Sökning: "recursion theory"

Visar resultat 21 - 25 av 26 avhandlingar innehållade orden recursion theory.

  1. 21. Multipole moments of axisymmetric spacetimes

    Författare :Thomas Bäckdahl; Magnus Herberthson; Brian Edgar; Kjell Rosquist; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; multipole moments; axisymmetry; spacetimes; prescribed; solutions; static; stationary; Kerr; Weyl; Ernst; Theory of relativity; gravitation; Relativitetsteori; gravitation;

    Sammanfattning : In this thesis we study multipole moments of axisymmetric spacetimes. Using the recursive definition of the multipole moments of Geroch and Hansen we develop a method for computing all multipole moments of a stationary axisymmetric spacetime without the use of a recursion. LÄS MER

  3. 22. First-principles Studies of Local Structure Effects in Magnetic Materials

    Författare :Marcio Costa; Anders Bergman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic anisotropy; DMFT; magnetism; DFT; Materialvetenskap; Materials Science;

    Sammanfattning : This thesis focus on the magnetic behavior, from single atoms to bulk materials. The materials considered in this thesis have been studied by computational methods based on ab initio theory, density functional theory (DFT), including treatment of the spin-orbit coupling, non-collinear magnetism, and methods capable of treating discorded systems. LÄS MER

  4. 23. Dynamics of Plates with Thin Piezoelectric Layers

    Författare :Karl Mauritsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thin layers; Actuator; Plate equations; Equivalent boundary conditions; Power series expansions; Piezoelectricity;

    Sammanfattning : The subject of this thesis is dynamics of plates with thin piezoelectric layers. Piezoelectric materials are often used in sensors and actuators and common applications for these are vibration control and ultrasonic transducers. LÄS MER

  5. 24. Codes on Graphs and More

    Författare :Florian Hug; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; convolutional codes; woven graph codes; Low-density parity-check LDPC codes; tailbiting codes; bit error probability; MacWilliams Identity;

    Sammanfattning : Modern communication systems strive to achieve reliable and efficient information transmission and storage with affordable complexity. Hence, efficient low-complexity channel codes providing low probabilities for erroneous receptions are needed. LÄS MER

  7. 25. Maximal Unitarity at Two Loops : A New Method for Computing Two-Loop Scattering Amplitudes

    Författare :Kasper J. Larsen; Lisa Freyhult; David Kosower; Joseph Minahan; Paul Heslop; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Amplitudes; NNLO calculations; Quantum Chromodynamics; Unitarity; Fysik med inriktning mot elementarpartikelfysik; Physics with specialization in Elementary Particle Physics;

    Sammanfattning : The study of scattering amplitudes beyond one loop is necessary for precision phenomenology for the Large Hadron Collider and may also provide deeper insights into the theoretical foundations of quantum field theory. In this thesis we develop a new method for computing two-loop amplitudes, based on unitarity rather than Feynman diagrams. LÄS MER