Search for dissertations about: "collective models"

Showing result 16 - 20 of 118 swedish dissertations containing the words collective models.

  2. 16. Studies of collective phenomena in neutron deficient nuclei : by means of lifetime measurements, angular correlation measurements and the recoil-decay tagging technique

    Author : Karin Andgren; Bo Cederwall; Paul Nolan; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; heavy-ion reactions; multi-detector arrays; recoil separator; in-beam gamma-ray spectroscopy; high spin states; lifetime measurements; recoil-decay tagging; nuclear shape; Nuclear physics; Kärnfysik;

    Abstract : The nucleus is a mesoscopic system that retains features from both the quantum and macroscopic worlds. A basic property of a macroscopic body is its shape. Nuclear shapes can be deduced from experimental data as they influence the excitation mode of the nucleus and hence the energies and lifetimes of its excited levels. READ MORE

  4. 17. QED and collective effects in vacuum and plasmas

    Author : Joakim Lundin; Mattias Marklund; Thomas Heinzl; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; QED; quantum electrodynamics; quantum plasmas; quantum vacuum; Plasma physics; Plasmafysik; fysik; Physics;

    Abstract : The theory of quantum electrodynamics (QED) was born out of an attempt to merge Einsteins theory of special relativity and quantum mechanics. Einsteins energy/mass equivalence together with Heisenberg's uncertainty principle allows for particle pairs to be spontaneously created and annihilated in vacuum. READ MORE

  5. 18. Holographic descriptions of collective modes in strongly correlated media

    Author : Marcus Tornsö; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; plasmonics; strongly correlated media; holography; gauge gravity duality; graphene; strong coupling; quasinormal modes;

    Abstract : Solving the puzzle of high temperature superconductivity may be one of the most desired scientific breakthroughs of our time, as access to room temperature superconductivity could revolutionize society as we know it. In this thesis, we strive to increase the theoretical understanding of such matter, by studying the phase above, in temperature, the superconducting phase - the "strange metal". READ MORE

  6. 19. Models for Rotating Nuclei - Cranking and Rotor + Particles Coupling

    Author : Gillis Carlsson; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; high-spin masses; 58Ni; particle rotor model; 86Nb; 163Lu; wobbling; cranking;

    Abstract : This dissertation investigates properties of rotating atomic nuclei. Studies are performed using the cranking model and in the particles + rotor model. Properties studied are energy spectra and electromagnetic transition probabilities. READ MORE

  7. 20. On Models of Quantum Plasmas and their Nonlinear Implications

    Author : Martin Stefan; Gert Brodin; Mattias Marklund; Tito Mendonca; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : The theory of quantum plasmas dates back to the first attempts of Wigner, Moyal and others to find a suitable formalism to describe many body quantum systems, and from this foundation a rich field has emerged. A plasma is a system consisting of many charged particles, and in a quantum plasma these particles have quantum mechanical properties, such as for example spin. READ MORE