Browsing Institutt for teoretisk astrofysikk by Title

Now showing items 296-315 of 1274

  • Dark energy survey year 3 results: weak lensing shape catalogue 
    Gatti, Marco; Sheldon, Erin; Amon, A.; Becker, M.; Troxel, M. A.; Choi, A.; Doux, Cyrille; MacCrann, Niall; Navarro-Alsina, A.; Harrison, Ian; Gruen, Daniel; Bernstein, G.; Jarvis, M.; Secco, Lucas Frozza; Ferté, Agnès; Shin, T.; McCullough, J.; Rollins, R. P.; Chen, R.; Chang, Chihway L.; Pandey, S.; Tutusaus, I.; Prat, Judit; Elvin-Poole, J.; Sánchez, C.; Plazas, Andrés A.; Roodman, A.; Zuntz, Joseph; Abbott, T. M. C.; Aguena, Michel; Allam, S.; Annis, J.; Avila, S.; Bacon, D.; Bertin, E.; Bhargava, S.; Brooks, D.; Burke, David L.; Carnero Rosell, Aurelio; Carrasco Kind, Matias; Carretero, J.; Castander, F. J.; Conselice, C.; Costanzi, M.; Crocce, M.; da Costa, L. N.; Davis, Tamara M.; De Vicente, J.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Drlica-Wagner, Alex; Eckert, K.; Everett, S.; Ferrero, Ismael; Frieman, J.; García-Bellido, Juan; Gerdes, David W.; Giannantonio, Tommaso; Gruendl, Robert A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Hinton, Samuel R.; Hollowood, Devon L.; Honscheid, Klaus; Hoyle, B.; Huff, Eric M.; Huterer, Dragan; Jain, Bhuvnesh; James, D. J.; Jeltema, T.; Krause, E.; Kron, R.; Kuropatkin, Nikolay; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Miquel, R.; Morgan, R.; Myles, Justin; Palmese, Antonella; Paz-Chinchón, Francisco; Rykoff, Eli S.; Samuroff, S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, Ignacio; Smith, M.; Soares-Santos, Marcelle; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; To, Chun-Hao; Tucker, D. L.; Varga, T. N.; Wechsler, Risa H.; Weller, Jochen; Wester, W.; Wilkinson, R. D. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    ABSTRACT We present and characterize the galaxy shape catalogue from the first 3 yr of Dark Energy Survey (DES) observations, over an effective area of  4143 deg2 of the southern sky. We describe our data analysis ...
  • Dark energy with an Anisotropic Equation of State 
    Lee, Eunseong (Master thesis / Masteroppgave, 2013)
    We investigate cosmologies where the accelerated expansion of the universe is driven by a fluid with an anisotropic equation of state. If dark energy equation of state is anisotropic, the expansion rate of the universe ...
  • Dark matter candidate from torsion 
    de la Cruz Dombriz, Álvaro; Maldonado Torralba, Francisco José; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    The stable pseudo-scalar degree of freedom of the quadratic Poincaré Gauge theory of gravity is shown to be a suitable dark matter candidate. We find the parameter space of the theory which can account for all the predicted ...
  • Dark matter haloes in modified gravity and dark energy: interaction rate, small- and large-scale alignment 
    L'Huillier, Benjamin; Winther, Hans Arnold; Mota, David; Park, Changbom; Kim, Juhan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We study the properties of dark matter haloes in a wide range of modified gravity models, namely, f(R), DGP and interacting dark energy models. We study the effects of modified gravity and dark energy on the internal ...
  • Data Analysis and Systematic Error Mitigation in the COMAP Experiment 
    Stutzer, Nils-Ole (Master thesis / Masteroppgave, 2021)
    Although modern cosmology has been able to reveal a wealth of information about the Universe, there are still many questions to be answered, such as the details of how the first stars ionized the Universe in the Epoch of ...
  • Data selection for intensity mapping experiments using machine learning 
    Rasmussen, Maren (Master thesis / Masteroppgave, 2020)
    The CO Mapping Array Pathfinder (COMAP) experiment is an intensity mapping experiment, currently in an early stage where learning how to process the data is one of the top points on the priority list. This includes the ...
