We apply two variants of Physics-Informed Neural Networks (PINNs) to reconstruct the Type Ia supernova absolute magnitude M_B(z) from joint BAO and supernova data under four cosmological models (\LambdaCDM, CPL, GEDE, \Lambda_sCDM) and two DESI DR2 fiducial sets. A heteroscedastic single-network method tested across four constraint configurations establishes that the Etherington distance...
In general relativity, cosmic acceleration is a statement about geometry---the timelike defocusing of the comoving congruence---and the field equations source it with mass--energy combinations, not with any equation-of-state ratio. Evolving dark energy is now back at the center of cosmology, and several scenarios under active discussion---sign-switching $\Lambda_{\rm s}$CDM and AdS-to-dS...
Recent cosmological data, including DESI DR2, highlight significant tensions within the $\Lambda$CDM paradigm. When analyzed in the context of General Relativity (GR), the latest DESI data favor a dynamical dark energy (DDE) equation of state, $w(z)$, that crosses the phantom divide line $w=-1$. However, this framework prefers a lower Hubble constant, $H_0$, than Planck 2018, thereby worsening...
Recent hints of dynamical dark energy, including a possible crossing of the phantom divide inferred from the latest cosmological data, have motivated the search for viable theoretical explanations. Scalar fields non-minimally coupled to gravity with a coupling of the form $F(\varphi)=1+\alpha\varphi^2$ are physically motivated and have emerged as promising candidates, providing a significantly...
A cosmological pseudo-scalar field provides a compelling realization of dynamical
dark energy (DE). If its coupling to photons is non-negligible, the cosmic microwave background acquires a rotation of its polarization plane, known as cosmic birefringence. We discuss pseudo-scalar models that can simultaneously account for the recent hints of evolution in the equation of state of DE and of the...
The Universal Rotation Curve provides a powerful empirical framework to investigate the distribution of luminous and dark matter in disk galaxies. By adopting normalized radial and velocity coordinates, we investigate the emergence of universal kinematic properties across galaxies with different masses and luminosities. The resulting co-added rotation curves will be analyzed through different...
The Integrated Sachs--Wolfe (ISW) effect probes the late-time evolution of gravitational potentials and provides a complementary test of the nature of dark energy. We investigate whether the redshift evolution of the ISW effect can provide new constraints on the time evolution of dark energy. We consider theoretical predictions for the standard ΛCDM cosmology and alternative w0waCDM models...
