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J. Buitrago

Publications and source records attributed to J. Buitrago.

12 recordsLinked to original sources
arXiv2023

Rotation curves of galaxies via Reissner-Nordstrom induced gravity and an alternative explanation of Dark Matter

The dynamics of a neutral test particle in the spacetime geometry cor-responding to a central massive and charged object (Reissner-Nordstrom Metric) is examined. For a radial distance r = Q^2/M (in natural units) the gravitational force is null, independently of the value of G, and repulsive below this value. It is shown that within typical atomic and molecular distances, there is a repulsive force albeit negligible in comparison with the electromagnetic one ruling the atomic world. For an eventual extremal black hole having a mass equal to the Planck Mass a limit to electric charge equal to 1(MeV )^0 is found. At the galactic scale and for galaxies with a compact central nucleus with mass below or of the order of the Solar mass, the repulsive force can reproduce the flat rotation curve of stellar orbits observed in many galaxies.

physics.gen-ph↗
arXiv2021

Local SU(3) gauge invariance in Weyl 2-spinor language and quark-gluon plasma equations of motion

In a new Weyl 2-spinor approach to Non abelian Gauge Theories, starting with the local U(1) Gauge group of a previous work, we study now the SU(3) case corresponding to quarks (antiquarks) interacting with color fields. The principal difference with the conventional approach is that particle-field interactions are not described by means of potentials but by the field strength magnitudes. Some analytical expressions showing similarities with electrodynamics are obtained. Classical equations that describe the behavior of quarks under gluon fields might be in principle applied to the quark-gluon plasma phase existing during the first instants of the Universe.

hep-th↗
arXiv2020

Relativistic correction to the Bohr radius and electron distance expectation value via Dirac Equation

In this article and beginning with the Dirac solution to the Hydrogen atom in its ground state, the exact results corresponding to the expectation value of the distance of the electron to the proton and the maximum probability distance are found. For hydrogen-like atoms and in contrast to the non relativistic Bohr radius and expectation values, for $Z=\frac{\sqrt3}{2}\frac{1}α$ (close to 118), the expectation distance to the nucleus is zero thus putting an end to the periodic table for Z = 118 nicely matching the last element discovered (Oganesson).

physics.gen-ph↗
arXiv2020

Electron internal energy and internal motion (Zitterbewegung) as consequence of local U(1) gauge invariance in two-spinor language

Starting with the results obtained in a previous paper in which classical local U(1) gauge invariance in terms of the electromagnetic field strenghts instead of the usual formulation mediated by the four potential was introduced it is shown that using the gauge freedom associated with the third component of the magnetic field, previously obtained spinor equations of motion describe the internal dynamics of a free 1/2 spin particle suggesting a kinematic origin of its rest mass and helicity. The controversial Zitterbewegung (trembling motion) appears in a natural way as internal motion with the velocity of light. Such an interpretation is in contrast with the usual quantum mechanical explanation of transitions between positive and negative energy states.

physics.gen-ph↗
arXiv2020

Unified Picture of Electromagnetic and Gravitational Forces in Two-Spinor Language

The well known Geodesic Equation of General Relativity is newly formulated in Weyl two-spinor language in a convenient way susceptible of being combined with a set of two-spinor equations, equivalent to the Lorentz Force of Electrodynamics, obtained in previous studies. General spinor equations of motion for a test charged spin 1/2 particle in arbitrary electromagnetic and gravitational fields fields are obtained describing not only spacetime trajectories but also spin precession. For the case of the Schwarzschild metric and radial trajectories, spinor equations unifying gravitational and electric forces are obtained and solved for a weak gravitational field (or long distance from the source).

gr-qc↗
arXiv2014

Charge quantization emerging from irreducible representations of the gauge group U(1) and local gauge invariance in 2-spinor lenguage

A new classical 2-spinor approach to $U(1)$ gauge theory is presented in which the usual four-potential vector field is replaced by a symmetric second rank spinor. Following a lagrangian formulation, it is shown that the four-rank spinor representing the Maxwell field tensor has a $U(1)$ local gauge invariance in terms of the electric and magnetic field strengths. When applied to the magnetic field of a monopole, this formulation, via the irreducible representations condition for the gauge group, leads to a quantization condition differing by a factor 2 of the one predicted by Dirac without relying on any kind of singular vector potentials.

