Sökning: "invariance"

Visar resultat 6 - 10 av 90 avhandlingar innehållade ordet invariance.

1. 6. The Powers of Perturbation Theory : Loops and Gauge Invariance in Particle Physics

   Författare :Johan Löfgren; Rikard Enberg; Kimmo Kainulainen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beyond the Standard Model; Electroweak phase transition; Perturbation theory; High Energy Physics; Högenergifysik;

   Sammanfattning : The Standard Model is the best particle physics theory we have, but there are still phenomena that it cannot explain. In this thesis I have worked on two different projects that connect to two of the biggest unsolved questions of the Standard Model. LÄS MER

3. 7. Stochastic Invariance and Aperiodic Control for Uncertain Constrained Systems

   Författare :Yulong Gao; Karl H. Johansson; Alessandro Abate; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; controlled invariant set; stochastic system; constraint; uncertainty; reachable set; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Uncertainties and constraints are present in most control systems. For example, robot motion planning and building climate regulation can be modeled as uncertain constrained systems. In this thesis, we develop mathematical and computational tools to analyze and synthesize controllers for such systems. LÄS MER

4. 8. Bending, Twisting and Turning : Protein Modeling and Visualization from a Gauge-Invariance Viewpoint

   Författare :Martin Lundgren; Antti Niemi; Jørgen Ellegaard Andersen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; protein folding; discrete frenet frame; solitons; protein visualization; Physics and Astronomy specializing in Theoretical Physics; Fysik och astronomi med inriktning mot teoretisk fysik;

   Sammanfattning : Proteins in nature fold to one dominant native structure. Despite being a heavily studied field, predicting the native structure from the amino acid sequence and modeling the folding process can still be considered unsolved problems. In this thesis I present a new approach to this problem with methods borrowed from theoretical physics. LÄS MER

5. 9. Applications of Gaussian Noise Stability in Inapproximability and Social Choice Theory

   Författare :Marcus Isaksson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gaussian noise stability; inapproximability theory; invariance principle; max-q-cut; condorcet voting; max-q-cut;

   Sammanfattning : Gaussian isoperimetric results have recently played an important role in proving fundamental results in hardness of approximation in computer science and in the study of voting schemes in social choice theory. In this thesis we prove a generalization of a Gaussian isoperimetric result by Borell and show that it implies that the majority function is optimal in Condorcet voting in the sense that it maximizes the probability that there is a single candidate which the society prefers over all other candidates. LÄS MER

7. 10. On Lorentz Invariance, Regularity and Global Existence for Kinetic Equations

   Författare :Håkan Andreasson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : [A1] Regularity of the gain term and strong L1 convergence to equilibrium for the relativistic Boltzmann equation. The main purpose of the paper is to show that the gain term of the relativistic collision operator is regularizing. This is a generalization of P.L. LÄS MER