Avancerad sökning

Visar resultat 1 - 5 av 11 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Modelling and analyzing strong-field effects in quantum plasma

   Författare :Haidar Al-Naseri; Gert Brodin; Jens Zamanian; J. Tito Mendonca; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasma physics; Strong-field physics; Kinetic theory; Quantum plasma; fysik; Physics;

   Sammanfattning : Under the extreme conditions that can be found around dense stars and in the accretion discs of black holes, several strong-field quantum phenomena dominate the dynamics of the plasma. This includes the creation of matter and anti-matter from the vacuum (Schwinger mechanism), radiation reaction and Landau quantization. LÄS MER

3. 2. Low-energy ions around comet 67P/Churyumov-Gerasimenko

   Författare :Sofia Bergman; Gabriella Stenberg Wieser; Martin Wieser; Gert Brodin; Stein Håland; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Low-energy ions; spacecraft charging; comets; 67P Churyumov-Gerasimenko; Rosetta; RPC-ICA; SPIS; diamagnetic cavity; field of view; plasma; space plasma physics; rymd- och plasmafysik; Space and Plasma Physics;

   Sammanfattning : Low-energy ions play important roles in the formation of the plasma environment around a comet. Reliable ways of measuring these ions are therefore of high importance to fully understand the processes and dynamics of this environment. Unfortunately, low-energy ions are infamously difficult to detect. LÄS MER

4. 3. The effect of spacecraft charging on low-energy ion measurements around comet 67P/Churyumov-Gerasimenko

   Författare :Sofia Bergman; Gabriella Stenberg Wieser; Martin Wieser; Gert Brodin; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spacecraft charging; low-energy ions; space physics; plasma physics; comet; Rosetta; SPIS; rymd- och plasmafysik; Space and Plasma Physics;

   Sammanfattning : A spacecraft in space interacts with the surrounding environment and aqcuires an electrostatic potential. Charged particles are constantly bombarding the surface of the spacecraft, and at the same time solar EUV radiation induces photoemission, causing electrons to be emitted from the surface. LÄS MER

5. 4. Quantum Kinetic Theory for Plasmas : spin, exchange, and particle dispersive effects

   Författare :Robin Ekman; Gert Brodin; Jens Zamanian; Bengt Eliasson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; teoretisk fysik; Theoretical Physics;

   Sammanfattning : This thesis is about developing and studying quantum mechanical models of plasmas. Quantum effects can be important at high densities, at low temperatures, and in strong electromagnetic fields, in various laboratory and astrophysical systems. LÄS MER

7. 5. Perturbative Methods in General Relativity

   Författare :Daniel Eriksson; Michael Bradley; Gert Brodin; Lászlo Árpád Gergely; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; General relativity; perturbation theory; photon-photon scattering; cosmology; FRW models with cosmological constant; Bianchi type V; slowly rotating stars; Hartle formalism; Physics; Fysik;

   Sammanfattning : Einstein's theory of general relativity is a cornerstone in the process of gaining increased understanding about problems of gravitational nature. It can be applied to problems on the huge length scales of cosmology and as far as we know it does not break down before the Planck scale is approached. LÄS MER