Sökning: "String Stability"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden String Stability.

  1. 1. Vacua in String Theory : de Sitter Space and Stability in Flux Compactifications

    Författare :Sergio C. Vargas; Ulf Danielsson; Alessandro Tomasiello; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; String theory; Cosmology; Flux Compactifications; Landscape; Swampland;

    Sammanfattning : Our understanding of cosmology has evolved radically in the last decades. Current models demand the presence of dark energy in our universe and the most favored candidate behind this component is a small positive cosmological constant that characterizes a de Sitter (dS) spacetime. LÄS MER

  3. 2. On Cooperative Control of Automated Driving Systems from a Stability and Safety Perspective

    Författare :Roozbeh Kianfar; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reachability Analysis; Intelligent Transportation; Platooning; String Stability; Distributed Control;

    Sammanfattning : Over the last few decades, congested traffic network have become a seriousproblem in many countries. Congestions result in time losses, increase of fuelconsumption and also raise the risk of accidents. Intelligent transportationsystems may contribute to mitigate such problems. LÄS MER

  4. 3. Pierced, Wrapped and Torn : Aspects of String Theory Compactifications

    Författare :Magdalena Larfors; Ulf Danielsson; Gary Shiu; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical physics; Matematisk fysik; Theoretical Physics; teoretisk fysik;

    Sammanfattning : An outstanding problem in physics is to find a unified framework for quantum mechanics and general relativity. This is required for a better understanding of black holes and the early cosmology of the universe. String theory provides such a unification. In this thesis, we study aspects of compactifications of type IIB string theory. LÄS MER

  5. 4. On Transient Communication Outages among Collaborating Connected and Automated Vehicles

    Författare :Shahriar Hasan; Elisabeth Uhlemann; Svetlana Girs; Javier Manuel Gozalvez Sempere; Mälardalens universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ACC; CACC; Communication Systems; Systems-of-systems; Fault tolerance; fail-operational; fail-safe; transient communication outages; platooning; connected and automated vehicles; V2V; V2X; emergency braking; collision avoidance; string stability; machine learning; artificial intelligence; ML AI; X-AI; communication delays; discrete-even simulations; SUMO; PLEXE; Veins; OMNeT ; PlatoonSAFE; Computer Science; datavetenskap;

    Sammanfattning : Recent advances in wireless technology facilitating Vehicle-to-Vehicle (V2V) communication have paved the way towards connected and more cooperative Intelligent Transportation Systems (ITSs), enhancing road safety and sustainability. Connected and Automated Vehicles (CAVs) can exchange information with one another and their surrounding infrastructure, thereby enabling cooperative automated maneuvering such as vehicle platooning. LÄS MER

  7. 5. Making Maps and Keeping Logs : Quantum Gravity from Classical Viewpoints

    Författare :Niklas Johansson; Ulf Danielsson; Jan de Boer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; String theory; black holes in string theory; Calabi-Yau geometry; flux compactifications; three-dimensional gravity; Mathematical physics; Matematisk fysik; Theoretical Physics; teoretisk fysik;

    Sammanfattning : This thesis explores three different aspects of quantum gravity. First we study D3-brane black holes in Calabi-Yau compactifications of type IIB string theory. Using the OSV conjecture and a relation between topological strings and matrix models we show that some black holes have a matrix model description. LÄS MER