Now showing items 21-40 of 115

    • Examples of varieties with index one on C1 fields 

      Dan A.; Kaur I. (Journal of Number Theory, 2019-04-16)
      Let K be the fraction field of a Henselian discrete valuation ring with algebraically closed residue field k. In this article we give a sufficient criterion for a projective variety over such a field to have index 1.
    • Existence of “$d$-wave” Pairs and Density Waves in a Class of Microscopic Models for High Transition Temperature Superconductors 

      de Pasquale A.D. (2018-03-21)
      High-temperature superconductors have different properties than conventional superconductors, one of these important properties is non-isotropic symmetry of the order parameter. In this work we present a model that shows ...
    • Finite-energy Lévy-type motion through heterogeneous ensemble of Brownian particles 

      Sliusarenko O.; Vitali S.; Sposini V.; Paradisi P.; Chechkin A.; Castellani G.; Pagnini G. (Journal of Physics A: Mathematical and Theoretical, 2019-02-01)
      Complex systems are known to display anomalous diffusion, whose signature is a space/time scaling $x \sim t^\delta$ with $\delta \neq 1/2$ in the probability density function (PDF). Anomalous diffusion can emerge jointly ...
    • Fire-spotting generated fires. Part I: The role of atmospheric stability 

      Egorova V.; Trucchia A.; Pagnini G. (Applied Mathematical Modelling, 2019-02)
      This is the first part of two papers concerning fire-spotting generated fires. In this part we deal with the impact of macroscale factors, such as the atmospheric stability, and in the second part we deal with mesoscale ...
    • Fractional Brownian motion in a finite interval: correlations effect depletion or accretion zones of particles near boundaries 

      Guggenberger T.; Pagnini G.; Vojta T.; Metzler R. (New Journal of Physics, 2019-02)
      Fractional Brownian motion (FBM) is a Gaussian stochastic process with stationary, long-time correlated increments and is frequently used to model anomalous diffusion processes. We study numerically FBM confined to a finite ...
    • Fractional kinetics emerging from ergodicity breaking in random media 

      Molina-Garcia D.; Minh Pham T.; Paradisi P.; Manzo C.; Pagnini G. (Physical Review E, 2016)
      We present a modelling approach for diffusion in a complex medium characterized by a random lengthscale. The resulting stochastic process shows subdiffusion with a behavior in qualitative agreement with single particle ...
    • Fractional kinetics in random/complex media 

      Pagnini G. (Handbook of Fractional Calculus with Applications Volume 5 Applications in Physics, Part B, 2019)
      In this chapter, we consider a randomly-scaled Gaussian process and discuss a number of applications to model fractional diffusion. Actually, this approach can be understood as a Gaussian diffusion in a medium characterized ...
    • Fractional relaxation with time-varying coefficient 

      Garra R.; Giusti A.; Mainardi F.; Pagnini G. (Fractional Calculus and Applied Analysis, 2014-12-31)
      From the point of view of the general theory of the hyper-Bessel operators, we consider a particular operator that is suitable to generalize the standard process of relaxation by taking into account both memory effects of ...
    • From G - Equation to Michelson - Sivashinsky Equation in Turbulent Premixed Combustion Modelling 

      Pagnini G. (Proceedings/Extended Abstract Book (6 pages) of the XXXIX Meeting of the Italian Section of the Combustion Institute, Naples, Italy, 2017-06-20)
      It is well known that the Michelson-Sivashinky equation describes hydrodynamic instabilities in turbulent premixed combustion. Here a formulation of the flame front propagation based on the G-equation and on stochastic ...
    • From the 2nd Law of Thermodynamics to AC–Conductivity Measures of Interacting Fermions in Disordered Media 

      Bru J.-B.; de Siqueira Pedra W. (Mathematical Models and Methods in Applied Sciences, 2015-05-20)
      We study the dynamics of interacting lattice fermions with random hopping amplitudes and random static potentials, in presence of time-dependent electromagnetic fields. The interparticle interaction is short-range and ...
    • Front Curvature Evolution and Hydrodynamics Instabilities 

      Pagnini G.; Trucchia A. (Proceedings/Extended Abstract Book (6 pages) of the XXXX Meeting of the Italian Section of the Combustion Institute, Rome, Italy, 2017-06-07)
      It is known that hydrodynamic instabilities in turbulent premixed combustion are described by the Michelson-Sivashinsky (MS) equation. A model of the flame front propagation based on the G-equation and on stochastic ...
    • Front propagation in anomalous diffusive media governed by time-fractional diffusion 

      Mentrelli A.; Pagnini G. (Journal of Computational Physics, 2014-12-31)
      In this paper, a multi-dimensional model is proposed to study the propagation of random fronts in media in which anomalous diffusion takes place. The front position is obtained as the weighted mean of fronts calculated by ...
    • Front Propagation in Random Media 

      Trucchia A. (2019)
      This PhD thesis deals with the problem of the propagation of fronts under random circumstances. A statistical model to represent the motion of fronts when are evolving in a media characterized by microscopical randomness ...
    • Gaussian processes in complex media: new vistas on anomalous diffusion 

      Di Tullio F.; Paradisi P.; Spigler R.; Pagnini G. (Front. Phys., 2019-09)
      Normal or Brownian diffusion is historically identified by the linear growth in time of the variance and by a Gaussian shape of the displacement distribution. Processes departing from the at least one of the above conditions ...
    • General tête-à-tête graphs and Seifert manifolds 

      Portilla Cuadrado P. (2018-02-10)
      Tête-à-tête graphs and relative tête-à-tête graphs were introduced by N. A’Campo in 2010 to model monodromies of isolated plane curves. By recent work of Fdez de Bobadilla, Pe Pereira and the author, they provide a way ...
    • Geometric inequalities from phase space translations 

      Huber S.; König R.; Vershynina A. (2016-07-22)
      We establish a quantum version of the classical isoperimetric inequality relating the Fisher information and the entropy power of a quantum state. The key tool is a Fisher information inequality for a state which results ...
    • Heat production of noninteracting fermions subjected to electric fields 

      Bru J.-B.; de Siqueira Pedra W.; Hertling C. (Communications on Pure and Applied Mathematics, 2014-07-21)
      Electric resistance in conducting media is related to heat (or entropy) production in the presence of electric fields. In this paper, by using Araki's relative entropy for states, we mathematically define and analyze the ...
    • Homogeneous singularity and the Alexander polynomial of a projective plane curve 

      Thuong L.Q.; Tai P.D.; Hoang Lan N.P. (2017-12-10)
      The Alexander polynomial of a plane curve is an important invariant in global theories on curves. However, it seems that this invariant and even a much stronger one the fundamental group of the complement of a plane curve ...
    • Hölder equivalence of complex analytic curve singularities 

      Fernandes A.; Sampaio J. E.; Silva J. P. (Bulletin of the London Mathematical Society, 2018-08-06)
      We prove that if two germs of irreducible complex analytic curves at $0\in\mathbb{C}^2$ have different sequence of characteristic exponents, then there exists $0<\alpha<1$ such that those germs are not $\alpha$-H\"older ...