393 research outputs found
On bi-hamiltonian structure of some integrable systems on so*(4)
We classify all the quadratic Poisson structures on and ,
which have the same foliation by symplectic leaves as the canonical Lie-Poisson
tensors. The separated variables for the some of the corresponding
bi-integrable systems are constructed.Comment: LaTeX with Amsfonts, 13 pages, corrected typo
On the Crepant Resolution Conjecture in the Local Case
In this paper we analyze four examples of birational transformations between
local Calabi-Yau 3-folds: two crepant resolutions, a crepant partial
resolution, and a flop. We study the effect of these transformations on
genus-zero Gromov-Witten invariants, proving the
Coates-Corti-Iritani-Tseng/Ruan form of the Crepant Resolution Conjecture in
each case. Our results suggest that this form of the Crepant Resolution
Conjecture may also hold for more general crepant birational transformations.
They also suggest that Ruan's original Crepant Resolution Conjecture should be
modified, by including appropriate "quantum corrections", and that there is no
straightforward generalization of either Ruan's original Conjecture or the
Cohomological Crepant Resolution Conjecture to the case of crepant partial
resolutions. Our methods are based on mirror symmetry for toric orbifolds.Comment: 27 pages. This is a substantially revised and shortened version of my
preprint "Wall-Crossings in Toric Gromov-Witten Theory II: Local Examples";
all results contained here are also proved there. To appear in Communications
in Mathematical Physic
Deuteron frozen spin polarized target for nd experiements at the VdG accelerator of Charles University
A frozen spin polarized deuteron target cooled by the 3He/4He dilution
refrigerator is described. Fully deuterated 1,2-propanediol was used as a
target material. Deuteron vector polarization about 40% was obtained for the
target in the shape of a cylinder of 2 cm diameter and 6 cm length. The target
is intended for a study of 3N interactions at the polarized neutron beam
generated by the Van de Graaff accelerator at the Charles University in Prague
The Spinning Particles as a Nonlinear Realizations of the Superworldline Reparametrization Invariance
The superdiffeomorphisms invariant description of - extended spinning
particle is constructed in the framework of nonlinear realizations approach.
The action is universal for all values of and describes the time evolution
of different group elements of the superdiffeomorphisms group of the
superspace. The form of this action coincides with the one-dimensional
version of the gravity action, analogous to Trautman's one.Comment: 4 pages, RevTe
Sensitivity on Earth Core and Mantle densities using Atmospheric Neutrinos
Neutrino radiography may provide an alternative tool to study the very deep
structures of the Earth. Though these measurements are unable to resolve the
fine density layer features, nevertheless the information which can be obtained
are independent and complementary to the more conventional seismic studies. The
aim of this paper is to assess how well the core and mantle averaged densities
can be reconstructed through atmospheric neutrino radiography. We find that
about a 2% sensitivity for the mantle and 5% for the core could be achieved for
a ten year data taking at an underwater km^3 Neutrino Telescope. This result
does not take into account systematics related to the details of the
experimental apparatus.Comment: 11 pages, 11 figures, accepted for publication in JCA
Nonlinear Realization of N=2 Superconformal Symmetry and Brane Effective Actions
Due to the incompatibility of the nonlinear realization of superconformal
symmetry and dilatation symmetry with the dilaton as the compensator field, in
the present paper it shows an alternative mechanism of spontaneous breaking the
N=2 superconformal symmetry to the N=0 case. By using the approach of nonlinear
transformations it is found that it leads to a space-filling brane theory with
Weyl scale W(1,3) symmetry. The dynamics of the resulting Weyl scale invariant
brane, along with that of other Nambu-Goldstone fields, is derived in terms of
the building blocks of the vierbein and the covariant derivative from the
Maurer-Cartan oneforms. A general coupling of the matter fields localized on
the brane world volume to these NG fields is also constructed.Comment: 22 pages, more references and comments are adde
AdS/CFT Equivalence Transformation
We show that any conformal field theory in d-dimensional Minkowski space, in
a phase with spontaneously broken conformal symmetry and with the dilaton among
its fields, can be rewritten in terms of the static gauge (d-1)-brane on
AdS_(d+1) by means of an invertible change of variables. This nonlinear
holographic transformation maps the Minkowski space coordinates onto the brane
worldvolume ones and the dilaton onto the transverse AdS brane coordinate. One
of the consequences of the existence of this map is that any (d-1)-brane
worldvolume action on AdS_(d+1)\times X^m (with X^m standing for the sphere S^m
or more complicated curved manifold) admits an equivalent description in
Minkowski space as a nonlinear and higher-derivative extension of some
conventional conformal field theory action, with the conformal group being
realized in a standard way. The holographic transformation explicitly relates
the standard realization of the conformal group to its field-dependent
nonlinear realization as the isometry group of the brane AdS_(d+1) background.
Some possible implications of this transformation, in particular, for the study
of the quantum effective action of N=4 super Yang-Mills theory in the context
of AdS/CFT correspondence, are briefly discussed.Comment: LaTeX, 19 pages, minor correction in Abstrac
Generalized E(7(7)) coset dynamics and D=11 supergravity
The hidden on-shell E(7(7)) symmetry of maximal supergravity is usually
discussed in a truncation from D=11 to four dimensions. In this article, we
reverse the logic and start from a theory with manifest off-shell E(7(7))
symmetry inspired by West's coset construction. Following de Wit's and
Nicolai's idea that a 4+56 dimensional "exceptional geometry" underlies maximal
supergravity, we construct the corresponding Lagrangian and the supersymmetry
variations for the 56 dimensional subsector. We prove that both the dynamics
and the supersymmetry coincide with D=11 supergravity in a truncation to d=7 in
the expected way.Comment: 42 pages, v2: references adde
Gravitation and inertia; a rearrangement of vacuum in gravity
We address the gravitation and inertia in the framework of 'general gauge
principle', which accounts for 'gravitation gauge group' generated by hidden
local internal symmetry implemented on the flat space. We connect this group to
nonlinear realization of the Lie group of 'distortion' of local internal
properties of six-dimensional flat space, which is assumed as a toy model
underlying four-dimensional Minkowski space. The agreement between proposed
gravitational theory and available observational verifications is satisfactory.
We construct relativistic field theory of inertia and derive the relativistic
law of inertia. This theory furnishes justification for introduction of the
Principle of Equivalence. We address the rearrangement of vacuum state in
gravity resulting from these ideas.Comment: 17 pages, no figures, revtex4, Accepted for publication in Astrophys.
Space Sc
Deriving the mass of particles from Extended Theories of Gravity in LHC era
We derive a geometrical approach to produce the mass of particles that could
be suitably tested at LHC. Starting from a 5D unification scheme, we show that
all the known interactions could be suitably deduced as an induced symmetry
breaking of the non-unitary GL(4)-group of diffeomorphisms. The deformations
inducing such a breaking act as vector bosons that, depending on the
gravitational mass states, can assume the role of interaction bosons like
gluons, electroweak bosons or photon. The further gravitational degrees of
freedom, emerging from the reduction mechanism in 4D, eliminate the hierarchy
problem since generate a cut-off comparable with electroweak one at TeV scales.
In this "economic" scheme, gravity should induce the other interactions in a
non-perturbative way.Comment: 30 pages, 1 figur
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