14,891 research outputs found
On geometric relativistic foundations of matter field equations and plane wave solutions
In this paper, we start from the geometric relativistic foundations to define
the basis upon which matter field theories are built, and their wave solutions
are investigated, finding that they display repulsive interactions able to
reproduce the exclusion principle in terms of its effects in a dynamical way,
then discussing possible consequences and problems.Comment: 11 page
A torsional completion of gravity for Dirac matter fields and its applications to neutrino oscillations
In this paper, we consider the torsional completion of gravitation for an
underlying background filled with Dirac fields, applying it to the problem of
neutrino oscillations: we discuss the effects of the induced torsional
interactions as corrections to the neutrino oscillation mechanism.Comment: 4 page
Conformal Gravity with Electrodynamics for Fermion Fields and their Symmetry Breaking Mechanism
In this paper we consider an axial torsion to build metric-compatible
connections in conformal gravity, with gauge potentials; the geometric
background is filled with Dirac spinors: scalar fields with suitable potentials
are added eventually. The system of field equations is worked out to have
torsional effects converted into spinorial self-interactions: the massless
spinors display self-interactions of a specific form that gives them the
features they have in the non-conformal theory but with the additional
character of renormalizability, and the mechanisms of generation of mass and
cosmological constants become dynamical. As a final step we will address the
cosmological constant and coincidence problems.Comment: 13 page
Fourth derivative gravity in the auxiliary fields representation and application to the black hole stability
We consider an auxiliary fields formulation for the general fourth-order
gravity on an arbitrary curved background. The case of a Ricci-flat background
is elaborated in full details and it is shown that there is an equivalence with
the standard metric formulation. At the same time, using auxiliary fields helps
to make perturbations to look simpler and the results more clear. As an
application we reconsider the linear perturbations for the classical
Schwarzschild solution. We also briefly discuss the relation to the effect of
massive unphysical ghosts in the theory.Comment: 11 pages, no figure
Multi-band spectroscopy of inhomogeneous Mott-insulator states of ultracold bosons
In this work, we use inelastic scattering of light to study the response of
inhomogeneous Mott-insulator gases to external excitations. The experimental
setup and procedure to probe the atomic Mott states are presented in detail. We
discuss the link between the energy absorbed by the gases and accessible
experimental parameters as well as the linearity of the response to the
scattering of light. We investigate the excitations of the system in multiple
energy bands and a band-mapping technique allows us to identify band and
momentum of the excited atoms. In addition the momentum distribution in the
Mott states which is spread over the entire first Brillouin zone enables us to
reconstruct the dispersion relation in the high energy bands using a single
Bragg excitation with a fixed momentum transfer.Comment: 19 pages, 7 figure
On Geometrically Unified Fields and Universal Constants
We consider the Cartan extension of Riemann geometry as the basis upon which
to build the Sciama--Kibble completion of Einstein gravity, developing the most
general theory in which torsion and metric have two independent coupling
constants: the main problem of the ESK theory was that torsion, having the
Newton constant, was negligible beyond the Planck scale, but in this
theory torsion, with its own coupling constant, may be
relevant much further Planck scales; further consequences of these
torsionally-induced interactions will eventually be discussed.Comment: 10 page
A modified theory of gravity with torsion and its applications to cosmology and particle physics
In this paper we consider the most general least-order derivative theory of
gravity in which not only curvature but also torsion is explicitly present in
the Lagrangian, and where all independent fields have their own coupling
constant: we will apply this theory to the case of ELKO fields, which is the
acronym of the German \textit{Eigenspinoren des LadungsKonjugationsOperators}
designating eigenspinors of the charge conjugation operator, and thus they are
a Majorana-like special type of spinors; and to the Dirac fields, the most
general type of spinors. We shall see that because torsion has a coupling
constant that is still undetermined, the ELKO and Dirac field equations are
endowed with self-interactions whose coupling constant is undetermined: we
discuss different applications according to the value of the coupling constants
and the different properties that consequently follow. We highlight that in
this approach, the ELKO and Dirac field's self-interactions depend on the
coupling constant as a parameter that may even make these non-linearities
manifest at subatomic scales.Comment: 21 page
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