Sökning: "Sigma models"

Visar resultat 21 - 25 av 30 avhandlingar innehållade orden Sigma models.

  1. 21. Microelectronics for the thumb-size ultrasound measurement system

    Författare :Jonny Johansson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industrial Electronics; Industriell elektronik;

    Sammanfattning : This thesis presents building blocks and strategies to reach the goal of a thumb-size autonomous ultrasound measurement system with wireless communication capabilities. The design of modern electronics is based on the possibility to accurately predict system behavior by the use of simulation tools. LÄS MER

  3. 22. Dualities, Symmetries and Unbroken Phases in String Theory : Probing the Composite Nature of the String

    Författare :Johan Engquist; Joseph Minahan; Charlotte Kristjansen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Theoretical Physics; String Theory; M-Theory; Higher Spin Gauge Theory; Super Yang-Mills Theory; Anti-de Sitter Spacetime; Singletons; Massless Higher Spin Gauge Fields; AdS CFT Correspondence; Spin Chains; Semiclassical Strings; Tensionless Limits; Conformal Symmetry; Supersymmetry; Higher Spin Gauge Symmetry; Integrability; Fysik; Physics; Fysik;

    Sammanfattning : The thesis treats aspects of string/M-theory in anti-de Sitter spacetimes and their supersymmetric completions. By applying the AdS/CFT correspondence, as well as models of spin chains and singletons, we try to attain a better understanding of the underlying symmetries and the unbroken phases of string/M-theory. LÄS MER

  4. 23. Quivers, superconformal field theories and higher symmetries

    Författare :Robert Moscrop; Michele Del Zotto; Johannes Walcher; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  5. 24. Superconformal D-branes and moduli spaces

    Författare :Cecilia Albertsson; Eric Bergshoeff; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Theoretical Physics; teoretisk fysik;

    Sammanfattning : The on-going quest for a single theory that describes all the forces of nature has led to the discovery of string theory. This is the only known theory that successfully unifies gravity with the electroweak and strong forces. LÄS MER

  7. 25. Studies on CMOS Digital-to-Analog Converters

    Författare :Jacob Wikner; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In this thesis we present an overview and study on digital-to-analog converters (DAC), mainly for communications applications. Especially, we look at some digital subscriber line (DSL) specifications and communication over twisted-pair channels. LÄS MER