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Fokker–Planck Equations for a Free Energy Functional or Markov Process on a Graph

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Abstract

The classical Fokker–Planck equation is a linear parabolic equation which describes the time evolution of the probability distribution of a stochastic process defined on a Euclidean space. Corresponding to a stochastic process, there often exists a free energy functional which is defined on the space of probability distributions and is a linear combination of a potential and an entropy. In recent years, it has been shown that the Fokker–Planck equation is the gradient flow of the free energy functional defined on the Riemannian manifold of probability distributions whose inner product is generated by a 2-Wasserstein distance. In this paper, we consider analogous matters for a free energy functional or Markov process defined on a graph with a finite number of vertices and edges. If N ≧ 2 is the number of vertices of the graph, we show that the corresponding Fokker–Planck equation is a system of N nonlinear ordinary differential equations defined on a Riemannian manifold of probability distributions. However, in contrast to stochastic processes defined on Euclidean spaces, the situation is more subtle for discrete spaces. We have different choices for inner products on the space of probability distributions resulting in different Fokker–Planck equations for the same process. It is shown that there is a strong connection but there are also substantial discrepancies between the systems of ordinary differential equations and the classical Fokker–Planck equation on Euclidean spaces. Furthermore, both systems of ordinary differential equations are gradient flows for the same free energy functional defined on the Riemannian manifolds of probability distributions with different metrics. Some examples are also discussed.

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References

  1. Ait-Haddou R., Herzog W.: Brownian ratchet models of molecular motors. Cell Bioch. Biophys. 38(2), 191–213 (2003)

    Article  Google Scholar 

  2. Ambrosio, L., Gigli, N., Savaré, G.: Gradient Flows: in Metric Spaces and in the Space of Probability Measures. Birkhäuser, 2008

  3. Astumian R.D.: Thermodynamics and kinetics of a Brownian motor. Science 276(5314), 917 (1997)

    Article  Google Scholar 

  4. Bergmann P.G., Lebowitz J.L.: New approach to nonequilibrium processes. Phys. Rev. 99(2), 578 (1955)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  5. Bonciocat A.I., Sturm K.T.: Mass transportation and rough curvature bounds for discrete spaces. J. Funct. Anal. 256(9), 2944–2966 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  6. Buet C., Cordier S.: Numerical analysis of conservative and entropy schemes for the Fokker-Planck-Landau equation. SIAM J. Numerical Anal. 36, 953–973 (1999)

    Article  MathSciNet  Google Scholar 

  7. Carlen E.A., Gangbo W.: Constrained steepest descent in the 2-Wasserstein metric. Ann. Math. 157, 807–846 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  8. Carlen E.A., Gangbo W.: Solution of a model boltzmann equation via steepest descent in the 2-Wasserstein metric. Arch. Rational Mech. Anal. 172(1), 21–64 (2004)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  9. Chow S.N., Huang W., Li Y., Zhou H.: A free energy based mathematical study for molecular motors. Regular Chaotic Dyn. 16(1), 117–127 (2011)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  10. Cordero-Erausquin, D., Gangbo, W., Houdré, C.: Inequalities for generalized entropy and optimal transportation. Recent Advances in the Theory and Applications of Mass Transport: Summer School on Mass Transportation Methods in Kinetic Theory and Hydrodynamics, September 4–9, 2000, Ponta Delgada, Azores, Portugal 353, 73 (2004)

  11. Cordero-Erausquin D., McCann R.J., Schmuckenschläger M.: A Riemannian interpolation inequality à la Borell, Brascamp and Lieb. Invent. Math. 146(2), 219–257 (2001)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  12. Van den Broeck, C.: The master equation and some applications in physics. Stoch. Process. Appl. Phys. 1–28 (1985)

  13. Dobrushin R.L.: Prescribing a system of random variables by conditional distributions. Theory Probab. Appl. 15, 458 (1970)

    Article  MATH  Google Scholar 

  14. Dolbeault, J., Kinderlehrer, D., Kowalczyk, M.: Remarks about the flashing rachet. Partial Differential Equations and Inverse Problems, 167–175. Contemp. Math., vol. 362

  15. Ellis, R.S.: Entropy, Large Deviations, and Statistical Mechanics, vol. 271. Springer, 1985

  16. Evans, L.C.: Entropy and Partial Differential Equations. Lecture Notes at UC Berkeley

  17. Evans, L.C.: Partial differential equations and Monge-Kantorovich mass transfer. Current Developments in Mathematics, 65–126 (1997)

  18. Evans, L.C., Gangbo, W.: Differential Equations ethods for the Monge-Kantorovich Mass Transfer-Problem, vol.137. American Mathematical Society, 1999

  19. Gardiner, C.W.: Handbook of Stochastic Methods for Physics, Chemistry and Natural Sciences, 4th printing of the 2nd edn, 1997

  20. Gilbarg, D., Trudinger, N.S.: Elliptic Partial Differential Equations of Second Order, 2001

  21. Hao, G., Kim, W.H., Qian, H.: Thermodynamics and Geometry of Reversible and Irreversible Markov Processes. Preprint

  22. Harmer G.P., Abbott D.: Game theory: losing strategies can win by Parrondo’s paradox. Nature 402(6764), 864–864 (1999)

