Deformed random walk: Suppression of randomness and inhomogeneous diffusion

被引:4
|
作者
Gomez, Ignacio S. [1 ]
机构
[1] Univ Estadual Sudoeste Bahia, Dept Ciencias Exatas & Nat, Rodovia BR 415,Km 03 S-N, BR-45700000 Itapetinga, BA, Brazil
关键词
STATISTICAL-MECHANICS; ALGEBRA;
D O I
10.1103/PhysRevE.107.034113
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
We study a generalization of the random walk (RW) based on a deformed translation of the unitary step, inherited by the q algebra, a mathematical structure underlying nonextensive statistics. The RW with deformed step implies an associated deformed random walk (DRW) provided with a deformed Pascal triangle along with an inhomogeneous diffusion. The paths of the RW in deformed space are divergent, while those corresponding to the DRW converge to a fixed point. Standard random walk is recovered for q -> 1 and a suppression of randomness is manifested for the DRW with -1 < gamma q < 1 and gamma q = 1 - q. The passage to the continuum of the master equation associated to the DRW led to a van Kampen inhomogeneous diffusion equation when the mobility and the temperature are proportional to 1 + gamma qx, and provided with an exponential hyperdiffusion that exhibits a localization of the particle at x = -1/gamma q consistent with the fixed point of the DRW. Complementarily, a comparison with the Plastino-Plastino Fokker-Planck equation is discussed. The two-dimensional case is also studied, by obtaining a 2D deformed random walk and its associated deformed 2D Fokker-Planck equation, which give place to a convergence of the 2D paths for -1 < gamma q1, gamma q2 < 1 and a diffusion with inhomogeneities controlled by two deformation parameters gamma q1 , gamma q2 in the directions x and y. In both the one-dimensional and the two-dimensional cases, the transformation gamma q -> -gamma q implies a change of sign of the corresponding limits of the random walk paths, as a property of the deformation employed.
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页数:9
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