Avancerad sökning

Visar resultat 1 - 5 av 469 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Searches for Particle Dark Matter : Dark stars, dark galaxies, dark halos and global supersymmetric fits

   Författare :Pat Scott; Joakim Edsjö; Lars Bergström; Jan Conrad; Dan Hooper; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; dark matter; supersymmetry; gamma rays; dwarf galaxies; stellar evolution; cosmological perturbations; phase transitions; statistical techniques; Astroparticle physics; Astropartikelfysik; Astroparticle physics; Astropartikelfysik; Cosmology; Kosmologi; Elementary particle physics; Elementarpartikelfysik; Computational physics; Beräkningsfysik; Formation and development of stars; Stjärnors bildning och utveckling; High energy astrophysics; Högenergiastrofysik; teoretisk fysik; Theoretical Physics;

   Sammanfattning : The identity of dark matter is one of the key outstanding problems in both particle and astrophysics. In this thesis, I describe a number of complementary searches for particle dark matter. LÄS MER

3. 2. Spectral Properties of Type Ia Supernovae and Implications for Cosmology

   Författare :Jakob Nordin; Ariel Goobar; Mark Phillips; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; cosmology; spectroscopy; supernovae; Physics; Fysik; Cosmology; Kosmologi; Extragalactical astronomy; Extragalaktisk astronomi; fysik; Physics;

   Sammanfattning : Type Ia supernovae can, for a short period of time, reach the same brightness as an entire galaxy. They are responsible for the creation of a large fraction of all heavy elements and can be used, as standard candles, to prove that the expansion of the universe is accelerating. Yet, we do not fully understand them. LÄS MER

4. 3. Gravitational perturbations in plasmas and cosmology

   Författare :Mats Forsberg; Gert Brodin; Michael Bradley; Christopher Clarkson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; general relativity; cosmology; gravitational waves; plasma; electromagnetic waves; nonlinear waves; Plasma physics; Plasmafysik; Theory of relativity; gravitation; Relativitetsteori; gravitation; Cosmology; Kosmologi; teoretisk fysik; Theoretical Physics;

   Sammanfattning : Gravitational perturbations can be in the form of scalars, vectors or tensors. This thesis focuses on the evolution of scalar perturbations in cosmology, and interactions between tensor perturbations, in the form of gravitational waves, and plasma waves. LÄS MER

5. 4. Legacy fostering the twins. Connecting the S/X and VGOS telescope network generations

   Författare :Rebekka Handirk; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VLBI; Space Geodesy; VGOS; Local Ties; S X;

   Sammanfattning : With the VLBI Global Observing System (VGOS) being the next step in the development of geodetic Very Long Baseline Interferometry (VLBI), it is necessary to connect the new VGOS network to existing legacy S/X telescopes. Specially designed short-baseline interferometry sessions aim to obtain local-tie vectors between these telescope generations at observatories that have both legacy S/X and new generation VGOS telescopes. LÄS MER

7. 5. Direct Write Technology of SIN Tunnel Junctions for Thermometry and Microwave Devices

   Författare :Ernst Otto; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; Cold-Electron Bolometer; direct write technology; SIN tunnel junction;

   Sammanfattning : This thesis concerns development of SIN junction technology for thermometry and microwave detectors, as well as technology of a planar phase switch as a part of integratedmicrowave receiver.Cold-Electron Bolometer (CEB) is a sensitive detector of a microwave radiation, in which SIN tunnel junctions are used for temperature measurement of a nanoscale absorber in thesame way as in SIN thermometers. LÄS MER