Papers by Mauricio Bellini
The Decoherence in the Phase-Space for a Power-Law Expanding Universe in a Globally
The wave function for the matter field fluctuations in the infrared sector is studied within the ... more The wave function for the matter field fluctuations in the infrared sector is studied within the framework of inflationary cosmology. These fluctuations are described by a coarse-grained field which takes into account only the modes with wavelength much bigger than the size of the Hubble horizon. The case of a power-law expanding universe is considered and it is found that the relevant phase-space (φcg, Pφcg ) remains coherent under certain circumstances. In this case the classical stochastic treatment for matter field fluctuations is not valid, however, for p > 4.6, the system loses its coherence and a classical stochastic approximation is allowed. PACS number(s): 98.80.Cq, 04.62.+v Typeset using REVTEX ∗E-mail address: mbellini@mdp.edu.ar 1
Preinflation Without Matter Fromf(R)-Extended General Relativity
SSRN Electronic Journal
arXiv (Cornell University), May 31, 2019
We study a traversable wormhole originated by a transformation over the 4D Dymnikova metric which... more We study a traversable wormhole originated by a transformation over the 4D Dymnikova metric which describes analytic Black-Holes (BH). By using a transformation of coordinates which is adapted from the used in the Einstein-Rosen bridge, we study a specific family of geodesics in which a test particle with non-zero electric charge induces an effective magnetic monopole, that is perceived by observers outside the wormhole. Because the Riemannian geometry cannot explain the presence of magnetic monopoles, then we propose a torsional geometry in order to explore the possibility that magnetic monopoles can be geometrically induced. We obtain an expression that relates torsion and magnetic fields jointly with a Dirac-like expression for magnetic and electric charges, such that torsion makes possible define a fundamental length that provides a magnetic field and a spacetime discretization.
Physics Letters B, Feb 1, 2010
Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin an... more Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. The difference with other previous works is that in this one we use a Lorentz gauge. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of magnetic field modes during the early inflationary epoch of the universe on cosmological scales.
arXiv (Cornell University), May 10, 2019
In this work we explore the boundary conditions in the Einstein-Hilbert action, by considering a ... more In this work we explore the boundary conditions in the Einstein-Hilbert action, by considering a displacement from the Riemannian manifold to an extended one. The latter is characterized by including spinor fields into the quantum geometric description of a noncommutative spacetime. These fields are defined on the background spacetime, emerging from the expectation value of the quantum structure of spacetime generated by matrices that comply with a Clifford algebra. We demonstrate that spinor fields are candidate to describe all known interactions in physics, with gravitation included. In this framework we demonstrate that the cosmological constant Λ, is originated exclusively by massive fermion fields that would be the primordial components of dark energy, during the inflationary expansion of an universe that describes a de Sitter expansion.
arXiv (Cornell University), Oct 24, 2014
We develop a new approach to gravitational waves in which the Einstein equations are governed by ... more 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.
arXiv (Cornell University), Aug 12, 2016
Using Weitzenböck Induced Matter Theory (WIMT), we study Schwarzschild wormholes performing diffe... more Using Weitzenböck Induced Matter Theory (WIMT), we study Schwarzschild wormholes performing different foliations on an extended (non-vaccuum) 5D manifold. We explore the geodesic equations for observers which are in the interior of a traversable wormhole and how these observers can detect gravito-magnetic monopoles which are dual to gravito-electric sources observed in the outer zone of some Schwarzschild Black-Hole (BH). The densities of these monopoles are calculated and quantized in the Dirac sense. This kind of duality on the extended Einstein-Maxwell equations, relates electric and magnetic charges on causally disconnected space regions.
European Physical Journal C, Jun 1, 2016
The pre-inflationary evolution of the universe describes the beginning of the expansion from a st... more The pre-inflationary evolution of the universe describes the beginning of the expansion from a static initial state, such that the Hubble parameter is initially zero, but increases to an asymptotic constant value, in which it could achieve a de Sitter (inflationary) expansion. The expansion is driven by a background phantom field. The back-reaction effects at this moment should describe vacuum geometrical excitations, which are studied in detail in this work using relativistic quantum geometry.
Canadian Journal of Physics, Feb 1, 2019
We study the emission of neutral massless (1, 2)-spin bosons during power-law inflation using uni... more We study the emission of neutral massless (1, 2)-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 P h ∼ a/H. The quantised action related to these bosons is calculated and results to be a fraction of the Planck constant.
