61 research outputs found
A Bargmann-Wightman-Wigner Type Quantum Field Theory
This version corrects an inportant typographical error in Eq. 17. COMMENTS,
FOR THE RECORD: A referees reoprt from Phys. Rev. Lett. read in part ``The
first named author has appreciated my exceptionally long report. He has read
and well assimilated the literature I suggested. Congratulations! This very new
version of the manuscript has now three authors and carries a very well chosen
title. Indeed Bargmann, Wightman and Wigner had studied, this subject forty
years ago, in an unpublished book (several chapters were distributed as
preprints). The authors explain well the scope of their paper. They have made a
thorough construction of a field theory of a non usual Wigner type; that is
completely new and all references are relevant. {\it This paper should be
published.}" Despite the fact that no other report was received, the editors of
Phys. Rev. Lett. rejected this paper.
D.V.A.Comment: 13 pages, RevTex, LA-UR-92-3726-RE
Zero Energy of Plane-Waves for ELKOs
We consider the ELKO field in interaction through contorsion with its own
spin density, and we investigate the form of the consequent autointeractions;
to do so we take into account the high-density limit and find plane wave
solutions: such plane waves give rise to contorsional autointeractions for
which the Ricci metric curvature vanishes and therefore the energy density is
equal to zero identically. Consequences are discussed.Comment: 7 page
Quantum Measurement, Gravitation, and Locality
This essay argues that when measurement processes involve energies of the
order of the Planck scale, the fundamental assumption of locality may no longer
be a good approximation. Idealized position measurements of two distinguishable
spin- particles are considered. The measurements alter the space-time metric
in a fundamental manner governed by the commutation relations and the classical field equations of gravitation. This
{\it in-principle} unavoidable change in the space-time metric destroys the
commutativity (and hence locality) of position measurement operators.Comment: LA-UR-93-2890-REV, "honorable mention" for the 1994 Awards by Gravity
Research Foundatio
Probing Quantum Aspects of Gravity
We emphasize that a specific aspect of quantum gravity is the absence of a
super-selection rule that prevents a linear superposition of different
gravitational charges. As an immediate consequence, we obtain a tiny, but
observable, violation of the equivalence principle, provided, inertial and
gravitational masses are not assumed to be operationally identical objects. In
this framework, the cosmic gravitational environment affects local experiments.
A range of terrestrial experiments, from neutron interferometry to neutrino
oscillations, can serve as possible probes to study the emergent quantum
aspects of gravity.Comment: Phys. Lett. B (in press). S. Sarkar's name was inadvertently missed
from the list of authors for "Nature 393 (1998) 763-765." This has been now
correcte
L/E-Flatness of the Electron-Like Event Ratio in Super-Kamiokande and a Degeneracy in Neutrino Masses
We show that the L/E-flatness of the electron-like event ratio in the
Super-Kamiokande atmospheric neutrino data implies the equality of the
expectation values for the muon and tau neutrino masses. We establish this
result by obtaining a set of three constraints on the neutrino-oscillation
mixing matrix as contained in the indicated flatness. The resulting 3x3
neutrino-oscillation matrix depends only on one angle. A remarkable result that
follows directly from this matrix is the consistency between the mixing angles
observed by LSND and Super-Kamiokande.Comment: Journal versio
Wave-Particle duality at the Planck scale: Freezing of neutrino oscillations
A gravitationally-induced modification to de Broglie wave-particle duality is
presented. At Planck scale, the gravitationally-modified matter wavelength
saturates to a few times the Planck length in a momentum independent manner. In
certain frameworks, this circumstance freezes neutrino oscillations in the
Planck realm. This effect is apart, and beyond, the gravitational red-shift. A
conclusion is drawn that in a complete theory of quantum gravity the notions of
``quantum'' and ``gravity'' shall carry new meanings -- meanings, that are yet
to be deciphered from theory and observations in their entirety.Comment: Published versio
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
Heavy sterile neutrinos: Bounds from big-bang nucleosynthesis and SN 1987A
Cosmological and astrophysical effects of heavy (10 - 200 MeV) sterile Dirac
neutrinos, mixed with the active ones, are considered. The bounds on mass and
mixing angle from both supernovae and big-bang nucleosynthesis are presented.Comment: 19 pages, 5 figures, 1 table. Some references adde
Very special relativity as relativity of dark matter: the Elko connection
In the very special relativity (VSR) proposal by Cohen and Glashow, it was
pointed out that invariance under HOM(2) is both necessary and sufficient to
explain the null result of the Michelson-Morely experiment. It is the quantum
field theoretic demand of locality, or the requirement of P, T, CP, or CT
invariance, that makes invariance under the Lorentz group a necessity.
Originally it was conjectured that VSR operates at the Planck scale; we propose
that the natural arena for VSR is at energies similar to the standard model,
but in the dark sector. To this end we provide an ab initio spinor
representation invariant under the SIM(2) avatar of VSR and construct a mass
dimension one fermionic quantum field of spin one half. This field turns out to
be a very close sibling of Elko and it exhibits the same striking property of
intrinsic darkness with respect to the standard model fields. In the new
construct, the tension between Elko and Lorentz symmetries is fully resolved.
We thus entertain the possibility that the symmetries underlying the standard
model matter and gauge fields are those of Lorentz, while the event space
underlying the dark matter and the dark gauge fields supports the algebraic
structure underlying VSR.Comment: 19 pages. Section 5 is new. Published version (modulo a footnote, and
a corrected typo
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