Sökning: "random phase approximation"

Visar resultat 1 - 5 av 11 uppsatser innehållade orden random phase approximation.

  1. 1. Self-consistent dielectric formalism scheme for the paramagnetic electron gas under warm dense matter conditions

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Fotios Kalkavouras; [2022]
    Nyckelord :Warm Dense Matter WDM ; Quantum One-Component plasmas qOCP ; Vashishta-Singwi VS ; Dielectric Formalism;

    Sammanfattning : The present thesis aims to further a somewhat unexplored area of Warm Dense Matter (WDM) physics through the use of tools developed within the dielectric formalism. WDM is an exotic form of matter with densities close to the solid state and temperatures of several eV. LÄS MER

  3. 2. Approximation of General Semi-Markov Models Using Expolynomials

    Master-uppsats, KTH/Matematisk statistik

    Författare :Niklas Nyholm; [2021]
    Nyckelord :applied mathematics; Markov modelling; Semi-Markov process; approximation theory; expolynomial; phase-type distribution; reliability analysis; tillämpad matematik; Markov modellering; Semi-Markov process; approximations teori; expolynom; phase-type fördelning; riskanalys;

    Sammanfattning : Safety analysis is critical when developing new engineering systems. Many systems have to function under randomly occurring events, making stochastic processes useful in a safety modelling context. However, a general stochastic process is very challenging to analyse mathematically. LÄS MER

  4. 3. Evaluation of Robust Model Building Tools to Improve the Efficiency of Non-linear Mixed Effect Model Building Workflows

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Institutionen för farmaci

    Författare :Karin Norgren; [2021]
    Nyckelord :Population PK modeling; Pharmacometrics; NLME modeling;

    Sammanfattning : Population PK models aim to describe the change in drug concentration over time for a specific population. The populations in population PK modelling often refer to subjects in a clinical trial of a potential drug candidate. LÄS MER

  5. 4. The self-screening correction to RPA and GW – A model and ab initio study

    Master-uppsats, Lunds universitet/Matematisk fysik; Lunds universitet/Fysiska institutionen

    Författare :Viktor Christiansson; [2019]
    Nyckelord :GW approximation; GWA; Random-Phase-Approximation; RPA; Self-screening; Self-screening correction; Beyond RPA; Beyond GW; Physics and Astronomy;

    Sammanfattning : The self-screening error in the GW approximation is studied by applying correction schemes beyond the random-phase approximation in model and ab inito calculations. Two model systems in the form of Hubbard dimers, with one and two orbitals per site respectively, are considered. LÄS MER

  7. 5. Model study of the linear density response function - A comparison between the exact result and RPA

    Kandidat-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Matematisk fysik

    Författare :Viktor Christiansson; [2017]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : The time-ordered linear density response function is examined in a model study. Two model dimers are considered; one with one orbital per site and a second one with two orbitals per site. The one-orbital case has U0, the on-site Coulomb interaction, as the only parameter and is solved analytically. LÄS MER