Search for dissertations about: "S-matrix"

Showing result 1 - 5 of 6 swedish dissertations containing the word S-matrix.

  2. 1. On string integrability : A journey through the two-dimensional hidden symmetries in the AdS/CFT dualities

    Author : Valentina Giangreco Marotta Puletti; Konstantin Zarembo; Gleb Arutyunov; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; String Theory; AdS-CFT correspondence; Integrable Field theory; Sigma models; S-matrix; Factorized Scattering; Physics; Fysik; Mathematical physics; Matematisk fysik; Theoretical Physics; teoretisk fysik;

    Abstract : One of the main topics in the modern String Theory are the conjectured string/gauge (AdS/CFT) dualities. Proving such conjectures is extremely difficult since the gauge and string theory perturbative regimes do not overlap. In this perspective, the discovery of infinitely many conserved charges, i.e. READ MORE

  4. 2. Ways of determining and characterising resonances in scattering processes

    Author : Ksenia Shilyaeva; Nils Elander; Dage Sundholm; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum scattering theory; complex scaling; resonances; Molecular physics; Molekylfysik; fysik; Physics;

    Abstract : Scattering cross sections very often display structures. To clarify if these structures correspond to resonances one has to check if they are poles of the scattering matrix (S-matrix) in the fourth quadrant of the complex momentum plane. Furthermore, the states corresponding to these poles also need to have an appropriate scattering amplitude. READ MORE

  5. 3. Nucleon-Nucleon Scattering in a Wave-Packet Formalism

    Author : Sean Miller; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; nuclear physics; chiral potentials; two-nucleon scattering;

    Abstract : In this thesis I analyse the prospect of leveraging statistical analyses of the strong nuclear interaction by using the wave-packet continuum discretisation (WPCD) method to efficiently compute nucleon-nucleon (NN) scattering observables on a graphics processing unit (GPU). The WPCD method gives approximate solutions to the S-matrix at multiple scattering energies at the cost of a single eigendecomposition of the NN channel Hamiltonian. READ MORE

  6. 4. Study of Mutual Coupling in Finite Antenna Arrays for Massive MIMO Applications

    Author : Tomislav Marinovic; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiple scattering; Massive MIMO; mutual coupling MC ; 5G; iterative methods; base station antenna BSA ;

    Abstract : This thesis focuses on the study of mutual coupling (MC) in finite antenna arrays for base station antennas (BSAs) for Massive multiple-input multiple-output (MIMO) applications, with an emphasis on the development of a computationally-efficient modeling technique for the analysis of MC which can be readily applied in the design or synthesis schemes for BSAs. Traditionally, the effects of MC have been ignored or underestimated in the analyses performed within the information-theoretic-based communities by assuming idealized antenna elements with no MC between them or by considering the fictitious isotropic radiator models. READ MORE

  7. 5. Finite Energy Electronic Correlationsin Low-Dimensional Systems

    Author : Daniel Bozi; Portugal Universidade do Minho; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : This thesis report deals with the 1D Hubbard model and the quantum objects that diagonalize the normal ordered Hubbard hamiltonian, among those the so called PseudoFermions (PFs). These PFs have no residual energy interactions, are eta-spin and spin zero objects, and are the scatterers and the scattering centers of the theory. READ MORE