Search for dissertations about: "Metric Space"

Showing result 1 - 5 of 53 swedish dissertations containing the words Metric Space.

  1. 1. Space Plasma Dynamics : Instabilities, Coherent Vortices and Covariant Parametrization

    Author : David Sundkvist; Jan-Erik Wahlund; Andris Vaivads; Stuart Bale; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma; instabilities; turbulence; coherent structures; vortex; self-organization; magnetosphere; waves; electromagnetism; covariant; space instrumentation; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Abstract : The magnetospheric cusps are two funnel-like regions of Earth's magnetosphere where solar wind plasma can have direct access to the ionosphere. The cusps are very dynamic regions where wave-particle interactions continuously take place and redistribute energy among different particle populations. READ MORE

  2. 2. Sobolev-Type Spaces : Properties of Newtonian Functions Based on Quasi-Banach Function Lattices in Metric Spaces

    Author : Lukáš Malý; Anders Björn; Jana Björn; Tomas Sjödin; Andrea Cianchi; Linköpings universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Newtonian space; Sobolev-type space; metric measure space; upper gradient; Sobolev capacity; Banach function lattice; quasi-normed space; rearrangement-invariant space; maximal operator; Lipschitz function; regularization; weak boundedness; density of Lipschitz functions; quasi-continuity; continuity; doubling measure; Poincaré inequality;

    Abstract : This thesis consists of four papers and focuses on function spaces related to first-order analysis in abstract metric measure spaces. The classical (i.e., Sobolev) theory in Euclidean spaces makes use of summability of distributional gradients, whose definition depends on the linear structure of Rn. READ MORE

  3. 3. The Double Obstacle Problem on Metric Spaces

    Author : Zohra Farnana; Jan Björn; Anders Björn; Juha Kinnunen; Jana Björn; Jan Malý; Linköpings universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; metric space; nonlinear; obstacle problem; p-harmonic; potential theory; regularity; stability; MATHEMATICS; MATEMATIK;

    Abstract : During the last decade, potential theory and p-harmonic functions have been developed in the setting of doubling metric measure spaces supporting a p-Poincar´e inequality. This theory unifies, and has applications in several areas of analysis, such as weighted Sobolev spaces, calculus on Riemannian manifolds and Carnot groups, subelliptic differential operators and potential theory on graphs. READ MORE

  4. 4. Newtonian Spaces Based on Quasi-Banach Function Lattices

    Author : Lukáš Malý; Anders Björn; Jana Björn; Tomas Sjödin; Pekka Koskela; Linköpings universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Newtonian space; upper gradient; weak upper gradient; Banach function lattice; quasi-normed space; metric measure space;

    Abstract : The traditional first-order analysis in Euclidean spaces relies on the Sobolev spaces W1,p(Ω), where Ω ⊂ Rn is open and p ∈ [1, ∞].The Sobolev norm is then defined as the sum of Lp norms of a function and its distributional gradient.We generalize the notion of Sobolev spaces in two different ways. READ MORE

  5. 5. Optimal and Hereditarily Optimal Realizations of Metric Spaces

    Author : Alice Lesser; Svante Janson; Lars-Erik Persson; Anders Johansson; Vincent Moulton; Pierre Flener; Charles Semple; Uppsala universitet; []
    Keywords : Applied mathematics; optimal realization; hereditarily optimal realization; tight span; phylogenetic network; Buneman graph; split decomposition; T-theory; finite metric space; topological graph theory; discrete geometry; Tillämpad matematik;

    Abstract : This PhD thesis, consisting of an introduction, four papers, and some supplementary results, studies the problem of finding an optimal realization of a given finite metric space: a weighted graph which preserves the metric's distances and has minimal total edge weight. This problem is known to be NP-hard, and solutions are not necessarily unique. READ MORE