    Article  ADS  Google Scholar 

  23. Harmer G.P., Abbott D.: A review of Parrondos paradox. Fluct. Noise Lett. 2(2), R71–R107 (2002)

    Article  Google Scholar 

  24. Heath D., Kinderlehrer D., Kowalczyk M.: Discrete and continuous ratchets: from coin toss to molecular motor. Discrete Contin. Dyn. Syst. B 2(2), 153–168 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  25. Jordan R., Kinderlehrer D., Otto F.: Free energy and the Fokker-Planck equation. Physica D: Nonlinear Phenom. 107(2–4), 265–271 (1997)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  26. Jordan R., Kinderlehrer D., Otto F.: The variational formulation of the Fokker-Planck equation. SIAM J. Math. Anal. 29(1), 1–17 (1998)

    Article  MathSciNet  MATH  Google Scholar 

  27. LeVeque, R.J.: Numerical Methods for Conservation Laws. Birkhäuser, 1992

  28. Lott J.: Some geometric calculations on Wasserstein space. Commun. Math. Phys. 277(2), 423–437 (2008)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  29. Lott J., Villani C.: Ricci curvature for metric-measure spaces via optimal transport. Ann. Math. 169, 903–991 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  30. Mathews D.H., Turner D.H.: Prediction of rna secondary structure by free energy minimization. Curr. Opin. Struct. Biol. 16(3), 270–278 (2006)

    Article  Google Scholar 

  31. McCann R.J.: Exact solutions to the transportation problem on the line. Proc. R. Soc. Lond. A: Math. Phys. Eng. Sci. 455(1984), 1341 (1999)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  32. Mielke A.: A gradient structure for reaction–diffusion systems and for energy-drift-diffusion systems. Nonlinearity 24, 1329 (2011)

    Article  MathSciNet  ADS  MATH  Google Scholar 

  33. Otto F.: The geometry of dissipative evolution equations: the porous medium equation. Commun. Partial Differ. Equ. 26(1–2), 101–174 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  34. Otto F., Villani C.: Generalization of an inequality by Talagrand and links with the logarithmic Sobolev inequality. J. Funct. Anal. 173(2), 361–400 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  35. Otto F., Westdickenberg M.: Eulerian calculus for the contraction in the Wasserstein distance. SIAM J. Math. Anal. 37(4), 1227–1255 (2005)

    Article  MathSciNet  Google Scholar 

  36. Percus O.E., Percus J.K.: two wrongs make a right? Coin-tossing games and Parrondos paradox. Math. Intell. 24(3), 68–72 (2002)

    Article  MathSciNet  Google Scholar 

  37. Qian H.: Motor protein with nonequilibrium potential: its thermodynamics and efficiency. Phys. Rev. E 69(1), 012901 (2004)

    Article  ADS  Google Scholar 

  38. Qian H.: Cycle kinetics, steady state thermodynamics and motors—a paradigm for living matter physics. J. Phys. Condens. Matter 17, S3783 (2005)

    Article  ADS  Google Scholar 

  39. Qian M., Zhang X., Wilson R.J., Feng J.: Efficiency of Brownian motors in terms of entropy production rate. Europhys. Lett. 84, 10014 (2008)

    Article  MathSciNet  ADS  Google Scholar 

  40. Risken, H.: The Fokker-Planck Equation: Methods of Solution and Applications, vol. 18. Springer, 1996

  41. Sammer M., Tetali P.: Concentration on the discrete torus using transportation. Combin. Probab. Comput. 18(5), 835–860 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  42. Schuss, Z.: Singular perturbation methods in stochastic differential equations of mathematical physics. SIAM Rev. 22, 119–155 (1980)

    Article  MathSciNet  MATH  Google Scholar 

  43. Smolka, B., Wojciechowski, K.: Contrast enhancement of badly illuminated images based on Gibbs distribution and random walk model. CAIP’1997, 271–278, 1997

  44. Sturm K.T.: Generalized Ricci bounds and convergence of metric measure spaces. Comptes Rendus Math. 340(3), 235–238 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  45. Sturm K.T.: On the geometry of metric measure spaces . Acta Math. 196(1), 65–131 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  46. Sturm K.T.: On the geometry of metric measure spaces, II. Acta Math. 196(1), 133–177 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  47. Vaserstein L.N.: Markov processes over denumerable products of spaces, describing large systems of automata. Problemy Peredachi Informatsii 5(3), 64–72 (1969)

    MathSciNet  MATH  Google Scholar 

  48. Villani, C.: Topics in Optimal Transportation, vol. 58. American Mathematical Society, 2003

  49. Villani, C.: Optimal Transport: Old and New, vol. 338. Springer, 2009

  50. Von Renesse M.K., Sturm K.T.: Transport inequalities, gradient estimates, entropy and Ricci curvature. Commun. Pure Appl. Math. 58(7), 923–940 (2005)

    Article  MathSciNet  MATH  Google Scholar 

  51. Von Renesse M.K., Sturm K.T.: Entropic measure and Wasserstein diffusion. Ann. Probab. 37(3), 1114–1191 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  52. Wu, Y., Hua, G., Yu, T.: Tracking articulated body by dynamic Markov network. Proceedings of Ninth IEEE International Conference on Computer Vision, 2003. IEEE, 1094–1101, 2003

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Correspondence to Shui-Nee Chow.

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Communicated by D. Kinderlehrer

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Chow, SN., Huang, W., Li, Y. et al. Fokker–Planck Equations for a Free Energy Functional or Markov Process on a Graph. Arch Rational Mech Anal 203, 969–1008 (2012). https://doi.org/10.1007/s00205-011-0471-6

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  • DOI: https://doi.org/10.1007/s00205-011-0471-6

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