Browsing Researchers in Physics by Title

Now showing items 6-17 of 17

    • Hunting down horizon-scale effects with multi-wavelength surveys 

      Fonseca, Jose; Camera, Stefano; Santos, Mario G.; Maartens, Roy (American Astronomical Society, 2015)
      Next-generation cosmological surveys will probe ever larger volumes of the universe, including the largest scales, near and beyond the horizon. On these scales, the galaxy power spectrum carries signatures of local primordial ...

    • Measuring redshift-space distortion with future SKA surveys 

      Raccanelli, Alvise; Bull, Philip; Camera, Stefano; Bacon, David; Blake, Chris; Dore, Olivier; Ferreira, Pedro G.; Maartens, Roy; Santos, Mario G.; Viel, Matteo; Zhao, Gong-Bo (Proceedings of Science, 2014)
      The peculiar motion of galaxies can be a particularly sensitive probe of gravitational collapse. As such, it can be used to measure the dynamics of dark matter and dark energy as well the nature of the gravitational laws ...

    • Model-independent constraints on dark energy and modified gravity with the SKA 

      Zhao, Gong-Bo; Bacon, David; Maartens, Roy; Santos, Mario G.; Raccanelli, Alvise (Proceedings of Science, 2014)
      Employing a nonparametric approach of the principal component analysis (PCA), we forecast the future constraint on the equation of state w(z) of dark energy, and on the effective Newton constant m(k; z), which parameterise ...

    • Nonlinear modulation of the HI power spectrum on ultra-large scales. I 

      Umeh, Obinna; Maartens, Roy; Santos, Mario G. (IOP Science, 2015)
      Intensity mapping of the neutral hydrogen brightness temperature promises to provide a three-dimensional view of the universe on very large scales. Nonlinear effects are typically thought to alter only the small-scale ...

    • Overview of Cosmology with the SKA 

      Maartens, Roy; Abdalla, Filipe B.; Jarvis, Matt; Santos, Mario G. (Proceedings of Science, 2014)
      The new frontier of cosmology will be led by three-dimensional surveys of the large-scale structure of the Universe. Based on its all-sky surveys and redshift depth, the SKA is destined to revolutionize cosmology, in ...

    • Physical and magnetic properties of biosynthesized ZnO/Fe2O3, ZnO/ZnFe2O4, and ZnFe2O4 nanoparticles 

      Noukelag, Sandrine Kamdoum; Cummings, Franscious; Arendse, Christopher J. (Elsevier B.V., 2023)
      For the first time, the physical and magnetic properties of biosynthesized ZnO/Fe2O3, ZnO/ZnFe2O4, and ZnFe2O4 nanoparticles (NPs) from aqueous extract of rosemary leaves extract are reported. The findings demonstrated the ...

    • Probing the imprint of interacting dark energy on very large scales 

      Duniya, Didam, G. A.; Bertacca, Daniele; Maartens, Roy (American Physical Society, 2015)
      The observed galaxy power spectrum acquires relativistic corrections from light-cone effects, and these corrections grow on very large scales. Future galaxy surveys in optical, infrared and radio bands will probe increasingly ...

    • Testing foundations of modern cosmology with SKA all-sky surveys 

      Schwarz, Dominik J.; Bacon, David; Chen, Song; Clarkson, Chris; Huterer, Dragan; Kunz, Martin; Maartens, Roy; Raccanelli, Alvise; Rubart, Matthias; Starck, Jean-Luc (Proceedings of Science, 2014)
      Continuum and HI surveys with the Square Kilometre Array (SKA) will allow us to probe some of the most fundamental assumptions of modern cosmology, including the Cosmological Principle. SKA all-sky surveys will map an ...

    • Trust is personal and professional: The role of trust in the rise and fall of a South African civil society coalition 

      Piper, Laurence; Anciano, Fiona; Bidla, Babongile (SAGE Publications Ltd, 2023)
      This article explores trust dynamics among a coalition of civil society organizations called Unite Behind that formed in Cape Town, South Africa, in late 2017. Unite Behind was established to demand more accountability ...

    • A wide-angle formulation of foreground filters for HI intensity mapping 

      Kopana, Mponeng; Jolicoeur, Sheean; Maartens, Roy (Springer Nature, 2024)
      The fluctuations generated by Inflation are nearly Gaussian in the simplest models, but may be non-Gaussian in more complex models, potentially leading to signatures in the late Universe. In particular, local-type primordial ...

    • A wide-angle formulation of foreground filters for HI intensity mapping 

      Kothari, Rahul; Maartens, Roy (Institute of Physics, 2024)
      Neutral hydrogen intensity mapping can in principle deliver rapid and large-volume cosmological surveys with exquisitely accurate redshifts that are determined directly from imaging. However, intensity maps suffer from ...

    • The wide-field, multiplexed, spectroscopic facility weave: Survey design, overview, and simulated implementation 

      Jin, Shoko; Jarvis, Matt; Trager, Scott (Oxford University Press, 2024)
      WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, saw first light in late 2022. WEAVE comprises a new 2-deg field-of-view prime-focus corrector system, a ...