Now showing items 247-266 of 517

  • Li, Baojiu; Mota, David; Barrow, J. D. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2011)
    We introduce the N-body simulation technique to follow structure formation in linear and nonlinear regimes for the extended quintessence models (scalar-tensor theories in which the scalar field has a self-interaction ...
  • Opheimsbakken, Håkon (Master thesis / Masteroppgave, 2014)
    Neutrinos are very weakly interacting particles with a low mass. In fact, the mass of the neutrinos has not yet been determined by experiments or observations. Still, neutrinos are a good candidate for some of the dark ...
  • Garay, Carlos Peña; Verde, Licia; Jimenez, Raul (Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)
    Recent constrains on the sum of neutrino masses inferred by analyzing cosmological data, show that detecting a non-zero neutrino mass is within reach of forthcoming cosmological surveys. Such a measurement will imply a ...
  • Jenssen, Espen Sem (Master thesis / Masteroppgave, 2016)
    The universe is full of stuff we cannot see, neither directly or indirectly. We do not understand the nature of the mysterious dark matter and how it interacts with normal matter. Big Bang Nucleosynthesis (BBN) provides ...
  • Ovaldsen, Jan-Erik (Master thesis / Hovedoppgave, 2002)
    Five years (1992-1997, ~2650 images) of optical observations of the gravitational lens system QSO 0957+561 were analyzed using a new photometry package developed by Jan Teuber and me. My supervisor was Prof. Rolf Stabell, ...
  • Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, Adri J.; Eriksen, Hans Kristian Kamfjord; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, Anne E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, Lorenzo; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, Benjamin; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, Tone Melvær; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; Van der List, J. F.; Weber, A. C.; Wehus, Ingunn Kathrine; Wiebe, D. V.; Young, E. Y. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017. The American Astronomical Society. All rights reserved.
  • Kakiichi, Koki; Dijkstra, Mark (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present a new perturbative approach to ‘constrained Ly α radiative transfer’ (RT) through the circum- and intergalactic medium (CGM and IGM). We constrain the H I content and kinematics of the CGM and IGM in a physically ...
  • Golding, Thomas Peter; Leenaarts, Jorrit; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    The ionization state of the gas in the dynamic solar chromosphere can depart strongly from the instantaneous statistical equilibrium commonly assumed in numerical modeling. We improve on earlier simulations of the solar ...
  • Golding, Thomas Peter (Doctoral thesis / Doktoravhandling, 2017)
  • Rudjord, Øystein (Doctoral thesis / Doktoravhandling, 2010)
  • hong, Jie; Ding, M. D.; Li, Ying; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The Fe i 6173 Å line is widely used in the measurements of vector magnetic fields by instruments including the Helioseismic and Magnetic Imager (HMI). We perform non-local thermodynamic equilibrium calculations of this ...
  • Lind, K.; Amarsi, A. M.; Asplund, M.; Barklem, P. S.; Bautista, M.; Bergemann, M.; Collet, R.; Kiselman, D.; Leenaarts, Jorrit; Mendes Domingos Pereira, Tiago (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Our ability to model the shapes and strengths of iron lines in the solar spectrum is a critical test of the accuracy of the solar iron abundance, which sets the absolute zero-point of all stellar metallicities. We use an ...
  • Tayfeh, Bagheri F. (Master thesis / Masteroppgave, 2013)
    The existence of dark energy in the universe is hypothesized to explain the accelerated expansion of today’s universe and the inflationary expansion of very early universe; accelerated expansion of today’s universe is ...
  • Bakke, Helle; Frogner, Lars; Gudiksen, Boris Vilhelm (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Context: We introduce a model for including accelerated particles in pure magnetohydrodynamics (MHD) simulations of the solar atmosphere. Aims: We show that the method is viable and produces results that enhance the realism ...
  • Olluri, Kosovare (Doctoral thesis / Doktoravhandling, 2014)
    De siste par tiårene har avanserte forskningssatellitter og rombaserte observatorier gitt oss innsikt i en svært dynamisk solatmosfære, hvor lokale variable som temperatur og tetthet endres på korte tidsskalaer. Disse ...
  • Yang, Weiqiang; Pan, Supriya; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017 American Physical Society
  • Riemer-Sørensen, Signe; Jenssen, Espen Sem (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
  • Frogner, Lars (Master thesis / Masteroppgave, 2018)
    Solar flares play a key role in the dynamics of the solar atmosphere. They occur with a wide range of energies, from the largest X-class flares representing some of the most violent releases of energy in the solar system, ...
  • Bjørgen, Johan Pires (Master thesis / Masteroppgave, 2014)
    Solving the non-LTE radiative transfer problem in stellar atmospheres is computationally demanding. There is therefore an interest to investigate new methods to solve this problem effectively. A numerical method, multigrid, ...
  • Hansteen, Viggo; Guerreiro, Nuno Miguel Rodrigues; De Pontieu, Bart Walter; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Advanced three-dimensional (3D) radiative MHD simulations now reproduce many properties of the outer solar atmosphere. When including a domain from the convection zone into the corona, a hot chromosphere and corona are ...