Gravitationally generated interactions (original) (raw)
Related papers
Towards the Unification of Gravity and other Interactions: What has been Missed?
Journal of Physics: Conference Series 222 (2010) 012017, 2010
Faced with the persisting problem of the unification of gravity with other fundamental interactions we investigate the possibility of a new paradigm, according to which the basic space of physics is a multidimensional space C associated with matter configurations. We consider general relativity in C. In spacetime, which is a 4-dimensional subspace of C, we have not only the 4-dimensional gravity, but also other interactions, just as in Kaluza-Klein theories. We then consider a finite dimensional description of extended objects in terms of the center of mass, area, and volume degrees of freedom, which altogether form a 16-dimensional manifold whose tangent space at any point is Clifford algebra Cl(1,3). The latter algebra is very promising for the unification, and it provides description of fermions.
Unification of Gravity and Internal Interactions
Fortschritte der Physik, 2023
In the gauge theoretic approach of gravity, General Relativity is described by gauging the symmetry of the tangent manifold in four dimensions. Usually the dimension of the tangent space is considered to be equal to the dimension of the curved manifold. However, the tangent group of a manifold of dimension d is not necessarily SO(d). It has been suggested earlier that by gauging an enlarged symmetry of the tangent space in four dimensions one could unify gravity with internal interactions. Here we consider such a unified model by gauging the SO (1,17) as the extended Lorentz group overcoming in this way some difficulties of the previous attempts of similar unification and eventually we obtain the SO(10) GUT, supplemented by an SU(2)×SU(2) global symmetry.
A Geometrical unification of gravitation and electromagnetism in five-dimensional space-time
arXiv (Cornell University), 2010
We consider in this paper, the geometrization of classical physics, i.e gravitation and electromagnetism. The goal is therefore to show that all the usual physical concepts, such as mass, energy, charge, trajectory, Maxwell-Lorentz law, are only various aspects of the geometry, for exemple curvature, of spacetime considered as a Lorentzian manifold; that is no object is "put" in spacetime, no laws are given, everything is only geometry. We show why this goal is probably inaccessible in dimension 4, and put forward, while studying this case, the concepts leading to a solution in a five-dimensional spacetime. The solution we propose does not use truly new mathematics, but more a different view of the classical axiomatism of the classical theories, and in particular the suppression of an hypothesis usually made about the Ricci curvature, unjustified from our point of view. This work is therefore in the continuation of the various attempts made since Einstein, Weyl, Nordstrom, Kaluza, Klein, Rainich, Wheeler.
A spin-4 analog of 3D massive gravity
Classical and Quantum Gravity, 2011
A 6th-order, but ghost-free, gauge-invariant action is found for a 4th-rank symmetric tensor potential in a three-dimensional (3D) Minkowski spacetime. It propagates two massive modes of spin 4 that are interchanged by parity, and is thus a spin-4 analog of linearized "new massive gravity". Also found are ghost-free spin-4 analogs of linearized "topologically massive gravity" and "new topologically massive gravity", of 5th- and 8th-order respectively.
Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is aimed to address conceptual and experimental problems recently emerged in Astrophysics, Cosmology and High Energy Physics. In particular, the goal is to encompass, in a self-consistent scheme, problems like Inflation, Dark Energy, Dark Matter, Large Scale Structure and, first of all, to give at least an effective description of Quantum Gravity. We review the basic principles that any gravitational theory has to follow. The geometrical interpretation is discussed in a broad perspective in order to highlight the basic assumptions of General Relativity and its possible extensions in the general framework of gauge theories. Principles of such modifications are presented, focusing on specific classes of theories like f (R)-gravity and scalar-tensor gravity in the metric and Palatini approaches. The special role of torsion is also discussed. The conceptual features of these theories are fully explored and attention is payed to the issues of dynamical and conformal equivalence between them considering also the initial value problem. A number of viability criteria are presented considering the post-Newtonian and the post-Minkowskian limits. In particular, we discuss the problems of neutrino oscillations and gravitational waves in Extended Gravity. Finally, future perspectives of Extended Gravity are considered with possibility to go beyond a trial and error approach.
2020
In this work, using differential forms, an alternative approach to matter coupling in Minimal Massive 3D Gravity (MMG) is presented. In the first part, we consider the minimal coupling of matter Lagrangian assuming that matter Lagrangian 3-form depends on the metric co-frame fields and some matter fields but not on the connections. We construct additional source 2-form to obtain a consistent matter-coupled MMG theory. We see that additional source 2-form involves terms that are quadratic in stress-energy 2-forms. In addition, we derive consistency relation in the language of differential forms. Next, we consider minimal coupling of Dirac Lagrangian where for this case massive spinor-matter Lagrangian depends on both metric co-frames and connection fields. To get a consistent spinor-matter coupled MMG field equation, we obtain additional source 2-form as well. It is shown that with spinor coupling, source 2-form involves terms which are quadratic in covariant derivatives of spinor fi...
Generalized modified gravity in large extra dimensions
Physics Letters B, 2006
We discuss effective interactions among brane matter induced by modifications of higher-dimensional Einstein gravity through the replacement of Einstein–Hilbert term with a generic function f(R,RABRAB,RABCDRABCD)f(R,RABRAB,RABCDRABCD) of the curvature tensors. We determine gravi-particle spectrum of the theory, and perform a comparative analysis of its predictions with those of the Einstein gravity within Arkani-Hamed–Dvali–Dimopoulos (ADD) setup. We find that this general higher-curvature quantum gravity theory contributes to scatterings among both massive and massless brane matter (in contrast to much simpler generalization of the Einstein gravity, f(R)f(R), which influences only the massive matter), and therefore, can be probed via various scattering processes at present and future colliders and directly confronted with the ADD expectations. In addition to collision processes which proceed with tree-level gravi-particle exchange, effective interactions among brane matter are found to exhibit a strong sensitivity to higher-curvature gravity via the gravi-particle loops. Furthermore, particle collisions with missing energy in their final states are found to be sensitive to additional gravi-particles not found in Einstein gravity. In general, road to a correct description of quantum gravity above Fermi energies depends crucially on if collider and other search methods end up with a negative or positive answer for the presence of higher-curvature gravitational interactions.
arXiv (Cornell University), 2010
We propose in this paper a mathematicians' view of the Kaluza-Klein idea of a five dimensional space-time unifying gravitation and electromagnetism. By considering the classification of positive Einstein curvature tensors and the classical Cauchy-Choquet-Bruhat theorems in general relativity, we introduce concepts of types and rigidity. Then, abandoning the usual requirement of a Ricci-flat five dimensional space-time, we show that a unified geometrical frame can be set for gravitation and electromagnetism, giving, by projection on the classical 4-dimensional space-time, the known Einstein-Maxwell-Lorentz equations for charged fluids. Thus, although not introducing, at least at this stage, new physics, we get a very aesthetic presentation of classical physics in the spirit of general relativity. The usual physical concepts, such as mass, energy, charge, trajectory, Maxwell-Lorentz law, are shown to be only various aspects of the geometry, for example curvature, of space-time considered as a Lorentzian manifold; that is no physical objects are introduced in space-time, no laws are given, everything is only geometry! This work is therefore in the continuation of the various attempts made since Einstein, Weyl, Nordstrom, Kaluza, Klein, Rainich, Wheeler.