--即在运动过程中“出生”和“死亡”的自行体(如生物)的一致运动的集合--在空间维度d>；2中属于一个新的普适性类。我们计算了这个新普适性类在ε=4-d展开中为O(ε)的普适指数和标度律，并且发现这些不同于以前被猜想为“不朽的”群(即那些没有出生和死亡的)的“正则”指数，并且被证明在d>；2.我们的展开式在d=3时应该是相当准确的，允许在我们的理论、模拟和实验之间进行精确的定量比较。
We show that "Malthusian flocks"-i.e., coherently moving collections of self-propelled entities (such as living creatures) which are being "born" and "dying" during their motion-belong to a new universality class in spatial dimensions d>2. We calculate the universal exponents and scaling laws of this new universality class to O(ε) in an ε=4-d expansion, and find these are different from the "canonical" exponents previously conjectured to hold for "immortal" flocks (i.e., those without birth and death) and shown to hold for incompressible flocks in d>2. Our expansion should be quite accurate in d=3, allowing precise quantitative comparisons between our theory, simulations, and experiments.