  • Dawn of the dark: unified dark sectors and the EDGES Cosmic Dawn 21-cm signal 
    Yang, Weiqiang; Pan, Supriya; Vagnozzi, Sunny; Di Valentino, Eleonora; Mota, David; Capozziello, Salvatore (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
    While the origin and composition of dark matter and dark energy remains unknown, it is possible that they might represent two manifestations of a single entity, as occurring in unified dark sector models. On the other hand, ...
  • DBI Galileons in the Einstein frame: Local gravity and cosmology 
    Zumalacárregui, Miguel; Koivisto, Tomi Sebastian; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    It is shown that a disformally coupled theory in which the gravitational sector has the Einstein-Hilbert form is equivalent to a quartic Dirac-Born-Infeld Galileon Lagrangian, possessing nonlinear higher derivative ...
  • DEATHSTAR: nearby AGB stars with the Atacama Compact Array. II. CO envelope sizes and asymmetries: the S-type stars 
    Andriantsaralaza, Miora; Ramstedt, S.; Vlemmings, W. H. T.; Danilovich, T.; De Beck, E.; Groenewegen, M.; Höfner, S.; Kerschbaum, F.; Khouri, T.; Lindqvist, M.; Maercker, M.; Olofsson, H.; Quintana-Lacaci, G.; Saberi, Maryam; Sahai, R.; Zijlstra, A. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Aims. We aim to constrain the sizes of, and investigate deviations from spherical symmetry in, the CO circumstellar envelopes (CSEs) of 16 S-type stars, along with an additional 7 and 4 CSEs of C-type and M-type AGB stars, ...
  • Deciphering Solar Coronal Heating: Energizing Small-scale Loops through Surface Convection 
    Nóbrega Siverio, Daniel Elias; Moreno-Insertis, F.; Galsgaard, K.; Krikova, Kilian; Rouppe van der Voort, Luc; Joshi, Reetika; Madjarska, M.S. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract The solar atmosphere is filled with clusters of hot small-scale loops commonly known as coronal bright points (CBPs). These ubiquitous structures stand out in the Sun by their strong X-ray and/or ...
  • Deciphering the Slow-rise Precursor of a Major Coronal Mass Ejection 
    Cheng, X.; Xing, C.; Aulanier, Guillaume; Solanki, S.K.; Peter, H.; Ding, M.D. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract Coronal mass ejections are explosive plasma phenomena prevalently occurring on the Sun and probably on other magnetically active stars. However, how their pre-eruptive configuration evolves toward the ...
  • Deep solar ALMA neural network estimator for image refinement and estimates of small-scale dynamics 
    Eklund, Henrik (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Context. The solar atmosphere is highly dynamic, and observing the small-scale features is valuable for interpretations of the underlying physical processes. The contrasts and magnitude of the observable signatures of ...
  • DeepZipper. II. Searching for Lensed Supernovae in Dark Energy Survey Data with Deep Learning 
    Morgan, R.; Nord, B.; Bechtol, K.; Möller, A.; Hartley, W. G.; Birrer, S.; González, S.J.; Martinez, M.; Gruendl, R.A.; Buckley-Geer, E.J.; Shajib, A.J.; Carnero Rosell, Aurelio; Lidman, C.; Collett, T.; Abbott, Timothy M. C.; Aguena, M.; Andrade-Oliveira, F.; Annis, J.; Bacon, D.; Bocquet, S.; Brooks, D.; Burke, D. L.; Carrasco Kind, Matias; Carretero, J.; Castander, Francisco Javier; Conselice, C.; da Costa, Luiz N.; Costanzi, M.; De Vicente, J.; Desai, S.; Doel, P.; Everett, S.; Ferrero, Ismael; Flaugher, B.; Friedel, D.; Frieman, J.; García-Bellido, J.; Gaztañaga, E.; Gruen, D.; Gutierrez, G.; Hinton, S. R.; Hollowood, D.L.; Honscheid, K.; Kuehn, K.; Kuropatkin, N.; Lahav, Ofer; Lima, M.; Menanteau, F.; Miquel, R.; Palmese, A.; Paz-Chinchón, F.; Pereira, M.E.S.; Pieres, A.; Plazas Malagón, Andrés A.; Prat, J.; Rodriguez-Monroy, M.; Romer, A. K.; Roodman, A.; Sánchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Smith, M.; Suchyta, E.; Swanson, Molly E. C.; Tarlé, Gregory; Thomas, D.; Varga, Tamas Norbert (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract Gravitationally lensed supernovae (LSNe) are important probes of cosmic expansion, but they remain rare and difficult to find. Current cosmic surveys likely contain 5–10 LSNe in total while next-generation ...
