37 research outputs found
Radiatively Induced Breaking of Conformal Symmetry in a Superpotential
Radiatively induced symmetry breaking is considered for a toy model with one
scalar and one fermion field unified in a superfield. It is shown that the
classical quartic self-interaction of the superfield possesses a quantum
infrared singularity. Application of the Coleman-Weinberg mechanism for
effective potential leads to the appearance of condensates and masses for both
scalar and fermion components. That induces a spontaneous breaking of the
initial classical symmetries: the supersymmetry and the conformal one. The
energy scales for the scalar and fermion condensates appear to be of the same
order, while the renormalization scale is many orders of magnitude higher. A
possibility to relate the considered toy model to conformal symmetry breaking
in the Standard Model is discussed.Comment: Improved final version with new references and misprints corrected, 9
pages , no figure
Charge without charge, regular spherically symmetric solutions and the Einstein-Born-Infeld theory
The aim of this paper is to continue the research of JMP 46, 042501 (2005) of
regular static spherically symmetric spacetimes in Einstein-Born-Infeld
theories from the point of view of the spacetime geometry and the
electromagnetic structure. The energy conditions, geodesic completeness and the
main features of the horizons of this spacetime are explicitly shown. A new
static spherically symmetric dyonic solution in Einstein-Born-Infeld theory
with similar good properties as in the regular pure electric and magnetic cases
of our previous work, is presented and analyzed. Also, the circumvention of a
version of "no go" theorem claiming the non existence of regular electric black
holes and other electromagnetic static spherically configurations with regular
center is explained by dealing with a more general statement of the problem.Comment: Figures in Int J Theor Phys (Online First
New spherically symmetric monopole and regular solutions in Einstein-Born-Infeld theories
In this work a new asymptotically flat solution of the coupled
Einstein-Born-Infeld equations for a static spherically symmetric space-time is
obtained. When the intrinsic mass is zero the resulting spacetime is regular
everywhere, in the sense given by B. Hoffmann and L. Infeld in 1937, and the
Einstein-Born-Infeld theory leads to the identification of the gravitational
with the electromagnetic mass. This means that the metric, the electromagnetic
field and their derivatives have not discontinuities in all the manifold. In
particular, there are not conical singularities at the origin, in contrast to
well known monopole solution studied by B. Hoffmann in 1935. The lack of
uniqueness of the action function in Non-Linear-Electrodynamics is discussed.Comment: Final version in journal. Amplied version with new results that
previous talk in Protvino worksho
The Affine Structure of Gravitational Theories: Symplectic Groups and Geometry
We give a geometrical description of gravitational theories from the
viewpoint of symmetries and affine structure. We show how gravity, considered
as a gauge theory, can be consistently achieved by the nonlinear realization of
the conformal-affine group in an indirect manner: due the partial isomorphism
between and the centrally extended ,
we perform a nonlinear realization of the centrally extended (CE) in its semi-simple version. In particular, starting from the bundle
structure of gravity, we derive the conformal-affine Lie algebra and then, by
the non-linear realization, we define the coset field transformations, the
Cartan forms and the inverse Higgs constraints. Finally we discuss the
geometrical Lagrangians where all the information on matter fields and their
interactions can be contained.Comment: 21 pages. arXiv admin note: text overlap with arXiv:0910.2881,
arXiv:0705.460
The Newman-Janis Algorithm, Rotating Solutions and Einstein-Born-Infeld Black Holes
A new metric is obtained by applying a complex coordinate trans- formation to
the static metric of the self-gravitating Born-Infeld monopole. The behaviour
of the new metric is typical of a rotating charged source, but this source is
not a spherically symmetric Born-Infeld monopole with rotation. We show that
the structure of the energy-momentum tensor obtained with this new metric does
not correspond to the typical structure of the energy momentum tensor of
Einstein-Born-Infeld theory induced by a rotating spherically symmetric source.
