6 papers
Hubble tension in k-essence: Evidence for robust tension alleviation
Isaac Opio, Didam Duniya, Bishop Mongwane +1
The Hubble tension has come to stay as a major problem in modern cosmology as it continues to plague the standard cosmological model (CDM). As one of the viable, self-consisten…
Relativistic effects in k-essence
Didam Duniya, Isaac Opio, Bishop Mongwane +1
Relativistic effects are sensitive to subtle changes in dark energy. These effects grow on very large scales and at high redshifts, which will be the reach of upcoming surveys. We…
Massive star clusters and clumps in the collisional ring galaxy Arp 147
Z. Randriamanakoto, M. Rakototafika, B. Mongwane +2
We conduct a photometric study of star clusters (or knots) in the collisional ring galaxy (CRG) Arp 147 to trace the star formation history across its empty ring. Using HST F450W,…
Cosmic magnification in beyond-Horndeski gravity
Didam Duniya, Bishop Mongwane
Cosmic magnification is able to probe the geometry of large-scale structure on cosmological scales, thereby providing another window for probing theories of the late-time cosmic ac…
Investigating the imprint of quintessence in cosmic magnification
Enas Mohamed, Didam Duniya, Hassan Abdalla +1
We study cosmic magnification beyond lensing in a late-time universe dominated by quintessence and cold dark matter. The cosmic magnification angular power spectrum, especially goi…
Quasinormal modes of a Schwarzschild black hole within the Bondi-Sachs framework
Bishop Mongwane, Sipho Nkele, Didam G. A. Duniya +1
Studies of quasinormal modes (QNMs) of black holes have a long and well established history. Predominantly, much research in this area has customarily focused on the equations give…