  • DeepZipper: A Novel Deep-learning Architecture for Lensed Supernovae Identification 
    Morgan, R.; Nord, B.; Bechtol, K.; González, S.J.; Buckley-Geer, E.; Möller, A.; Park, J.W.; Kim, A.G.; Birrer, S.; Aguena, M.; Annis, J.; Bocquet, S.; Brooks, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cawthon, R.; Da Costa, L.N.; Davis, T.M.; De Vicente, J.; Doel, P.; Ferrero, Ismael; Friedel, D.; Frieman, J.; García-Bellido, J.; Gatti, M.; Gaztanaga, E.; Giannini, G.; Gruen, D.; Gruendl, R.A.; Gutierrez, G.; Hollowood, D.L.; Honscheid, K.; James, D.J.; Kuehn, K.; Kuropatkin, N.; Maia, M.A.G.; Miquel, R.; Palmese, A.; Paz-Chinchón, F.; Pereira, M.E.S.; Pieres, A.; Plazas Malagón, A.A.; Reil, K.; Roodman, A.; Sanchez, E.; Smith, M.; Suchyta, E.; Swanson, M.E.C.; Tarle, G.; To, C. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Large-scale astronomical surveys have the potential to capture data on large numbers of strongly gravitationally lensed supernovae (LSNe). To facilitate timely analysis and spectroscopic follow-up before the supernova ...
  • Degeneracies between Modified Gravity and Baryonic PhysicsRestricted Access 
    Ellewsen, Thor Andreas Seiff (Master thesis / Masteroppgave, 2017)
    In order to determine the observable signatures of modified gravity theories, it is important to consider the effect of baryonic physics. We use a modified version of the ISIS code to run cosmological hydrodynamic simulations ...
  • Degeneracies between modified gravity and baryonic physics 
    Seiff Ellewsen, Thor Andreas; Falck, Bridget Lynn; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    In order to determine the observable signatures of modified gravity theories, it is important to consider the effect of baryonic physics. We used a modified version of the ISIS code to run cosmological hydrodynamic simulations ...
  • Demonstration of Magnetic Field Tomography with Starlight Polarization toward a Diffuse Sightline of the ISM 
    Panopoulou, Georgia V.; Tassis, Konstantinos; Skalidis, Raphael; Blinov, Dmitriy; Liodakis, Ioannis; Pavlidou, Vasiliki; Potter, Stephen B.; Ramaprakash, Anamparambu N.; Readhead, Anthony C. S.; Wehus, Ingunn Kathrine (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The availability of large data sets with stellar distance and polarization information will enable a tomographic reconstruction of the (plane-of-the-sky-projected) interstellar magnetic field in the near future. We demonstrate ...
  • The density profile of clusters of galaxies : Abell 1351 & Abell 1995 
    Holhjem, Karianne (Master thesis / Masteroppgave, 2006)
    Two galaxy clusters, Abell 1351 and Abell 1995, are examined using weak gravitational lensing techniques. Mass maps are created, and the clusters' density and shear profiles are compared to theoretical predictions. Gravitational ...
  • Density-dependent clustering - I. Pulling back the curtains on motions of the BAO peak 
    Neyrinck, Mark; Szapudi, Istvan; McCullagh, N.; Szalay, Alexander S; Falck, Bridget Lynn; Wang, Jie (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The most common statistic used to analyse large-scale structure surveys is the correlation function, or power spectrum. Here, we show how ‘slicing’ the correlation function on local density brings sensitivity to interesting ...
  • Depicting a Black Hole Merger: A Bridge Between Einstein Toolkit and GYOTO 
    Heinesen, Daniel (Master thesis / Masteroppgave, 2021)
    In this project we create a conversion tool for using numerical general relativity simulations done in Einstein Toolkit in the numerical relativity ray tracer tool General relativitY Orbit Tracer of Observatoire de ...