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Leonardo Castañeda

Publications and source records attributed to Leonardo Castañeda.

20 records · Page 2Linked to original sources

Study of null geodesic in an axially symmetric space

Since the development of Relativity theory, a variety of solutions have been found around Einstein field equations, depending on the time-space. For instance, we can find the axially symmetric space which describes a rotanting black hole. To understand this astrophysics objects, we must do a ray tracing, which is a simulation of photon's trajectory from the black hole to observer. Since are millions of photons recievied by the observer, we need a computational tool to resolve this problem for generating the image of black hole. Thanks to the YNOGK- GEOKERR code, we can visualise the black holes characteristics and the solutions of the equations of motion using separability and interior point methods. With this article we want to study this type of space and also to show the results for black hole simulations with this routine.

gr-qc↗

Equivalence between formulations in Cosmological Perturbation Theory: The primordial magnetic fields as an example

Nowdays, Cosmological Perturbation Theory is a standard and useful tool in theoretical cosmology. In this work, we compare the 1+3 covariant formalism in perturbation theory (Ellis et al.) to the gauge invariant approach (Bruni et al.), and we show the equivalence of these formalisms to fix the choice of the perturbed variables (gauge choice) in magnetogenesis. We analyze the evolution of primordial magnetic fields through perturbation theory and we discuss the similarities and differences between these two approaches. We get the Maxwell's equations and show a cosmic dynamo like equation written in Poisson gauge, computing the evolution of primordial magnetic fields. Finally, prospects around these formalisms in the study of magnetogenesis are discussed.

gr-qc↗