European Physical Journal Plus, Dec 1, 2018
Recent observations of Gravitational Waves (GW) generated by black-hole collisions have opened a ... more 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.
arXiv (Cornell University), May 23, 2008
Gravitoectromagnetic Inflation (GI) was introduced to describe in an unified manner, electromagne... more Gravitoectromagnetic Inflation (GI) was introduced to describe in an unified manner, electromagnetic, gravitatory and inflaton fields from a 5D vacuum state. On the other hand, the primordial origin and evolution of dark energy is today unknown. In this letter we show using GI that the zero modes of some redefined vector fields B i = A i /a produced during inflation, could be the source of dark energy in the universe.
arXiv (Cornell University), May 10, 2019
In this work we explore the boundary conditions in the Einstein-Hilbert action, by considering a ... more In this work we explore the boundary conditions in the Einstein-Hilbert action, by considering a displacement from the Riemannian manifold to an extended one. The latter is characterized by including spinor fields into the quantum geometric description of a noncommutative spacetime. These fields are defined on the background spacetime, emerging from the expectation value of the quantum structure of spacetime generated by matrices that comply with a Clifford algebra. We demonstrate that spinor fields are candidate to describe all known interactions in physics, with gravitation included. In this framework we demonstrate that the cosmological constant $\Lambda$, is originated exclusively by massive fermion fields that would be the primordial components of dark energy, during the inflationary expansion of an universe that describes a de Sitter expansion.
arXiv (Cornell University), Apr 1, 2019
We study the conditions of integrability when the boundary terms are considered in the variation ... more 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.
arXiv (Cornell University), Oct 12, 2018
With motivation in the posibility of complexifying the Clifford algebra (CA) of Minkowski spaceti... more With motivation in the posibility of complexifying the Clifford algebra (CA) of Minkowski spacetime by adding an extra dimension, we study the CA of a 5D spacetime with an extra time-like dimension. By considering the 5D massless Dirac equation, we induce the 4D massive Dirac equation and observe that this approach allows us to interpret particles and antiparticles at rest as eigenstates of the generator of rotations in the plane formed by the two time-like coordinates. We also perform the same analysis for the equation in an electromagnetic field. In absence of EM fields we find an effective scale in the fifth coordinate, without proposing it compact. In the presence of EM fields we find a gauge condition to preserve the scale previously found.
arXiv (Cornell University), Mar 22, 2010
Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin an... more Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of electric and magnetic field modes during the early inflationary epoch of the universe on cosmological scales. This is the first time that solutions for the electric field fluctuations are investigated in a systematic way as embeddings for inflationary models in 4D. An important and new result here obtained is that the spectrum of the electric field fluctuations depend with the scale, such that the spectral index increases quadratically as the scale decreases.
arXiv (Cornell University), Dec 18, 2007
Introducing a variable cosmological parameter Λ(t) in a geometrical manner from a 5D Riemannflat ... more Introducing a variable cosmological parameter Λ(t) in a geometrical manner from a 5D Riemannflat metric, we investigate the origin and evolution of primordial magnetic fields in the early universe, when the expansion is governed by a cosmological parameter Λ(t) that decreases with time. Using the gravitoelectromagnetic inflationary formalism, but without the Feynman gauge, we obtain the power of spectrums for large-scale magnetic fields and the inflaton field fluctuations during inflation. A very important fact is that our formalism is naturally non-conformally invariant.
arXiv (Cornell University), Sep 30, 2009
Using some ideas of Modern Kaluza-Klein theory, we examine the evolution of entropy on a 4D Fried... more Using some ideas of Modern Kaluza-Klein theory, we examine the evolution of entropy on a 4D Friedmann-Robertson-Walker (FRW) brane from a 5D vacuum state, which is defined on a 5D background Riemann-flat metric. We found that entropy production is sufficiently important during inflation: S > 10 90 , for all the initial values of temperature T 0 < T GU .
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="d1e971" altimg="si9.svg"><mml:mi>B</mml:mi></mml:math>-mode of gravitational waves in preinflation with negative spatial curvature
Physics of the Dark Universe, May 1, 2023
arXiv (Cornell University), Jun 9, 2009
We study phantom and inflationary cosmologies using form-invariance transformations of the Einste... more We study phantom and inflationary cosmologies using form-invariance transformations of the Einstein equations with respect to ρ, H, a and p, from a 5D vacuum. Equations of state and squared fluctuations of the inflaton and phantom fields are examined.
Journal of Cosmology and Astroparticle Physics, Oct 4, 2010
Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin an... more Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. We use simultaneously the Lorentz and Feynman gauges. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of electric and magnetic field modes during the early inflationary epoch of the universe on cosmological scales. This is the first time that solutions for the electric field fluctuations are investigated in a systematic way as embeddings for inflationary models in 4D. An important and new result here obtained is that the spectrum of the electric field fluctuations depend with the scale, such that the spectral index increases quadratically as the scale decreases.
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Papers by Mauricio Bellini