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Scaling functions for finite-size corrections in EVS Zoltán Rácz Institute for Theoretical Physics Eötvös University Homepage:

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Presentation on theme: "Scaling functions for finite-size corrections in EVS Zoltán Rácz Institute for Theoretical Physics Eötvös University Homepage:"— Presentation transcript:

1 Scaling functions for finite-size corrections in EVS Zoltán Rácz Institute for Theoretical Physics Eötvös University E-mail: racz@general.elte.hu Homepage: cgl.elte.hu/~racz Collaborators: G. Györgyi N. Moloney K. Ozogány I. Jánosi I. Bartos Idea: EVS looks like a finite-size scaling problem of critical phenomena – try to use the methods learned there. Results: Finite size corrections to limiting distributions (i.i.d. variables). Numerics for the EVS of signals ( ). Improved convergence by using the right scaling variables. Distribution of annual maximum temperatures. Motivation: Problems: Slow convergence to limit-distributions. Not much is known about the EVS of correlated variables. ~100 years (data)~200 years (design)

2 EVS and finite-size scaling is measured : probability of lim Question: Question: Is there a limit distribution for ? lim Result: Result: Three possible limit distributions depending on the tail of the parent distribution,. i.i.d. variables :

3 Extreme value limit distributions: i.i.d. variables Fisher & Tippet (1928) Gnedenko (1941) Fisher-Tippet-Gumbel (exponential tail) Fisher-Tippet-Frechet (power law tail) Weibull (finite cutoff) Characteristic shapes of probability densities:

4 Gaussian signals Edwards- Wilkinson Random walk Random acceleration Mullins- Herring noise White noise Single mode, random phase Independent, nonidentically distributed Fourier modes with singular fluctuations Berman, 1964 Majumdar- Comtet, 2004 EVS

5 EVS and finite-size scaling is measured : probability of lim There is a limit distribution for. i.i.d. variables : Question: Question: What is the rate of convergence? How universal is it?

6 Slow convergence to the limit distribution (i.i.d., FTG class) The Gaussian results are characteristic for the whole FTG class except for

7 Finite-size correction to the limit distribution de Haan & Resnick, 1996 Gomes & de Haan, 1999 Fix the position and the scale of by, is determined. expand in substitute

8 Finite-size correction to the limit distribution For Gaussian Comparison with simulations: How universal is ? Signature of corrections?

9 Finite-size correction: How universal is ? Determines universality different (known) function Gauss class Exponential class Exponential class is unstable Crossovers between Gauss class Exponential class Weibull, Fisher-Tippett-Frechet?!

10 Convergence to the limit distribution. Size dependence of the skewness:

11 Maximum relative height distribution ( ) Majumdar & Comtet, 2004 Connection to the PDF of the area under Brownian excursion over the unit interval maximum height measured from the average height Result: Airy distribution Choice of scaling

12 Finite-size scaling : Schehr & Majumdar (2005) Solid-on-solid models:

13 Finite-size scaling : Derivation of … Assumption: carries all the first order finite size correction. Cumulant generating function Scaling with Expanding in : Shape relaxes faster than the position

14 Finite-size scaling : Scaling with the average Assumption: carries all the first order finite size correction (shape relaxes faster than the position). Cumulant generating function Scaling with Expanding in :

15 Finite-size scaling : Scaling with the standard deviation Assumption: relaxes faster than any other. Cumulant generating function Scaling with Expanding in : Faster convergence

16 Finite-size scaling: Comparison of scaling with and. Much faster convergence scaling

17 Possible reason for the fast convergence for ( ) Width distributions Antal et al. (2001, 2002) Cumulants of

18 Finite-size scaling of the cumulants Györgyi et al. cond-mat/0610 signals as problems of generalized random-acceleration. Path-integral formulation: Scaling: Cumulants:

19 Extreme statistics of Mullins-Herring interfaces ( ) and of random-acceleration generated paths

20 Skewness, kurtosis Distribution of the daily maximal temperature Scale for comparability Calculate skewness and kurtosis Put it on the map Reference values:

21 Yearly maximum temperatures Corrections to scaling Distribution in scaling


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