6 papers
Probing late-time deviations from CDM with a quadratic dark energy expansion
Sehjal Khandelwal, Abraão J. S. Capistrano, Suresh Kumar +1
We investigate the observational viability of a quadratic dark energy expansion (QDEE) model as a phenomenological extension of the standard cosmological framework…
Probing dynamical dark energy with late-time data: Evidence, tensions, and the limits of the CDM framework
Tengpeng Xu, Suresh Kumar, Yun Chen +4
We test the dynamical dark-energy CDM (CPL) framework against CDM using CMB anisotropies and lensing together with DESI DR2, SDSS-IV, transverse/angular BAO (BAOtr), and…
Statistical consistency of sign-switching vacuum energy with cosmological observations
Sehjal Khandelwal, Abraão J. S. Capistrano, Suresh Kumar
We assess dataset agreement and late-time predictive adequacy in CDM and its sign-switching extension, CDM, using a suite of Gaussian and exact non-Gaussian consist…
Probing dynamical embeddings in a five-dimensional spacetime in light of DESI BAO
Abraão J. S. Capistrano, Emanuelly Silva, Rafael C. Nunes +1
We here investigate the observational viability of Nash gravity as an alternative to the standard CDM cosmology. Based on Nash's embedding theorem, the model introduces orthogo…
Shadows and amplitude luminosity of an embedded rotating black hole
Abraao J. S. Capistrano, Antonio C. Gutierrez-Pineres, Carlos H. Coimbra-Araujo
We investigate a rotating black hole embedded in a five-dimensional flat bulk by extending the Kerr metric through the Gurses-Gursey line element. Employing Boyer-Lindquist coordin…
ECO signatures from the Weyl-induced gravitational waveform injection
Abraão J. S. Capistrano, Newton M. S. Chávez, VÃctor A. M. León
We investigate gravitational wave emission from an oscillating star modeled in a static Weyl background using a modulated waveform ansatz. First, we revisit the Weyl metric and obt…