Essays about: "Lattice theory"

Showing result 1 - 5 of 54 essays containing the words Lattice theory.

  1. 1. Z2-Gauge Theory with Matter : Dispersive behaviour of a dimer in a 1+1-dimensional lattice

    University essay from Karlstads universitet/Institutionen för ingenjörsvetenskap och fysik (from 2013)

    Author : Filip Ekblom; [2023]
    Keywords : Spin chain; Ising model; Dimer; Lattice; Lattice gauge theory;

    Abstract : The intention with this thesis is to investigate a dimer in a spin chain. Inorder to do that, a model from Z2-gauge theory is taken as the theoretical motivation to construct a discrete lattice with Ising spin properties. A dimer is then allowed to exist indirectly in the empty space between sites. READ MORE

  3. 2. First principles investigation of the thermal conductivity of Zr, ZrC, and ZrN

    University essay from KTH/Fysik

    Author : Daniel Karlsson; [2023]
    Keywords : Electron-phonon interaction; Density functional theory; Boltzmann transport equation; first-principles; thermal conductivity; electrical resistivity; Abinit; Phono3py; Elektron-fononväxelverkan; täthetsfunktionalteori; Boltzmanns transportekvation; värmeledningsförmåga; elektrisk resistivitet; Abinit; Phono3py;

    Abstract : The thermal conductivity and electrical resistivity of Zr, ZrC, and ZrN were calculated using first-principles density functional theory (DFT) and the Boltzmann transport equation. The electron-phonon scattering was modeled via the self-energy relaxation time approximation (SERTA), and the phonon-phonon scattering via the analogous single-mode relaxation time approximation (SMRTA). READ MORE

  4. 3. Numerical Estimation of Critical Exponents in the 3D XY Model

    University essay from KTH/Fysik

    Author : Christoffer Beiming; [2023]
    Keywords : Theoretical physics; Condensed matter theory; Phase transitions; XY model; Critical exponents; Computational physics; Monte Carlo simulations; Teoretisk fysik; Kondenserade materiens teori; Fasövergångar; XY-modellen; Kritiska exponenter; Beräkningsfysik; Monte Carlo simulering;

    Abstract : The experimentally obtained value of the critical exponent ν is presently in significant disagreement with current theoretical predictions for the λ-universality class. We suggest two novel approaches of determining the exponents ν and η by utilizing the effects of finite size scaling. READ MORE

  5. 4. Studies of the axial-vector transition form factors of the process Ω− → W−Ξ0 in chiral perturbation theory

    University essay from Uppsala universitet/Kärnfysik

    Author : Hélène De Munck; [2023]
    Keywords : Transition form Factors; Next-to-next-to-leading order; chiral perturbation theory; axial-vector; Ω− → W−Ξ0;

    Abstract : This work is included in a broader research of the hadron theory group of Uppsala University and its collaborators tackling the quest for an understanding of the quark distribution inside hadrons by joining threedifferent approaches of QCD namely chiral perturbation theory, dispersion theory and lattice QCD. This thesis contributes by computing in chiral perturbation theory, the quark-masses dependence of form factors. READ MORE

  6. 5. Moving in the dark : Mathematics of complex pedestrian flows

    University essay from Karlstads universitet/Fakulteten för hälsa, natur- och teknikvetenskap (from 2013)

    Author : Meghashyam Veluvali; [2023]
    Keywords : Mathematical modelling of pedestrian dynamics; stochastic systems; evacuation time; random walk method; parabolic equation; finite difference method;

    Abstract : The field of mathematical modelling for pedestrian dynamics has attracted significant scientific attention, with various models proposed from perspectives such as kinetic theory, statistical mechanics, game theory and partial differential equations. Often such investigations are seen as being a part of a new branch of study in the domain of applied physics, called sociophysics. READ MORE