{ "id": "1712.00332", "version": "v1", "published": "2017-12-01T14:23:16.000Z", "updated": "2017-12-01T14:23:16.000Z", "title": "On a skewed and multifractal uni-dimensional random field, as a probabilistic representation of Kolmogorov's views on turbulence", "authors": [ "Laurent Chevillard", "Christophe Garban", "Rémi Rhodes", "Vincent Vargas" ], "categories": [ "math.PR", "math-ph", "math.MP" ], "abstract": "We construct, for the first time to our knowledge, a one-dimensional stochastic field $\\{u(x)\\}_{x\\in \\mathbb{R}}$ which satisfies the following axioms which are at the core of the phenomenology of turbulence mainly due to Kolmogorov: (i) Homogeneity and isotropy: $u(x) \\overset{\\mathrm{law}}= -u(x) \\overset{\\mathrm{law}}=u(0)$ (ii) Negative skewness (i.e. the $4/5^{\\mbox{\\tiny th}}$-law): \\\\ $\\mathbb{E}{(u(x+\\ell)-u(x))^3} \\sim_{\\ell \\to 0+} - C \\, \\ell\\,,$ \\, for some constant $C>0$ (iii) Intermittency: $\\mathbb{E}{|u(x+\\ell)-u(x) |^q} \\asymp_{\\ell \\to 0} |\\ell|^{\\xi_q}\\,,$ for some non-linear spectrum $q\\mapsto \\xi_q$ Since then, it has been a challenging problem to combine axiom (ii) with axiom (iii) (especially for Hurst indexes of interest in turbulence, namely $H<1/2$). In order to achieve simultaneously both axioms, we disturb with two ingredients a underlying fractional Gaussian field of parameter $H\\approx \\frac 1 3 $. The first ingredient is an independent Gaussian multiplicative chaos (GMC) of parameter $\\gamma$ that mimics the intermittent, i.e. multifractal, nature of the fluctuations. The second one is a field that correlates in an intricate way the fractional component and the GMC without additional parameters, a necessary inter-dependence in order to reproduce the asymmetrical, i.e. skewed, nature of the probability laws at small scales.", "revisions": [ { "version": "v1", "updated": "2017-12-01T14:23:16.000Z" } ], "analyses": { "subjects": [ "60K40", "76F55", "76F30" ], "keywords": [ "multifractal uni-dimensional random field", "kolmogorovs views", "probabilistic representation", "turbulence", "one-dimensional stochastic field" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }