Search for dissertations about: "theoretical quantum field theory"

Showing result 1 - 5 of 123 swedish dissertations containing the words theoretical quantum field theory.

  2. 1. Theoretical Studies of Cytochrome P450

    Author : Patrik Rydberg; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; Proteins; enzymology; Proteiner; enzymologi; Theoretical chemistry; transition-state force field; peroxidase; theoretical chemistry; molecular dynamics; density functional theory; cytochrome P450; porphyrin; haem; heme; kvantkemi; Teoretisk kemi;

    Abstract : The cytochromes P450 are a large enzyme family that is found in all living organisms and takes part in both endogenous and exogenous metabolism. They are primarily mono-oxygenases and perform a wide range of reactions. READ MORE

  4. 2. Quantum Chemical Interpretation of Protein Crystal Structure

    Author : Kristina Nilsson; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; structure; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi; protein; ComQum-X; Hess2FF; QM MM; hetero-compound; metal; oxidation state; protonation; force field; quantum refinement; refinement;

    Abstract : An initial model in the crystallographic structure determination process, usually contains many errors. To produce an accurate model, one must carry out several cycles of crystallographic refinement. READ MORE

  5. 3. Defects, renormalization and conformal field theory

    Author : Alexander Söderberg Rousu; Agnese Bissi; Pedro Liendo; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; defects; boundaries; replica twist defect; conformal field theory; quantum field theory; Coleman-Weinberg mechanism; renormalization group flows; Theoretical Physics; Teoretisk fysik;

    Abstract : Defects in quantum field theories appear in many different contexts and are of great physical interest. Among other things, defects are used to describe the Kondō effect in condensed matter, confinement in quantum chromodynamics, Rényi entropy in quantum information and cosmic strings in string theory. READ MORE

  6. 4. Theoretical studies of porphyrin proteins

    Author : Emma Sigfridsson; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; molecular mechanics; quantum chemical calculations; electrostatic potential charges; atomic charges; ferrochelatase; cytochrome; myoglobin; Porphyrin; haem; QM MM; reorganisation energy; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Abstract : Different aspects of porphyrin proteins have been studied with theoretical methods. For example, we have studied: - The importance of hydrogen bonds for the discrimination between carbon monoxide and molecular oxygen by myoglobin, the oxygen carrier in muscles, modelling the active site both in vacuum and in the protein matrix - The inner-sphere reorganisation energy during electron transfer for cytochromes compared to other electron-transfer proteins, such as blue copper proteins and Fe-S clusters - The role of porphyrin distortions in the reaction mechanism of ferrochelatase, the enzyme that inserts an iron ion into protoporphyrin IX to make haem - The interaction between different metal sites in ferrochelatase In these studies we have used density functional theory, classical force field methods, and a combination of quantum chemistry and molecular mechanics. READ MORE

  7. 5. Quivers, superconformal field theories and higher symmetries

    Author : Robert Moscrop; Michele Del Zotto; Johannes Walcher; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Quantum field theory; Supersymmetry; Conformal field theory; Quivers; Seiberg-Witten theory; Geometric engineering; Higher symmetries; Theoretical Physics; Teoretisk fysik; Machine learning; Maskininlärning;

    Abstract : Quantum field theory (QFT) currently provides our best description of the natural world. Over the past century, it has been able to accurately reproduce many experimental results to an astonishing degree of accuracy and predict the existence of new particles. Despite this, QFT suffers from several mathematical problems. READ MORE