arXiv subjects

M. Novello

Publications and source records attributed to M. Novello.

At least 37 records · Page 2Linked to original sources

arXiv2013

Geometric scalar theory of gravity

We present a geometric scalar theory of gravity. Our proposal will be described using the "background field method" introduced by Gupta, Feynman and others as a field theory formulation of general relativity. We analyze previous criticisms against scalar gravity and show how the present proposal avoids these difficulties. This concerns not only the theoretical complaints but also those related to observations. In particular, we show that the widespread belief of the conjecture that the source of scalar gravity must be the trace of the energy-momentum tensor - which is one of the main difficulties to couple gravity with electromagnetic phenomenon in previous models - does not apply to our geometric scalar theory. Some consequences of the new scalar theory are explored.

gr-qc↗

arXiv2012

Gordon Metric Revisited

We show that Gordon metric belongs to a larger class of geometries, which are responsible to describe the paths of accelerated bodies in moving dielectrics as geodesics in a metric $\hat q_{μν}$ different from the background one. This map depends only on the background metric and on the motion of the bodies under consideration. As a consequence, this method describes a more general property that concerns the elimination of any kind of force acting on bodies by a suitable change of the substratum metric.

gr-qc↗

arXiv2012

What is the origin of the mass of the Higgs boson?

The purpose of this paper is to present a unified description of mass generation mechanisms that have been investigated so far and that are called the Mach and Higgs proposals. In our mechanism, gravity acts merely as a catalyst and the final expression of the mass depends neither on the intensity nor on the particular properties of the gravitational field. We shall see that these two strategies to provide mass for all bodies that operate independently and competitively can be combined into a single unified theoretical framework. As a consequence of this new formulation we are able to present an answer to the question: what is the origin of the mass of the Higgs boson?

gr-qc↗

arXiv2012

Dragged Metrics

We show that the path of any accelerated body in an arbitrary space-time geometry $g_{μν}$ can be described as geodesics in a dragged metric $\hat{q}_{μν}$ that depends only on the background metric and on the motion of the body. Such procedure allows the interpretation of all kind of non-gravitational forces as modifications of the metric of space-time. This method of effective elimination of the forces by a change of the metric of the substratum can be understood as a generalization of the d'Alembert principle applied to all relativistic processes.

physics.gen-ph↗

arXiv2011

The gravitational mechanism to generate mass II

With the eminent confirmation or disproof of the existence of Higgs boson by experiments on the LHC it is time to analyze in a non-dogmatic way the suggestions to understand the origin of the mass. Here we analyze the recent proposal according to which gravity is what is really responsible for the generation of mass of all bodies. The great novelty of such mechanism is that the gravitational field acts merely as a catalyst, once the final expression of the mass does not depend either on the intensity or on the particular characteristics of the gravitational field.

gr-qc↗

arXiv2011

Electromagnetic Geometry

We show that Maxwell's electromagnetism can be mapped into the Born-Infeld theory in a curved space-time, which depends only on the electromagnetic field in a specific way. This map is valid for any value of the two lorentz invariants $F$ and $G$ confirming that we have included all possible solutions of Maxwell's equations. Our result seems to show that specifying the dynamics and the space-time structure of a given theory can be viewed merely as a choice of representation to describe the physical system.

gr-qc↗

arXiv2011

Hidden geometries in nonlinear theories: a novel aspect of analogue gravity

We show that non-linear dynamics of a scalar field ϕ may be described as a mod- ification of the spacetime geometry. Thus, the self-interaction is interpreted as a coupling of the scalar field with an effective gravitational metric that is constructed with ϕ itself. We prove that this process is universal, that is, it is valid for arbi- trary Lagrangian. Our results are compared to usual analogue models of gravitation, where the emergence of a metric appears as a consequence of linear perturbation.

gr-qc↗

arXiv2011

Beyond Analog Gravity: The Case of Exceptional Dynamics

We show that it is possible to go beyond the simple kinematical aspects of the analog models of gravity. We exhibit the form of the Lagrangian that describes the dynamics of a self-interacting field $ ϕ$ as an interaction between $ ϕ$ and its associated effective metric $ \hat{g}^{μν}.$ In other words the non-linear equation of motion of the field may be interpreted as the gravitational influence on $ ϕ$ by its own effective metric which, in our scheme becomes an active partner of the dynamics of $ ϕ. $

gr-qc↗

arXiv2010

Mach or Higgs? The mechanisms to generate mass

The purpose of this work is to show that the gravitational interaction is able to generate mass for all bodies. The condition for this is the existence of an energy distribution represented by the vacuum or the cosmological constant term $ Λ\, g_{μν}.$ We review briefly the alternative Higgs mechanism in order to compare both processes.

physics.gen-ph↗

arXiv2010

Gaussian coordinate systems for the Kerr metric

We present the whole class of Gaussian coordinate systems for the Kerr metric. This is achieved through the uses of the relationship between Gaussian observers and the relativistic Hamilton-Jacobi equation. We analyze the completeness of this coordinate system. In the appendix we present the equivalent JEK formulation of General Relativity -- the so-called quasi-Maxwellian equations -- which acquires a simpler form in the Gaussian coordinate system. We show how this set of equations can be used to obtain the internal metric of the Schwazschild solution, as a simple example. We suggest that this path can be followed to the search of the internal Kerr metric.