This also show, that the complex coordinate transformations have the
interpretation given by Newman and Janis only in space-time solutions with
linear sources
Von Neumann's Quantization of General Relativity
Von Neumann's procedure is applied for quantization of General Relativity. We
quantize the initial data of dynamical variables at the Planck epoch, where the
Hubble parameter coincides with the Planck mass. These initial data are defined
via the Fock simplex in the tangent Minkowskian space-time and the Dirac
conformal interval. The Einstein cosmological principle is applied for the
average of the spatial metric determinant logarithm over the spatial volume of
the visible Universe. We derive the splitting of the general coordinate
transformations into the diffeomorphisms (as the object of the second N\"other
theorem) and the initial data transformations (as objects of the first N\"other
theorem). Following von Neumann, we suppose that the vacuum state is a quantum
ensemble. The vacuum state is degenerated with respect to quantum numbers of
non-vacuum states with the distribution function that yields the Casimir effect
in gravidynamics in analogy to the one in electrodynamics. The generation
functional of the perturbation theory in gravidynamics is given as a solution
of the quantum energy constraint. We discuss the region of applicability of
gravidynamics and its possible predictions for explanation of the modern
observational and experimental data.Comment: 14 pages, updated version with extended discussio
Non-compact Groups, Coherent States, Relativistic Wave Equations and the Harmonic Oscillator II: Physical and Geometrical Considerations
The physical meaning of the particularly simple non-degenerate supermetric,
introduced in the previous part by the authors, is elucidated and the possible
connection with processes of topological origin in high energy physics is
analyzed and discussed. New possible mechanism of the localization of the
fields in a particular sector of the supermanifold is proposed and the
similarity and differences with a 5-dimensional warped model are shown. The
relation with gauge theories of supergravity based in the group is
explicitly given and the possible original action is presented. We also show
that in this non-degenerate super-model the physic states, in contrast with the
basic states, are observables and can be interpreted as tomographic projections
or generalized representations of operators belonging to the metaplectic group
. The advantage of geometrical formulations based on non-degenerate
super-manifolds over degenerate ones is pointed out and the description and the
analysis of some interesting aspects of the simplest Riemannian superspaces are
presented from the point of view of the possible vacuum solutions.Comment: Stile of the text improved in Journa
Microcanonical treatment of black hole decay at the Large Hadron Collider
This study of corrections to the canonical picture of black hole decay in
large extra dimensions examines the effects of back-reaction corrected and
microcanonical emission at the LHC. We provide statistical interpretations of
the different multiparticle number densities in terms of black hole decay to
standard model particles. Provided new heavy particles of mass near the
fundamental Planck scale are not discovered, differences between these
corrections and thermal decay will be insignificant at the LHC.Comment: small additions and clarifications, format for J. Phys.
Electrified BPS Giants: BPS configurations on Giant Gravitons with Static Electric Field
We consider D3-brane action in the maximally supersymmetric type IIB
plane-wave background. Upon fixing the light-cone gauge, we obtain the
light-cone Hamiltonian which is manifestly supersymmetric. The 1/2 BPS
solutions of this theory (solutions which preserve 16 supercharges) are either
of the form of spherical three branes, the giant gravitons, or zero size point
like branes. We then construct specific classes of 1/4 BPS solutions of this
theory in which static electric field on the brane is turned on. These
solutions are deformations about either of the two 1/2 BPS solutions. In
particular, we study in some detail 1/4 BPS configurations with electric dipole
on the three sphere giant, i.e. BIons on the giant gravitons, which we hence
call BIGGons. We also study BPS configurations corresponding to turning on a
background uniform constant electric field. As a result of this background
electric field the three sphere giant is deformed to squashed sphere, while the
zero size point like branes turn into circular or straight fundamental strings
in the plane-wave background, with their tension equal to the background
electric field.Comment: 32 pages, 1 eps figure; v2: Presentation of derivation of light-cone
Hamiltonian improved, Refs adde