Browsing Institutt for teoretisk astrofysikk by Title
Now showing items 420-439 of 1279
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)The Euclid mission – with its spectroscopic galaxy survey covering a sky area over 15 000 deg 2 in the redshift range 0.9 < z < 1.8 – will provide a sample of tens of thousands of cosmic voids. This paper thoroughly ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)We have investigated the cosmological constraints that can be expected from measurement of the cross-correlation of galaxies with cosmic voids identified in the Euclid spectroscopic survey, which will include spectroscopic ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)An accurate covariance matrix is essential for obtaining reliable cosmological results when using a Gaussian likelihood. In this paper we study the covariance of pseudo- C ℓ estimates of tomographic cosmic shear power ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)Aims. We investigate the contribution of shot-noise and sample variance to uncertainties in the cosmological parameter constraints inferred from cluster number counts, in the context of the Euclid survey. Methods. By ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)We present a method for fast evaluation of the covariance matrix for a two-point galaxy correlation function (2PCF) measured with the Landy–Szalay estimator. The standard way of evaluating the covariance matrix consists ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)Context. The standard cosmological model is based on the fundamental assumptions of a spatially homogeneous and isotropic universe on large scales. An observational detection of a violation of these assumptions at any ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)Context. In metric theories of gravity with photon number conservation, the luminosity and angular diameter distances are related via the Etherington relation, also known as the distance duality relation (DDR). A violation ...
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(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)Modelling uncertainties at small scales, i.e. high k in the power spectrum P(k), due to baryonic feedback, nonlinear structure growth and the fact that galaxies are biased tracers poses a significant obstacle to fully ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)Euclid is poised to survey galaxies across a cosmological volume of unprecedented size, providing observations of more than a billion objects distributed over a third of the full sky. Approximately 20 million of these ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)The Euclid space telescope will survey a large dataset of cosmic voids traced by dense samples of galaxies. In this work we estimate its expected performance when exploiting angular photometric void clustering, galaxy weak ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)The material composition of asteroids is an essential piece of knowledge in the quest to understand the formation and evolution of the Solar System. Visual to near-infrared spectra or multiband photometry is required to ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)Context. The ESA Euclid space telescope could observe up to 150 000 asteroids as a side product of its primary cosmological mission. Asteroids appear as trailed sources, that is streaks, in the images. Owing to the survey ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2024)To obtain an accurate cosmological inference from upcoming weak lensing surveys such as the one conducted by Euclid , the shear measurement requires calibration using galaxy image simulations. As it typically requires ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)The measurement of the absolute neutrino mass scale from cosmological large-scale clustering data is one of the key science goals of the Euclid mission. Such a measurement relies on precise modelling of the impact of ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)Context. Future weak lensing surveys, such as the Euclid mission, will attempt to measure the shapes of billions of galaxies in order to derive cosmological information. These surveys will attain very low levels of statistical ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)Weak lensing, which is the deflection of light by matter along the line of sight, has proven to be an efficient method for constraining models of structure formation and reveal the nature of dark energy. So far, most ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)Pair-instability supernovae are theorized supernovae that have not yet been observationally confirmed. They are predicted to exist in low-metallicity environments. Because overall metallicity becomes lower at higher ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)Context. The Copernican principle, the notion that we are not at a special location in the Universe, is one of the cornerstones of modern cosmology. Its violation would invalidate the Friedmann-Lemaître-Robertson-Walker ...
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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)Context. The data from the Euclid mission will enable the measurement of the angular positions and weak lensing shapes of over a billion galaxies, with their photometric redshifts obtained together with ground-based ...
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Euclid: The reduced shear approximation and magnification bias for Stage IV cosmic shear experiments (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)Context. Stage IV weak lensing experiments will offer more than an order of magnitude leap in precision. We must therefore ensure that our analyses remain accurate in this new era. Accordingly, previously ignored systematic ...