gr-qc↗

arXiv2010

A gravitational mechanism which gives mass to the vectorial bosons

A mechanism in which gravity is the responsible for the generation of the mass of scalar bosons and fermions was proposed recently [arXiv:1003.5126]. The purpose of the present paper is to extend this scheme to vector bosons. The main characteristic of this mechanism is that the gravitational field acts really as a catalyzer, once the final expression of the mass we obtained depends neither on the intensity of the gravitational field nor on the value of Newton's constant.

physics.gen-ph↗

arXiv2010

A mechanism to generate mass: the case of fermions

In a recent paper \cite{novello} we have presented a mechanism to generate mass from gravitational interaction, based on the Mach principle, according to which the inertia of a body is a property of matter as well as of the background provided by the rest-of-the-universe. In \cite{novello} we realized such an idea for a scalar field treating the rest-of-the-universe in its vacuum state. In the present paper we describe a similar mechanism for fermions.

physics.gen-ph↗

arXiv2009

On a Geometrical Description of Quantum Mechanics

We show that Quantum Mechanics can be interpreted as a modification of the Euclidean nature of 3-d space into a particular Weyl affine space which we call Q-wis. This is proved using the Bohm-de Broglie causal formulation of Quantum Mechanics. In the Q-wis geometry, the length of extended objects changes from point to point. In our proposed geometrical formulation, deformation of the standard rulers used to measure physical distances are in the core of quantum effects.

gr-qc↗

arXiv2008

Non-singular solutions in multidimensional cosmology with a perfect fluid: acceleration and variation of G

Exact solutions with an exponential behaviour of the scale factors are considered in a multidimensional cosmological model describing the dynamics of n+1 Ricci-flat factor spaces M_i in the presence of a one-component perfect fluid. The pressures in all spaces are proportional to the density: p_i = w_i ρ, i = 0,...,n. Solutions with accelerated expansion of our 3-space M_0 and a small enough variation of the gravitational constant G are found. These solutions exist for two branches of the parameter w_0. The first branch describes superstiff matter with w_0 > 1, the second one may contain phantom matter with w_0 < - 1.

hep-th↗

arXiv2008

Cyclic Magnetic Universe

Recent works have shown the important role Nonlinear Electrodynamics (NLED) can have in two crucial questions of Cosmology, concerning particular moments of its evolution for very large and for low-curvature regimes, that is for very condensed phase and at the present period of acceleration. We present here a toy model of a complete cosmological scenario in which the main factor responsible for the geometry is a nonlinear magnetic field which produces a FRW homogeneous and isotropic geometry. In this scenario we distinguish four distinct phases: a bouncing period, a radiation era, an acceleration era and a re-bouncing. It has already been shown that in NLED a strong magnetic field can overcome the inevitability of a singular region typical of linear Maxwell theory; on the other extreme situation, that is for very weak magnetic field it can accelerate the expansion. The present model goes one step further: after the acceleration phase the universe re-bounces and enter in a collapse era. This behavior is a manifestation of the invariance under the dual map of the scale factor $ a(t) \to 1/ a(t),$ a consequence of the corresponding inverse symmetry of the electromagnetic field ($ F \to 1/ F,$ where $F \equiv F^{μν}F_{μν}$) of the NLED theory presented here. Such sequence collapse-bouncing-expansion-acceleration-re-bouncing-collapse constitutes a basic unitary element for the structure of the universe that can be repeated indefinitely yielding what we call a Cyclic Magnetic Universe.

astro-ph↗

arXiv2008

Bouncing Cosmologies

We review the general features of nonsingular universes ({\em i.e.} those that go from an era of accelerated collapse to an expanding era without displaying a singularity) as well as cyclic universes. We discuss the mechanisms behind the bounce, and analyze examples of solutions that implement these mechanisms. Observational consequences of such regular cosmologies are also considered, with emphasis in the behavior of the perturbations.

astro-ph↗

arXiv2007

Cosmological redshift and nonlinear electrodynamics propagation of photons from distant sources

By-now photons are the unique universal messengers. Cosmological sources like far-away galaxies or quasars are well-known light-emitters. Here we demonstrate that the nonlinear electrodynamics (NLED) description of photon propagation through the weak background intergalactic magnetic fields modifies in a fundamental way the cosmological redshift that a direct computation within a specific cosmological model can abscribe to a distant source. Independently of the class of NLED Lagrangian, the effective redshift turns out to be $1 + \tilde{z} = (1 + z) Δ$, where $Δ\equiv (1 + Φ_e)/(1 + Φ_o)$, with $Φ\equiv {8}/{3} ({L_{FF}}/{L_F}) B^2$, being $L_F = {dL}/{dF}$, $L_{FF} = {d^2L}/{dF^2}$, the field $F\equiv F_{αβ} F^{αβ}$, and $B$ the magnetic field strength. Thus the effective redshift is always much higher then the standard redshift, but recovers such limit when the NLED correction $Δ(Φ_e, Φ_o) \longrightarrow 1$. This result may provide a physical foundation for the current observation-inspired interpretation that the universe undergoes an accelerate expansion. However, under the situation analyzed here, for any NLED the actual (spatial) position of the light-emitting far-away source remains untouched.

astro-ph↗

arXiv2007

Constructing Dirac linear fermions in terms of non-linear Heisenberg spinors

We show that the massive (or massless) neutrinos can be described as special states of Heisenberg nonlinear spinors. As a by-product of this decomposition a particularly attractive consequence appears: the possibility of relating the existence of only three species of mass-less neutrinos to such internal non-linear structure. At the same time it allows the possibility that neutrino oscillation can occurs even for massless neutrinos.

astro-ph↗