Browsing Faculty of Natural Sciences by Title
Now showing items 396-415 of 2567
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Consequences of using a smooth cosmic distance in a lumpy Universe. I.
(American Physical Society, 2022)How do we appropriately fit a model based on an idealised Friedmann-Lemaˆıtre Robertson-Walker spacetime to observations made from a single location in a lumpy Universe? We address this question for surveys that measure ... -
The conservation status and population decline of the African penguin deconstructed in space and time
(Wiley-Blackwell, 2020)Understanding changes in abundance is crucial for conservation, but population growth rates often vary over space and time. We use 40 years of count data (1979–2019) and Bayesian state-space models to assess the African ... -
Conservation status and threats for African reptiles
(Elsevier, 2016)The assimilation of information on taxonomy, distribution, basic ecology and conservation status of Africa's reptiles lags far behind that for most other continents. Many regions of mainland Africa are rarely surveyed, ... -
Conservation status of large branchiopods in the Western Cape, South Africa
(Springer Verlag, 2007)Temporary wetlands are an ecologically and economically important habitat in South Africa. They harbor large branchiopods, known to be flagship species of nonpermanent aquatic habitats, and sensitive to land use changes. ... -
Considerations for optimizing the photometric classification of supernovae from the Rubin observatory
(IOP Publishing, 2022)The Vera C. Rubin Observatory will increase the number of observed supernovae (SNe) by an order of magnitude; however, it is impossible to spectroscopically confirm the class for all SNe discovered. Thus, photometric ... -
Constraining primordial non-Gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
(Institute for Ionics, 2023)Surveys of the matter distribution contain ‘fossil’ information on possible non-Gaussianity that is generated in the primordial universe. This primordial signal survives only on the largest scales where cosmic variance ... -
Constraining primordial non-gaussianity by combining next-generation galaxy and 21 cm intensity mapping surveys
(SpringerOpen, 2023)Surveys of the matter distribution contain ‘fossil’ information on possible non-Gaussianity that is generated in the primordialUniverse. This primordial signal survives only on the largest scales where cosmic variance ... -
Constraining the astrophysics and cosmology from 21 cm tomography using deep learning with the SKA
(Oxford University Press, 2020)Future Square Kilometre Array (SKA) surveys are expected to generate huge data sets of 21 cm maps on cosmological scales from the Epoch of Reionization. We assess the viability of exploiting machine learning techniques, ... -
Constraining the bright-end of the UV luminosity function for z ~ 7-9 galaxies: results from CANDELS/GOODS-South
(OUP, 2013)The recent Hubble Space Telescope near-infrared imaging with the Wide-Field Camera #3 (WFC3) of the GOODS-South field in the CANDELS program covering nearly 100 arcmin2, along with already existing Advanced Camera for ... -
Constraining the growth rate by combining multiple future surveys
(IOP Publishing, 2020)The growth rate of large-scale structure provides a powerful consistency test of the standard cosmological model and a probe of possible deviations from general relativity. We use a Fisher analysis to forecast constraints ... -
Constraining the intergalactic medium at z ≈ 9.1 using LOFAR Epoch of Reionization observations
(Advance access publications, 2020)We derive constraints on the thermal and ionization states of the intergalactic medium (IGM) at redshift ≈ 9.1 using new upper limits on the 21-cm power spectrum measured by the LOFAR radio telescope and a prior on the ... -
Constraining the magnetic field geometry of the millisecond pulsar psrj0030+0451 from joint radio, thermal x-ray, and γ-ray emission
(EDP Sciences, 2023)Context. With the advent of multi-wavelength electromagnetic observations of neutron stars - spanning many decades in photon energies - from radio wavelengths up to X-rays and γ-rays, it has become possible to significantly ... -
Constraining the neutrino mass using a multitracer combination of two galaxy surveys and cosmic microwave background lensing
(Oxford University Press, 2022)Measuring the total neutrino mass is one of the most exciting opportunities available with next-generation cosmological data sets. We study the possibility of detecting the total neutrino mass using large-scale clustering ... -
Constraining the reionization history using deep learning from 21-cm tomography with the Square Kilometre Array
(Oxford University Press, 2020)Upcoming 21-cm surveys with the SKA1-LOW telescope will enable imaging of the neutral hydrogen distribution on cosmological scales in the early Universe. These surveys are expected to generate huge imaging data sets that ... -
Constraints on anisotropic cosmic expansion from supernovae
(Edp Sciences, 2013)AIMS. We test the isotropy of the expansion of the Universe by estimating the hemispherical anisotropy of supernova type Ia (SN Ia) Hubble diagrams at low redshifts (z < 0.2). METHODS. We compare the best fit Hubble ... -
Contaminants of emerging concern (cecs) and male reproductive health: Challenging the future with a double-edged sword
(MDPI, 2023)Approximately 9% of couples are infertile, with half of these cases relating to male factors. While many cases of male infertility are associated with genetic and lifestyle factors, approximately 30% of cases are still ... -
Contemporaneous opening of the Alpine Tethys in the Eastern and Western Alps: Constraints from a Late Jurassic gabbro intrusion age in the Glockner Nappe, Tauern Window, Austria
(Springer, 2021)Metabasic rocks of the ophiolitic sequences of the Glockner Nappe and Eclogite Zone in the south-central Tauern Window, Austria, reveal important insights into rifting and spreading of the Alpine Tethys. U–Pb dating of ... -
Context-Aware Stemming algorithm for semantically related root words
(Institute of Electrical and Electronics Engineers (IEEE) Inc., 2012)There is a growing interest in the use of context-awareness as a technique for developing pervasive computing applications that are flexible and adaptable for users. In this context, however, information retrieval (IR) is ... -
Continuing influence of shell effects at high-excitation energies
(Elsevier, 2019)Empirical drops in ground-state nuclear polarizabilities indicate deviations from the effect of giant dipole resonances and may reveal the presence of shell effects in semi-magic nuclei with neutron magic numbers N = 50, ... -
Contour integral method for European options with jumps
(Elsevier, 2013)We develop an efficient method for pricing European options with jump on a single asset. Our approach is based on the combination of two powerful numerical methods, the spectral domain decomposition method and the Laplace ...