Sökning: "modifications of gravity"

Hittade 5 avhandlingar innehållade orden modifications of gravity.

  1. 1. Regional Geoid Determination Methods for the Era of Satellite Gravimetry : Numerical Investigations Using Synthetic Earth Gravity Models

    Författare :Jonas Ågren; Lars E. Sjöberg; Zdenek Martince; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; geoid determination; GOCE; synthetic earth gravity models; kernel modification; downward continuation; Geovetenskap; Earth sciences; Geovetenskap;

    Sammanfattning : It is the purpose of this thesis to investigate different regional geoid determination methods with respect to their feasibility for use with a future GOCE satellite-only Earth Gravity Model (EGM). This includes investigations of various techniques, which involve different approximations, as well as the expected accuracy. LÄS MER

  3. 2. Cosmoparticle Physics and String Theory

    Författare :Stefan Sjörs; Marcus Berg; Joseph Conlon; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Supersymmetry; dark matter; cosmology; inflation; modifications of gravity; string theory; flux compactifications; perturbative string theory; teoretisk fysik; Theoretical Physics;

    Sammanfattning : This thesis deals with phenomenological and theoretical aspects of cosmoparticle physics and string theory. There are many open questions in these topics. In connection with cosmology we would like to understand the detailed properties of dark matter, dark energy, generation of primordial perturbations, etc. LÄS MER

  4. 3. Settling Mechanisms of Valuable Metal Droplets in Iron Silicate Slag

    Författare :Jenny Isaksson; Caisa Samuelsson; Andreas Lennartsson; Anton Andersson; Ari Jokilaakso; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Process Metallurgy; Processmetallurgi;

    Sammanfattning : A significant source of copper losses from pyrometallurgical copper extraction is attributed to dissolved and entrained copper in discarded slag. Entrained copper can be recovered via pyrometallurgical slag cleaning in a settling furnace where the droplets settle under gravity. LÄS MER

  5. 4. Buildings and district heating - contributions to development and assessments of efficient technology

    Författare :Per-Olof Johansson; Energihushållning; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; District heating; hydronic space heating; natural circulation; lowered return temperature; primary energy; add-on-fan blower;

    Sammanfattning : The objective of this thesis is to contribute to improved performance of district heating systems by focusing on three items. Item 1: Study of three methods for improving the performance of sub-systems within buildings connected to the distribution network. The methods can be considered as more or less innovative. LÄS MER

  7. 5. Consistent Nonlinear Interactions for the Graviton

    Författare :Angnis Schmidt-May; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis investigates various aspects of massive gravity and bimetric gravity which be- long to a certain class of modifications of general relativity. It provides an introduction to linear massive gravity in flat backgrounds, before reviewing the construction of consistent nonlinear massive gravity that avoids the Boulware-Deser ghost instability. LÄS MER