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J. Lukierski

Publications and source records attributed to J. Lukierski.

At least 37 records · Page 2Linked to original sources

Gravity on de-Sitter 3-Brane, Induced Einstein-Hilbert Term and Massless Gravitons

We study the extensions of DGP model which are described by five-dimensional Einstein gravity coupled covariantly to 3-brane with induced gravity term and consider warped D=4 de Sitter background field solutions on the brane. The case with included D=5 AdS cosmological term is also considered. Following background field method we obtain the field equations described by the Lagrangean terms bilinear in gravitational field. In such a linear field approximation on curved dS background we calculate explicitly the five-dimensional massive terms as well as the mass-like ones on the brane. We investigate the eigenvalue problem of Schrödinger-like equation in fifth dimension for graviton masses and discuss the existence of massless as well as massive graviton modes in the bulk and on the brane without and with induced gravity.

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Galilean Exotic Planar Supersymmetries and Nonrelativistic Supersymmetric Wave Equations

We describe the general class of $N$-extended $D=(2+1)$ Galilean supersymmetries obtained, respectively, from the $N$-extended D=3 Poincaré superalgebras with maximal sets of central charges. We confirm the consistency of supersymmetry with the presence of the `exotic' second central charge $θ$. We show further how to introduce a N=2 Galilean superfield equation describing nonrelativistic spin 0 and spin 1/2 free particles.

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Massless higher spin D=4 superparticle with both N=1 supersymmetry and its bosonic counterpart

We show that the massless higher spin four-dimensional particle model with bosonic counterpart of N=1 supersymmetry respects SU(3,2) invariance. We extend this particle model to a superparticle possessing $SU(3,2|1)$ supersymmetry which is a closure of standard four-dimensional N=1 superconformal symmetry $SU(2,2|1)$ and its bosonic SU(3,2) counterpart. The new massless higher spin D=4 superparticle model describes trajectories in Minkowski superspace $(x^μ, θ^α, \barθ^{\dotα})$ extended by the commuting Weyl spinor $ζ^α$, $\barζ^{\dotα}=(ζ^α)^\ast$. We find the relevant phase space constraints and quantize the model. As a result of quantization we obtain the superwave function which describes an infinite sequence of four-dimensional massless chiral superfields with arbitrary external helicity indices.

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Jordanian Twist Quantization of D=4 Lorentz and Poincare Algebras and D=3 Contraction Limit

We describe in detail two-parameter nonstandard quantum deformation of D=4 Lorentz algebra $\mathfrak{o}(3,1)$, linked with Jordanian deformation of $\mathfrak{sl} (2;\mathbb{C})$. Using twist quantization technique we obtain the explicit formulae for the deformed coproducts and antipodes. Further extending the considered deformation to the D=4 Poincaré algebra we obtain a new Hopf-algebraic deformation of four-dimensional relativistic symmetries with dimensionless deformation parameter. Finally, we interpret $\mathfrak{o}(3,1)$ as the D=3 de-Sitter algebra and calculate the contraction limit $R\to\infty$ ($R$ -- de-Sitter radius) providing explicit Hopf algebra structure for the quantum deformation of the D=3 Poincaré algebra (with masslike deformation parameters), which is the two-parameter light-cone $κ$-deformation of the D=3 Poincaré symmetry.

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Twisted Space-Time Symmetry, Non-Commutativity and Particle Dynamics

We describe the twisted space-time symmetries which imply the quantum Poincaré covariance of noncommutative Minkowski spaces, with constant, Lie algebraic and quadratic commutators. Further we present the relativistic and nonrelativistic particle models invariant respectively under twisted relativistic and twisted Galilean symmetries.

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Exotic Galilean Conformal Symmetry and its Dynamical Realisations

The six-dimensional exotic Galilean algebra in (2+1) dimensions with two central charges $m$ and $θ$, is extended when $m=0$, to a ten-dimensional Galilean conformal algebra with dilatation, expansion, two acceleration generators and the central charge $θ$. A realisation of such a symmetry is provided by a model with higher derivatives recently discussed in \cite{peterwojtek}. We consider also a realisation of the Galilean conformal symmetry for the motion with a Coulomb potential and a magnetic vortex interaction. Finally, we study the restriction, as well as the modification, of the Galilean conformal algebra obtained after the introduction of the minimally coupled constant electric and magnetic fields.

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New Lie-Algebraic and Quadratic Deformations of Minkowski Space from Twisted Poincare Symmetries

We consider two new classes of twisted D=4 quantum Poincaré symmetries described as the dual pairs of noncocommutative Hopf algebras. Firstly we investigate a two-parameter class of twisted Poincaré algebras which provide the examples of Lie-algebraic noncommutativity of the translations. The corresponding associative star-products and new deformed Lie-algebraic Minkowski spaces are introduced. We discuss further the twist deformations of Poincaré symmetries generated by the twist with its carrier in Lorentz algebra. We describe corresponding deformed Poincaré group which provides the quadratic deformations of translation sector and define the quadratically deformed Minkowski space-time algebra.

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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.

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Massive Relativistic Particle Models with Bosonic Counterpart of Supersymmetry

We consider the massive relativistic particle models on fourdimensional Minkowski space extended by $N$ commuting Weyl spinors for N=1 and N=2. The N=1 model is invariant under the most general form of bosonic counterpart of simple D=4 supersymmetry, and provides after quantization the bosonic counterpart of chiral superfields, satisfying Klein--Gordon equation. In massless case these fields do satisfy the Fierz-Pauli equations. For N=2 we obtain after quantization the free massive higher spin fields for arbitrary spin satisfying linear Bargman--Wigner equations. Finally the problem of statistics in presented framework for half--integer classical spin fields is discussed.

