1st Edition

The Fractional Laplacian

By C. Pozrikidis Copyright 2016
    294 Pages 74 B/W Illustrations
    by Chapman & Hall

    294 Pages 74 B/W Illustrations
    by Chapman & Hall

    The fractional Laplacian, also called the Riesz fractional derivative, describes an unusual diffusion process associated with random excursions. The Fractional Laplacian explores applications of the fractional Laplacian in science, engineering, and other areas where long-range interactions and conceptual or physical particle jumps resulting in an irregular diffusive or conductive flux are encountered.

    • Presents the material at a level suitable for a broad audience of scientists and engineers with rudimentary background in ordinary differential equations and integral calculus
    • Clarifies the concept of the fractional Laplacian for functions in one, two, three, or an arbitrary number of dimensions defined over the entire space, satisfying periodicity conditions, or restricted to a finite domain
    • Covers physical and mathematical concepts as well as detailed mathematical derivations
    • Develops a numerical framework for solving differential equations involving the fractional Laplacian and presents specific algorithms accompanied by numerical results in one, two, and three dimensions
    • Discusses viscous flow and physical examples from scientific and engineering disciplines

    Written by a prolific author well known for his contributions in fluid mechanics, biomechanics, applied mathematics, scientific computing, and computer science, the book emphasizes fundamental ideas and practical numerical computation. It includes original material and novel numerical methods.

    The fractional Laplacian in one dimension
    Random walkers with constant steps
    Ordinary diffusion
    Random jumpers
    Central limit theorem and stable distributions
    Power-law probability jump lengths
    A principal-value integral
    Wires and springs
    The fractional Laplacian
    Fourier transform
    Effect of fractional order
    Numerical computation of the fractional Laplacian
    Green’s function of the fractional Laplace equation
    Fractional Poisson equation in a restricted domain
    Green’s function of unsteady fractional diffusion

    Numerical discretization in one dimension
    Computation of a principal-value integral
    Fractional Laplacian differentiation matrix
    Fractional Poisson equation
    Evolution under fractional diffusion
    Differentiation by spectral expansion

    Further concepts in one dimension
    Fractional first derivative
    Properties of the fractional first derivative
    Laplacian potential
    Fractional derivatives from finite-difference stencils
    Fractional third derivative
    Fractional fourth derivative

    Periodic functions
    Sine, cosines, and the complete Fourier series
    Cosine Fourier series
    Sine Fourier series
    Green’s functions
    Integral representation of the periodic Laplacian
    Numerical discretization
    Periodic differentiation matrix
    Differentiation by spectral expansion
    Embedding of the fractional Poisson equation

    The fractional Laplacian in three dimensions
    Stipulation on the Fourier transform
    Integral representation
    Fractional gradient
    Laplacian potential
    Green’s function of the fractional Laplace equation
    The Riesz potential
    Triply periodic Green’s function
    Fractional Poisson equation
    Evolution under fractional diffusion
    Periodic functions and arbitrary domains
    Fractional Stokes flow

    The fractional Laplacian in two dimensions
    Stipulation on the Fourier transform
    Integral representation
    Fractional gradient
    Laplacian potential
    Green’s function of the fractional Laplace equation
    The Riesz potential
    Doubly periodic Green’s function
    Fractional Poisson equation
    Evolution due to fractional diffusion
    Periodic functions and arbitrary domains

    Appendix A: Selected definite integrals
    Appendix B: The Gamma function
    Appendix C: The Gaussian distribution
    Appendix D: The fractional Laplacian in arbitrary dimensions
    Appendix E: Fractional derivatives
    Appendix F: Aitken extrapolation of an infinite sum

    References

    Index

    Biography

    Constantine Pozrikidis is a professor at the University of Massachusetts Amherst. He is well known for his contributions in fluid mechanics, biomechanics, applied mathematics, scientific computing, and computer science. He is the author of numerous research papers and books, including the highly recommended Chapman & Hall/CRC books Introduction to Finite and Spectral Element Methods Using MATLAB®, Second Edition; XML in Scientific Computing; Computational Hydrodynamics of Capsules and Biological Cells; Modeling and Simulation of Capsules and Biological Cells; and A Practical Guide to Boundary Element Methods with the Software Library BEMLIB.

    "The book under review includes an introductory discussion on the fractional Laplacian which should be accessible to scientists who may not be mathematicians. Practical numerical computations are particularly emphasized, and the book includes many exercises. The fundamental ideas are presented without the traditional organization into theorems and proofs. Here is the list of chapter headings: 1. The fractional Laplacian in one dimension. 2. Numerical discretization in one dimension. 3. Further concepts in one dimension. 4. Periodic functions. 5. The fractional Laplacian in three dimensions. 6. The fractional Laplacian in two dimensions. There are also several appendices: A. Selected de nite integrals. B. The Gamma function. C. The Gaussian distribution. D. The fractional Laplacian in arbitrary dimensions. E. Fractional derivatives. F. Aitken extrapolation of an in nite sum."
    ~Daniel Belita, Mathematical Reviews, 2017