Sökning: "Vetenskaplig artikel geometri"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden Vetenskaplig artikel geometri.

  1. 1. Strong Cosmic Censorship and Cosmic No-Hair in spacetimes with symmetries

    Författare :Katharina Maria Radermacher; Hans Ringström; James Isenberg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Cosmic Censorship; Cosmic No-Hair; Big Bang; symmetry; Bianchi; T2-symmetry; Gowdy; general relativity; cosmology; late time; initial time; asymptotic behaviour; perfect fluid; scalar field; Einstein equations; Mathematics; Matematik;

    Sammanfattning : This thesis consists of three articles investigating the asymptotic behaviour of cosmological spacetimes with symmetries arising in Mathematical General Relativity.In Paper A and B, we consider spacetimes with Bianchi symmetry and where the matter model is that of a perfect fluid. LÄS MER

  3. 2. On the breakdown of regularity of invariant curves in quasi-periodically forced systems

    Författare :Thomas Ohlson Timoudas; Kristian Bjerklöv; Joaquim Puig; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dynamical systems; strange attractors; Schrödinger cocycles;

    Sammanfattning : In this thesis we study the process of torus collisions in one-parameter families of quasi-periodically forced dynamical systems. Specifically, we study the process whereby two invariant curves (homeomorphic to circles), one attracting and one repelling, bifurcate into a strange non-chaotic attractor. LÄS MER

  4. 3. Topics in Combinatorial Algebraic Geometry

    Författare :Anders Lundman; Sandra Di Rocco; Giorgio Ottaviani; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Sammanfattning : This thesis consists of six papers in algebraic geometry –all of which have close connections to combinatorics. In Paper A we consider complete smooth toric embeddings X ↪ P^N such that for a fixed positive integer k the t-th osculating space at every point has maximal dimension if and only if t ≤ k. LÄS MER

  5. 4. Abdominal aortic aneurysm inception and evolution - A computational model

    Författare :Andrii Grytsan; T. Christian Gasser; Martin Kroon; Frans N. van de Vosse; KTH; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aorta; Aneurysm; AAA; Blood Flow; Wall Shear Stress; Growth and Remodeling; Mixture Model; Growth Kinematics; Fluid-Solid-Growth; Aorta; Aneurysm; AAA; Blodflöde; Vägg Skjuvspänning; Tillväxt och Strukturförändring; Blandning Modell; Tillväxt Kinematik; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : Abdominal aortic aneurysm (AAA) is characterized by a bulge in the abdominal aorta. AAA development is mostly asymptomatic, but such a bulge may suddenly rupture, which is associated with a high mortality rate. Unfortunately, there is no medication that can prevent AAA from expanding or rupturing. LÄS MER

  7. 5. Topics in projective algebraic optimization

    Författare :Lukas Gustafsson; Sandra Di Rocco; Kathlén Kohn; Cordian Riener; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis explores optimization challenges within algebraic statistics, employing both topological and geometrical methodologies to derive new insights. The main focus is the optimization degree of nearest point and Gaussian maximum likelihood estimation problems with algebraic constraints. LÄS MER