20,335 research outputs found

    Three-loop field renormalization for scalar field theory with Lorentz violation

    Get PDF
    Applying the counterterm method in minimal subtraction scheme we calculate the three-loop quantum correction to field anomalous dimension in a Lorentz-violating O(NN) self-interacting scalar field theory. We compute the Feynman diagrams using dimensional regularization and ϵ\epsilon-expansion techniques. As this approximation corresponds to a three-loop term, to our knowledge this is the first time in literature in which such a loop level is attained for a LV theory.Comment: 12 page

    A family of rotation numbers for discrete random dynamics on the circle

    Full text link
    We revisit the problem of well-defining rotation numbers for discrete random dynamical systems on the circle. We show that, contrasting with deterministic systems, the topological (i.e. based on Poincar\'{e} lifts) approach does depend on the choice of lifts (e.g. continuously for nonatomic randomness). Furthermore, the winding orbit rotation number does not agree with the topological rotation number. Existence and conversion formulae between these distinct numbers are presented. Finally, we prove a sampling in time theorem which recover the rotation number of continuous Stratonovich stochastic dynamical systems on S1S^1 out of its time discretisation of the flow.Comment: 15 page

    Gravitational fields with sources, regular black holes, quasiblack holes, and analogue black holes

    Full text link
    We discuss recent developments in gravitational fields with sources, regular black holes, quasiblack holes, and analogue black holes, related to the talks presented at the corresponding Parallel Session AT3 of the 13th Marcel Grossmann Meeting.Comment: Report of the Parallel Session AT3 at the Marcel Grossmann Meeting 13, Stockholm 2012, Proceedings of the Conference. 9 page

    Assessment of 48 Stock markets using adaptive multifractal approach

    Full text link
    Stock market comovements are examined using cointegration, Granger causality tests and nonlinear approaches in context of mutual information and correlations. Underlying data sets are affected by non-stationarities and trends, we also apply AMF-DFA and AMF-DXA. We find only 170 pair of Stock markets cointegrated, and according to the Granger causality and mutual information, we realize that the strongest relations lies between emerging markets, and between emerging and frontier markets. According to scaling exponent given by AMF-DFA, h(q=2)>1h(q=2)>1, we find that all underlying data sets belong to non-stationary process. According to EMH, only 8 markets are classified in uncorrelated processes at 2σ2\sigma confidence interval. 6 Stock markets belong to anti-correlated class and dominant part of markets has memory in corresponding daily index prices during January 1995 to February 2014. New-Zealand with H=0.457±0.004H=0.457\pm0.004 and Jordan with H=0.602±0.006H=0.602\pm 0.006 are far from EMH. The nature of cross-correlation exponents based on AMF-DXA is almost multifractal for all pair of Stock markets. The empirical relation, Hxy≤[Hxx+Hyy]/2H_{xy}\le [H_{xx}+H_{yy}]/2, is confirmed. Mentioned relation for q>0q>0 is also satisfied while for q<0q<0 there is a deviation from this relation confirming behavior of markets for small fluctuations is affected by contribution of major pair. For larger fluctuations, the cross-correlation contains information from both local and global conditions. Width of singularity spectrum for auto-correlation and cross-correlation are Δαxx∈[0.304,0.905]\Delta \alpha_{xx}\in [0.304,0.905] and Δαxy∈[0.246,1.178]\Delta \alpha_{xy}\in [0.246,1.178], respectively. The wide range of singularity spectrum for cross-correlation confirms that the bilateral relation between Stock markets is more complex. The value of σDCCA\sigma_{DCCA} indicates that all pairs of stock market studied in this time interval belong to cross-correlated processes.Comment: 16 pages, 13 figures and 4 tables, major revision and match to published versio
    • …
    corecore