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On Twist Quantizations of D=4 Lorentz and Poincare Algebras

We use the decomposition of o(3,1)=sl(2;C)_1\oplus sl(2;C)_2 in order to describe nonstandard quantum deformation of o(3,1) linked with Jordanian deformation of sl(2;C}. Using twist quantization technique we obtain the deformed coproducts and antipodes which can be expressed in terms of real physical Lorentz generators. We describe the extension of the considered deformation of D=4 Lorentz algebra to the twist deformation of D=4 Poincare algebra with dimensionless deformation parameter.

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Basic Twist Quantization of the Exceptional Lie Algebra G_2

We present the formulae for twist quantization of $g_2$, corresponding to the solution of classical YB equation with support in the 8-dimensional Borel subalgebra of $g_2$. The considered chain of twists consists of the four factors describing the four steps of quantization: Jordanian twist, the two twist factors extending Jordanian twist and the deformed Jordanian or in second variant additional Abelian twist. The first two steps describe as well the $sl(3)$ quantization. The coproducts are calculated for each step in explicite form, and for that purpose we present new formulas for the calculation of similarity transformations on tensor product. We introduce new basic generators in universal enveloping algebra $U(g_2)$ which provide nonlinearities in algebraic sector maximally simplifying the deformed coproducts.

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Jordanian Quantum Deformations of D=4 Anti-de-Sitter and Poincare Superalgebras

We consider a superextension of the extended Jordanian twist, describing nonstandard quantization of anti-de-Sitter ($AdS$) superalgebra $osp(1|4)$ in the form of Hopf superalgebra. The super-Jordanian twisting function and corresponding basic coproduct formulae for the generators of $osp(1|4)$ are given in explicit form. The nonlinear transformation of the classical superalgebra basis not modifying the defining algebraic relations but simplifying coproducts and antipodes is proposed. Our physical application is to interpret the new super-Jordanian deformation of $osp(1|4)$ superalgebra as deformed D=4 $AdS$ supersymmetries. Subsequently we perform suitable contraction of quantum Jordanian $AdS$ superalgebra and obtain new $κ$-deformation of D=4 Poincare superalgebra, with the bosonic sector describing the light cone $κ$-deformation of Poincare symmetries.

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Two-parameter extensions of the κ-Poincaré quantum deformation

We consider the extensions of classical r-matrix for κ-deformed Poincaré algebra which satisfy modified Yang-Baxter equation. Two examples introducing additional deformation parameter (dimensionfull \frac{1}{\widetildeκ} or dimensionless ξ) are presented. We describe the corresponding quantization (two-parameter κ-Poincaré quantum Hopf algebras) in explicite form as obtained by twisting of standard κ-deformed framework. In the second example quantum twist function depends on nonclassical generators, with κ-deformed coproduct. Finally we mention also the ``soft'' twists with carrier in fourmomenta sector.

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Two-Twistor Space, Commuting Composite Minkowski Coordinates and Particle Dynamics

We employ the modification of the basic Penrose formula in twistor theory, which allows to introduce commuting composite space-time coordinates. It appears that in the course of such modification the internal symmetry SU(2) of two-twistor system is broken to U(1). We consider the symplectic form on two-twistor space, permitting to interpret its 16 real components as a phase-space. After a suitable change of variables such a two-twistor phase space is split into three mutually commuting parts, describing respectively the standard relativistic phase space (8 degrees of freedom), the spin sector (6 degrees of freedom) and the canonical pair angle-charge describing the electric charge sector (2 degrees of freedom). We obtain a geometric framework providing a twistor-inspired 18-dimensional extended relativistic phase space $\mathcal{M}^{18}$. In such a space we propose the action only with first class constraints, describing the relativistic particle characterized by mass, spin and electric charge.

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N=2 Supersymmetric Planar Particles and Magnetic Interaction from Noncommutativity

We describe a N=2 supersymmetric extension of the nonrelativistic (2+1)-dimensional model describing particles on the noncommutative plane with scalar (electric) and vector (magnetic) interactions. First, we employ the N=2 superfield technique and show that in the presence of a scalar N=2 superpotential the magnetic interaction is implied by the presence of noncommutativity of position variables. Further, by expressing the supersymmetric Hamiltonian as a bilinear in N=2 supercharges we obtain two supersymmetric models with electromagnetic interactions and two different noncanonical symplectic structures describing noncommutativity. We show that both models are related by a map of the Seiberg-Witten type.

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Massive Relativistic Particle Model with Spin and Electric Charge from Two-Twistor Dynamics

The sixteen real coordinates of two-twistor space are transformed by a nonlinear mapping into an enlarged space-time framework. The standard relativistic phase space of coordinates $(X_μ, P_μ)$ is supplemented by a six-parameter spin phase manifold (two pairs $(η_α,σ_α)$ and $(\barη_{\dotα}, \barσ_{\dotα})$ of canonically conjugated Weyl spinors constrained by two second class constraints) and the electric charge phase space ($e,ϕ$). The free two-twistor classical mechanics is rewritten in this enlarged relativistic phase space as a model for a relativistic particle. Definite values for the mass, spin and the electric charge of the particle are introduced by means of three first class constraints.

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