hep-th↗
arXiv2011

Classical Weyl-Spinor approach to U(1) and non-abelian local gauge theories

In a previous paper we introduced two linear spinor equations equivalent to the Lorentz Force and stated that these equations were fairly general and could be applied to any force field compatible with Special Relativity. In this paper, via a lagrangian approach, we explore this possibility and obtain classical spinor equations describing the behaviour of fermionic particles not only under an electromagnetic field but also under Yang-Mills and Color fields. We find a covariant derivative defined {\it along the classical trajectory} of the particle, which can be extended to SU(2) and SU(3) local symmetries, and obtain the Yang-Mills and Color fields in a new classical Weyl-spinor approach to Gauge Theories. In the SU(3) case, the obtained equations which describe the behaviour of quarks under gluon fields could be in principle applied to the quark-gluon plasma phase existing during the first instants of the Universe.

hep-th↗
arXiv2009

Electromagnetic Force as consequence of the Geometry of Minkowskian Spacetime

By describing the dynamical evolution of a test charged particle in the presence of an electromagnetic field as a succession of infinitesimal Lorentz boosts and rotations it is possible to obtain the Lorentz Force of Electrodynamics. A consequence of this derivation at the classical level is that, given the existence of electric and magnetic fields, the form of the electromagnetic force acting on the particle can be regarded as arising from the geometry of Minkowskian spacetime.

math-ph↗
arXiv2009

Spinor extended Lorentz-force like equations as consequence of a spinorial structure of space-time

As previously shown, the special relativistic dynamical equation of the Lorentz force type can be regarded as a consequence of a succession of space-time dependent infinitesimal Lorentz boosts and rotations. This insight indicate that the Lorentz-Force-like equation has a fundamental meaning in physics. We show how this result may be spinorially obtained starting out out from the application of an infinitesimal element of SL(2,C) to the individual spinors, which are regarded here as being more fundamental objects than four-vectors. In this way we get a set of new dynamical spinor equations inducing the extended Lorentz-Force-like equation in the Minkowski space-time and geometrically obtain the spinor form of the electromagnetic field tensor. The term extended refers to the dynamics of some additional degrees of freedom that may be associated with the intrinsic spin, namely, with the dynamics of three spacelike mutually orthogonal four-vectors, all of them orthogonal to the linear four-momentum of the object under consideration that finally, in the particle's proper frame. are identified with the generators of SU(2).

math-ph↗
arXiv1999

Spectroscopy of the Lens Galaxy of Q0957+561A,B. Implications of a possible central massive dark object

We present new long-slit William Herschel Telescope spectroscopic observations of the lens galaxy G1 associated with the double-imaged QSO 0957+561A,B. The obtained central stellar velocity dispersion, sigma_l = 310 +/- 20 km/s, is in reasonable agreement with other measurements of this dynamical parameter. Using all updated measurements of the stellar velocity dispersion in the internal region of the galaxy (at angular separations < 1".5) and a simple isotropic model, we discuss the mass of a possible central massive dark object. It is found that the data of Falco et al. (1997) suggest the existence of an extremely massive object of (0.5-2.1) x 10E10/h M_\odot (80% confidence level), whereas the inclusion of very recent data (Tonry & Franx 1998, and this paper) substantially changes the results: the compact central mass must be $\le$ 6 x10E9/h M_\odot at the 90% confidence level. We note that, taking into account all the available dynamical data, a compact nucleus with a mass of 10E9/h M_\odot (best fit) cannot be ruled out.

astro-ph↗
arXiv1998

Gravitational Lenses and the Hubble Constant : Present and Future

The best studied gravitational lens is the Twin QSO Q0957+561, and as a result of recent advances in observations and modelling, a ten percent measurement of the Hubble constant is attainable. We discuss in detail this system and review the perspectives in a near future.

astro-ph↗