338 research outputs found
Extension of the Shirafuji model for Massive Particles with Spin
We extend the Shirafuji model for massless particles with primary spacetime
coordinates and composite four-momenta to a model for massive particles with
spin and electric charge. The primary variables in the model are the spacetime
four-vector, four scalars describing spin and charge degrees of freedom as well
as a pair of Weyl spinors. The geometric description proposed in this paper
provides an intermediate step between the free purely twistorial model in
two-twistor space in which both spacetime and four-momenta vectors are
composite, and the standard particle model, where both spacetime and
four-momenta vectors are elementary. We quantize the model and find explicitly
the first-quantized wavefunctions describing relativistic particles with mass,
spin and electric charge. The spacetime coordinates in the model are not
commutative; this leads to a wavefunction that depends only on one covariant
projection of the spacetime four-vector (covariantized time coordinate)
defining plane wave solutions.Comment: Latex, 27 pages, appendix.sty, newlfont.sty (attached
Energy efficiency in buildings as one of the solutions for achieving energy security
Energy is essential for economic development, food production and global security. According to the UN, the world will need at least 45% more energy by 2030.
It is well known that resources we are using today for the energy production have very negative impact on the planet, especially for the climate change. Alternative resources that are renewable and don't have CO2 emission also have own disadvantages. For example, solar panels are quite expensive, depend on climate, need a lot of place and also there is a big issue with utilization of panels in the end of their life cycle. Wind farmas and hydroelectric power stations are located to far from consumers and transmission looses are very high in these cases. Indeed, in future scientists will solve these problems, but so far we have to deal with them. It means that the best solution would be to combine alternative energy resources and energy saving.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3606
Master Higher-Spin Particle
We propose a "master" higher-spin (HS) particle system. The particle model
relevant to the unfolded formulation of HS theory, as well as the HS particle
model with a bosonic counterpart of supersymmetry, follow from the master model
as its two different gauges. Quantization of the master system gives rise to a
new form of the massless HS equations in an extended space involving, besides
extra spinorial coordinates, also a complex scalar one. As solutions to these
equations we recover the massless HS multiplet with fields of all integer and
half-integer helicities, and obtain new multiplets with a non-zero minimal
helicity. The HS multiplets are described by complex wave functions which are
holomorphic in the scalar coordinate and carry an extra U(1) charge q. The
latter fully characterizes the given multiplet by fixing the minimal helicity
as q/2. We construct a twistorial formulation of the master system and present
the general solution of the associate HS equations through an unconstrained
twistor "prepotential".Comment: 21 pages, minor corrections, version to appear in Class. Quantum Gra
New Model of Higher-Spin Particle
We elaborate on a new model of the higher-spin (HS) particle which makes
manifest the classical equivalence of the HS particle of the unfolded
formulation and the HS particle model with a bosonic counterpart of
supersymmetry. Both these models emerge as two different gauges of the new
master system. Physical states of the master model are massless HS multiplets
described by complex HS fields which carry an extra U(1) charge q. The latter
fully characterizes the given multiplet by fixing the minimal helicity as q/2.
We construct the twistorial formulation of the master model and discuss
symmetries of the new HS multiplets within its framework.Comment: 13 pages, talk given by E. Ivanov at the XII International Conference
on Symmetry Methods in Physics (SYMPHYS-XII), Yerevan, Armenia, July 03 - 08,
2006; to be published in the Proceeding
Two-twistor particle models and free massive higher spin fields
We present D=3 and D=4 models for massive particles moving in a new type of
enlarged spacetime, with D-1 additional vector coordinates, which after
quantization lead to the towers of massive higher spin (HS) free fields. Two
classically equivalent formulations are presented: one with a hybrid
spacetime/bispinor geometry and a second described by a free two-twistor
dynamics with constraints. After quantization in the D=3 and D=4 cases, the
wave functions are given as functions on the SL(2,R) and SL(2,C) group
manifolds respectively, and describe arbitrary on-shell momenta and spin
degrees of freedom. Finally, the D=6 case and possible supersymmetric
extensions are mentioned.Comment: 37 pages, plain latex, v2. Text in Secs. 1 nd 4 enlarged, references
added. Version to appear in JHE
Seed size in lentil: iMapping at the U of S
Non-Peer Reviewe
Bi-HKT and bi-Kaehler supersymmetric sigma models
We study CKT (or bi-HKT) N = 4 supersymmetric quantum mechanical sigma
models. They are characterized by the usual and the mirror sectors displaying
each HKT geometry. When the metric involves isometries, a Hamiltonian reduction
is possible. The most natural such reduction with respect to a half of bosonic
target space coordinates produces an N = 4 model, related to the twisted
Kaehler model due to Gates, Hull and Rocek, but including certain extra F-terms
in the superfield action.Comment: 31 pages, minor corrections in the published versio
Seed size in lentil: iMapping at the U of S
Non-Peer Reviewe
- …