×

\(q\)-Gaussians in the porous-medium equation: stability and time evolution. (English) Zbl 1188.82064

Summary: The stability of \(q\)-Gaussian distributions as particular solutions of the linear diffusion equation and its generalized nonlinear form, \(\frac{\partial P(x,t)}{\partial t}=D\frac{\partial^2[P(x,t)]^{2-q}}{\partial x^2}\), the porous-medium equation, is investigated through both numerical and analytical approaches. An analysis of the kurtosis of the distributions strongly suggests that an initial \(q\)-Gaussian, characterized by an index \(q_i\), approaches asymptotically the final, analytic solution of the porous-medium equation, characterized by an index \(q\), in such a way that the relaxation rule for the kurtosis evolves in time according to a \(q\)-exponential, with a relaxation index \(q_{\mathrm{rel}}\equiv q_{\mathrm{rel}}(q)\). In some cases, particularly when one attempts to transform an infinite-variance distribution \((q_i\geq 5/3)\) into a finite-variance one \((q<5/3)\), the relaxation towards the asymptotic solution may occur very slowly in time. This fact might shed some light on the slow relaxation, for some long-range-interacting many-body Hamiltonian systems, from long-standing quasi-stationary states to the ultimate thermal equilibrium state.

MSC:

82C70 Transport processes in time-dependent statistical mechanics
76S05 Flows in porous media; filtration; seepage
82C05 Classical dynamic and nonequilibrium statistical mechanics (general)

References:

[1] N.G. Van Kampen, Stochastic Processes in Physics, Chemistry (North-Holland, Amsterdam, 1981) · Zbl 0511.60038
[2] H. Risken, The Fokker-Planck Equation: Methods of Solution and Applications (Springer- Verlag, Berlin, 1989) · Zbl 0665.60084
[3] T.M. Cover, J.A. Thomas, Elements of Information Theory (Wiley, New York, 1991) · Zbl 0762.94001
[4] M. Muskat, The Flow of Homogeneous Fluids Through Porous Media (McGraw Hill, New York, 1937) · JFM 63.1368.03
[5] E. Lutz, Phys. Rev. A 67, 051402(R) (2003)
[6] P. Douglas, S. Bergamini, F. Renzoni, Phys. Rev. Lett. 96, 110601 (2006)
[7] B. Liu, J. Goree, Phys. Rev. Lett. 100, 055003 (2008)
[8] A. Upaddhyaya, J. Rieu, J. Glazier, Y. Sawada, Physica A 293, 459 (2001)
[9] K.E. Daniels, C. Beck, E. Bodenschatz, Physica D 193, 208 (2004)
[10] T.D. Frank, Nonlinear Fokker-Planck Equations: Fundamentals and Applications (Springer, Berlin, 2005) · Zbl 1071.82001
[11] A.R. Plastino, A. Plastino, Physica A 222, 347 (1995) · Zbl 1020.82502
[12] C. Tsallis, D.J. Bukman, Phys. Rev. E 54, R2197 (1996)
[13] L. Borland, Phys. Rev. E 57, 6634 (1998)
[14] T.D. Frank, A. Daffertshofer, Physica A 272, 497 (1999)
[15] P.H. Chavanis, Eur. Phys. J. B 62, 179 (2008)
[16] E.M.F. Curado, F.D. Nobre, Phys. Rev. E 67, 021107 (2003)
[17] F.D. Nobre, E.M.F. Curado, G. Rowlands, Physica A 334, 109 (2004)
[18] V. Schwämmle, F.D. Nobre, E.M.F. Curado, Phys. Rev. E 76, 041123 (2007)
[19] M. Shiino, Phys. Rev. A 36, 2393 (1987)
[20] V. Schwämmle, E.M.F. Curado, F.D. Nobre, Eur. Phys. J. B 58, 159 (2007)
[21] M. Shiino, J. Math. Phys. 42, 2540 (2001)
[22] T.D. Frank, A. Daffertshofer, Physica A 295, 455 (2001)
[23] T.D. Frank, Physica A 310, 397 (2002)
[24] G. Kaniadakis, Phys. Lett. A 288, 283 (2001)
[25] P.H. Chavanis, Phys. Rev. E 68, 036108 (2003)
[26] Nonextensive Entropy-Interdisciplinary Applications edited by M. Gell-Mann, C. Tsallis (New York, Oxford University Press, 2004)
[27] Nonextensive Statistical Mechanics: New Trends, New Perspectives edited by J.P. Boon, C. Tsallis, Europhys. News 36 (2005); Nonextensive Statistical Mechanics: New Trends, New Perspectives edited by J.P. Boon, C. Tsallis, Europhys. News Vol. 37, 25 (2006)
[28] C. Tsallis, J. Stat. Phys. 52, 479 (1988)
[29] J.L. Vázquez, The Porous Medium Equation. Mathematical Theory (Oxford University Press, Oxford, 2006)
[30] V. Latora, A. Rapisarda, S. Ruffo, Phys. Rev. Lett. 80, 692 (1998)
[31] C. Anteneodo, C. Tsallis, Phys. Rev. Lett. 80, 5313 (1998)
[32] L.G. Moyano, C. Anteneodo, Phys. Rev. E 74, 021118 (2006)
[33] A. Pluchino, A. Rapisarda, C. Tsallis, Europhys. Lett. 80, 26002 (2007)
[34] A. Pluchino, A. Rapisarda, C. Tsallis, Physica A 387, 3121 (2008)
[35] F.D. Nobre, C. Tsallis, Phys. Rev. E 68, 036115 (2003)
[36] F.D. Nobre, C. Tsallis, Physica A 344, 587 (2004)
[37] A. Antoniazzi, D. Fanelli, S. Ruffo, Y.Y. Yamaguchi, Phys. Rev. Lett. 99, 040601 (2007)
[38] A. Antoniazzi, F. Califano, D. Fanelli, S. Ruffo, Phys. Rev. Lett. 98, 150602 (2007)
[39] C. Anteneodo, J.C. Dias, R.S. Mendes, Phys. Rev. E 73, 051105 (2006)
[40] C. Tsallis, R.S. Mendes, A.R. Plastino, Physica A 261, 534 (1998)
[41] S. Umarov, C. Tsallis, S. Steinberg, Milan J. Math. (2008), DOI: 10.1007/s00032-008- 0087-y
[42] C. Vignat, A. Plastino, J. Phys. A 40, F969 (2007)
[43] J. Mathews, R.L. Walker, Mathematical Methods of Physics (Addison-Wesley, Reading, Massachusetts, 1970) · Zbl 0124.39201
[44] D.S. Zhang, G.W. Wei, D.J. Kouri, D.K. Hoffman, Phys. Rev. E 56, 1197 (1997)
[45] C. Tsallis, A.R. Plastino, R.F. Alvarez-Estrada (2008), eprint arXiv: cond-mat.stat-mech/0802.1698
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.