Sökning: "critical exponent"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden critical exponent.

  1. 1. Critical Phenomena and Exchange Coupling in Magnetic Heterostructures

    Författare :Martina Ahlberg; Gabriella Andersson; Björgvin Hjörvarsson; Steve Bramwell; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phase transitions; critical behavior; 2D XY model; MOKE; magnetic thin films and superlattices; amorphous multilayers; magnetic proximity effects; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The continuous phase transition in thin magnetic films and superlattices has been studied using the magneto-optical Kerr effect (MOKE) and polarized neutron scattering (PNR).  It has been shown that the critical behavior of amorphous thin films belonging to the 2D XY universality class can be described within the same theory as crystalline sample. LÄS MER

  3. 2. Gibbs Measures and Phase Transitions in Potts and Beach Models

    Författare :Per Hallberg; KTH; []
    Nyckelord :Potts model; beach model; percolation; random-cluster model; Gibbs measure; coupling; Markov chains on infinite trees; critical exponent;

    Sammanfattning : The theory of Gibbs measures belongs to the borderlandbetween statistical mechanics and probability theory. In thiscontext, the physical phenomenon of phase transitioncorresponds to the mathematical concept of non-uniqueness for acertain type of probability measures.The most studied model in statistical mechanics is thecelebrated Ising model. LÄS MER

  4. 3. Numerical analysis and simulation of stochastic partial differential equations with white noise dispersion

    Författare :André Berg; David Cohen; Per Åhag; Guillaume Dujardin; Ludovic Goudenège; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stochastic partial differential equation; mathematics; numerical analysis; numerical scheme; time integrator; convergence analysis; blowup; critical exponent; nonlinear Schrödinger equation; Manakov equation; Benjamin-Bona-Mahony equation; BBM equation; stochastic; random; dispersion; white noise dispersion; finite difference; pseudospectral; code; matlab; exponential integrator; splitting integrator; convergence in probability; Mathematics; matematik; Numerical Analysis; numerisk analys;

    Sammanfattning : This doctoral thesis provides a comprehensive numerical analysis and exploration of several stochastic partial differential equations (SPDEs). More specifically, this thesis investigates time integrators for SPDEs with white noise dispersion. LÄS MER

  5. 4. Topics in Nonlinear Elliptic Differential Equations

    Författare :Shoyeb Waliullah; Andrzej Szulkin; Thomas Bartsch; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Concentration-compactness principle; critical Sobolev exponent; symmetric solutions of elliptic equations; degenerate elliptic equation; Nehari manifold; Caffarelli-Kohn-Nirenberg inequality; infinitely many solutions; MATHEMATICS; MATEMATIK; Mathematics; matematik;

    Sammanfattning : In this thesis we examine the existence of solutions to nonlinear elliptic partial differential equations via variational methods.In Paper I we consider the existence of constrained minimizers which correspond to solutions of equations involving the iterated Laplacian, the iterated p-Laplacian and the critical Sobolev exponent. LÄS MER

  7. 5. Active Matter in a Critical State: From passive building blocks to active molecules, engines, and active droplets

    Författare :Falko Schmidt; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; active matter; nonequilibrium; self-assembly; microswimmers; nanomotors; optical tweezers; colloidal molecules; active droplets; critical Casimir forces;

    Sammanfattning : The motion of microscopic objects is strongly affected by their surrounding environment. In quiescent liquids, motion is reduced to random fluctuations known as Brownian motion. Nevertheless, microorganisms have been able to develop mechanisms to generate active motion. LÄS MER