3 papers
gr-qc2025
Boundary terms in cosmology
Ãngel Cuevas, Javier Chagoya, C. Ortiz
In the derivation of the Einstein field equations via Hamilton's principle, the inclusion of a boundary term is essential to render the variational problem well-posed, as it addres…
gr-qc2025
Shadows of black holes in dynamical Chern-Simons modified gravity
Benito RodrÃguez, Javier Chagoya, C. Ortiz
We revisit and extend the study of null geodesics around a slowly rotating black hole in Chern-Simons modified gravity. We employ the Hamilton-Jacobi formalism to derive the equati…
gr-qc2025
Constraining modified gravity models through strong lensing cosmography
Mario H. Amante, Andrés Lizardo, Javier Chagoya +1
We analyze cosmography as a tool to constrain modified gravity theories. We take four distinct models and obtain their parameters in terms of the cosmographic parameters favored by…