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Luis Santiago Ridao

Publications and source records attributed to Luis Santiago Ridao.

8 recordsLinked to original sources
arXiv2019

Geometrization of gravito-electromagnetic interactions from boundary conditions in the variational principle

We study the conditions of integrability when the boundary terms are considered in the variation of the geometric contribution of the Einstein-Hilbert action. We explore the emergent physical dynamics that is obtained when we make a displacement from a background Riemann manifold to an extended one, on which the non-metricity is nonzero. Under these circumstances, a classical description of electrodynamics and non-perturbative gravitational waves are considered in the extended manifold, when we variate the action.

gr-qc↗
arXiv2018

Gravitons emission during pre-inflation from unified spinor fields

We obtain the equation that describe the conditions of quantization for neutral massless bosons on an arbitrary curved space-time, obtained using a particular theoretical formalism developed in a previous work\cite{MM}. In particular, we study the emission of neutral massless $(1, 2)\hbar$-spin bosons during pre-inflation using the recently introduced unified spinor field theory. We conclude that during pre-inflation (which is governed by an vacuum equation of state), is emitted gravitational radiation, which could be detected in the future, as primordial gravitational radiation.

gr-qc↗
arXiv2018

Inflationary gravitational waves from unified spinor fields

Recent observations of Gravitational Waves (GW) generated by black-hole collisions have opened a new window to explore the universe in diverse scales. Detection of primordial gravitational waves is expected to happen in the next years. However, the standard theory to describe these effects was developed for weak gravitational waves, when their dynamics can be linearized. In this work we develop a non-perturbative formalism to describe GW using the Unified Spinor Fields (USF) theory. The tensor index is calculated and we obtain that it must be $0.0283 <n_T < 0.0407$, in order for the $+$ and $\times$ polarisations modes to have the same spectrum. This imposes some restriction on the constant of self-interaction $3.0018\,<\,ξ^2\,< \,3.0025$ of the fermionic source. The most relevant result here obtained is that the intensity of energy density for GW during inflation is $1.25\times 10^{-4} \left(\frac{m}{H}\right)^2 \, < \,Ω_{GW} \, < \,1.75\times 10^{-4} \left(\frac{m}{H}\right)^2$, where $m$ is the mass of the $1/2$-spin fermionic fields and $H$ the Hubble parameter during inflation. This cut imposes restrictions on the mass of these fields: $\left({m\over H}\right)^2\lesssim 1.1\,h_0^2\times 10^{-11}$.

gr-qc↗
arXiv2018

Emission of primordial bosonic radiation during inflation

We study the emission of neutral massless $(1, 2)\hbar$-spin bosons during power-law inflation using unified spinor field theory. We shows that during inflation gravitons and photons were emitted with wavelengths (on physical coordinates) that increase as the Hubble radius: $λ_{Ph} \sim a/H$. The quantised action related to these bosons is calculated and results to be a fraction of the Planck constant.

gr-qc↗
arXiv2015

Towards relativistic quantum geometry

We obtain a gauge-invariant relativistic quantum geometry by using a Weylian-like manifold with a geometric scalar field which provides a gauge-invariant relativistic quantum theory in which the algebra of the Weylian-like field depends on observers. An example for a Reissner-Nordström black-hole is studied.

hep-th↗
arXiv2015

Discrete Modes in Gravitational Waves from the Big-Bang

We develop a new approach to gravitational waves in which the Einstein equations are governed by the cosmological constant which is related to the existence of a manifold which is closed. We study an example in which the matter Lagrangian is described by the scalar (inflaton) field. There are only three dynamical solutions. In one of them the universe is initially static but begins to increase until an inflationary stage. We calculate the dynamics of GW in this primordial pre-inflationary stage of the universe. We found that there should be an infinite number of polarization modes in order to the fields can be quantized. Finally, we calculate the energy density due to the gravitational waves.

gr-qc↗
arXiv2014

Perihelion advances for the orbits of Mercury, Earth and Pluto from Extended Theory of General Relativity (ETGR)

We explore the geodesic movement on an effective four-dimensional hypersurface that is embedded in a five-dimensional Ricci-flat manifold described by a canonical metric, in order to applying to planetary orbits in our solar system. Some important solutions are given, which provide the standard solutions of general relativity without any extra force component. We study the perihelion advances of Mercury, the Earth and Pluto using the extended theory of general relativity (ETGR). Our results are in very good agreement with observations and show how the foliation is determinant to the value of the perihelion's advances. Possible applications are not limited to these kinds of orbits.

physics.space-ph↗