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S. Fedoruk

Publications and source records attributed to S. Fedoruk.

18 recordsLinked to original sources

Towards Lagrangian construction for infinite half-integer spin field

We formulate the conditions for the generalized fields in the space with additional commuting Weyl spinor coordinates which define the infinite half-integer spin representation of the four-dimensional Poincaré group. Using this formulation we develop the BRST approach and derive the Lagrangian for the half-integer infinite spin fields.

hep-th

Supersymmetric Calogero models from superfield gauging

Using the superfield gauging procedure, we construct new ${\cal N}\,{=}\,2$ and ${\cal N}\,{=}\,4$ superfield systems that generalize Calogero models. In the bosonic limit, these systems yield rational Calogero models and hyperbolic Calogero-Sutherland models in the ${\cal N}\,{=}\,2$ case, and their ${\rm U}(2)$ spin generalization in the ${\cal N}\,{=}\,4$ case.

hep-th

Massless infinite spin (super)particles and fields

A new twistorial field formulation of a massless infinite spin particle is derived. We find a twistorial infinite spin field and derive its helicity decomposition. The twistorial equations of motion for infinite spin fields in the cases of integer and half-integer helicities are derived. We show that the infinite integer-spin field and infinite half-integer-spin field form the $\mathcal{N}{=}\,1$ infinite spin supermultiplet. The corresponding supersymmetry transformations are presented. We prove that the supersymmetry algebra is closed on-shell.

hep-th

Covariant Quantization of d=4 Brink-Schwarz Superparticle with Lorentz Harmonics

Covariant first and second quantization of the free d=4 massless superparticle are implemented with the introduction of purely gauge auxiliary spinor Lorentz harmonics. It is shown that the general solution of the condition of maslessness is a sum of two independent chiral superfields with each of them corresponding to finite superspin. A translationally covariant, in general bijective correspondence between harmonic and massless superfields is constructed. By calculation of the commutation function it is shown that in the considered approach only harmonic fields with correct connection between spin and statistics and with integer negative homogeneity index satisfy the microcausality condition. It is emphasized that harmonic fields that arise are reducible at integer points. The index spinor technique is used to describe infinite-component fields of finite spin; the equations of motion of such fields are obtained, and for them Weinberg's theorem on the connection between massless helicity particles and the type of nongauge field that describes them is generalized.

hep-th

Twistorial and space-time descriptions of massless infinite spin (super)particles and fields

We develop a new twistorial field formulation of a massless infinite spin particle. Unlike our previous approach arXiv:1805.09706, the quantization of such a world-line infinite spin particle model is carried without any gauge fixing. As a result, we construct a twistorial infinite spin field and derive its helicity decomposition. Using the field twistor transform, we construct the space-time infinite (continuous) spin field, which depends on the coordinate four-vector and additional commuting Weyl spinor. The equations of motion for infinite spin fields in the cases of integer and half-integer helicities are derived. We show that the infinite integer-spin field and infinite half-integer-spin field form the $\mathcal{N}{=}\,1$ infinite spin supermultiplet. The corresponding supersymmetry transformations are formulated and their on-shell algebra is derived. As a result, we find the field realization of the infinite spin $\mathcal{N}{=}\,1$ supersymmetry.

hep-th

Model of massless relativistic particle with continuous spin and its twistorial description

We propose a new world-line Lagrangian model of the D=4 massless relativistic particle with continuous spin and develop its twistorial formulation. The description uses two Penrose twistors subjected to four first class constraints. After the first quantization of the world-line twistorial model, the wave function is defined by an unconstrained function on the two-dimensional complex affine plane. We find the twistor transform that determines the space-time field of the continuous spin particle through the corresponding twistor one, which plays the role of a prepotential. It is shown that this space-time field is an exact solution of the space-time constraints defining the irreducible massless representation of the Poincare group with continuous spin.

hep-th

Generic HKT geometries in the harmonic superspace approach

We explain how a generic HKT geometry can be derived using the language of N = 4 supersymmetric quantum mechanics. To this end, one should consider a Lagrangian involving several (4,4,0) multiplets defined in harmonic superspace and subject to nontrivial harmonic constraints. Conjecturally, this general construction worked out earlier by Delduc and Ivanov gives a complete classification of all HKT geometries. Each such geometry is generated by two different functions (potentials) of a special type that depend on harmonic superfields and on harmonics. Given these two potentials, one can derive the vielbeins, metric, connections and curvatures, but this is not so simple: one should solve rather complicated differential equations. We illustrate the general construction by giving a detailed derivation of the metric for the hyper-Kaehler Taub-NUT manifold. In the generic case, we arrive at an HKT geometry. In this paper, we give a simple proof of this assertion.

hep-th

New realizations of the supergroup D(2,1;α) in N=4 superconformal mechanics

We present new explicit realizations of the most general N=4, d=1 superconformal symmetry D(2,1;α) in the models of N=4 superconformal mechanics based on the reducible multiplets (1,4,3)\oplus(0,4,4), (3,4,1)\oplus(0,4,4) and (4,4,0)\oplus(0,4,4). We start from the manifestly supersymmetric superfield actions for these systems and then descend to the relevant off- and on-shell component actions from which we derive the D(2,1;α) (super)charges by the Noether procedure. Some peculiarities of these realizations of D(2,1;α) are discussed. We also construct a new D(2,1;α) invariant system by joining the multiplets (3,4,1) and (4,4,0) in such a way that they interact with each other through an extra (0,4,4) multiplet. New fermionic conformal couplings appear as the result of elimination of the appropriate auxiliary fields.

hep-th

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.

hep-th

Nonrelativistic counterparts of twistors and the realizations of Galilean conformal algebra

Using the notion of Galilean conformal algebra (GCA) in arbitrary space dimension d, we introduce for d=3 quantized nonrelativistic counterpart of twistors as the spinorial representation of O(2,1){\oplus}SO(3) which is the maximal semisimple subalgebra of three-dimensional GCA. The GC-covariant quantization of such nonrelativistic spinors, which shall be called also Galilean twistors, is presented. We consider for d=3 the general spinorial matrix realizations of GCA, which are further promoted to quantum-mechanical operator representations, expressed as bilinears in quantized Galilean twistors components. For arbitrary Hermitian quantum-mechanical Galilean twistor realizations we obtain the result that the representations of GCA with positive-definite Hamiltonian do not exist. For non-positive H we construct for N{\geq}2 the Hermitian Galilean N-twistor realizations of GCA; for N=2 such realization is provided explicitly.

hep-th

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.

hep-th

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.

hep-th

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.

hep-th

Bitwistor Formulation Of The Spinning Particle

A twistorial formulation of a particle of arbitrary spin has been constructed. Equations of the twistor formulation are obtained for massive and massless spinning particles. The twistor space of the massive particle is formed by two twistors and two complex scalars. In the massive case, integral transformations relating twistor fields with usual space-time fields have been constructed.

hep-th

Bitwistor formulation of massive spinning particle

Twistor formulation of massive arbitrary spin particle has been constructed. Twistor space of such particle is formed two twistors and two complex scalars which form together 'bosonic supertwistor'. The formulation is deduced from space-time one for spinning particle by means of introducing auxiliary harmonic variables and consequent partial fixing of gauges. It is carried out the canonical quantization of twistor massive particle with nonzero spin. It is found the eigenvalues of Casimir operators on particle states and harmonic expansion of wave function in spectrum.

hep-th

Twistorial superparticle with tensorial central charges

A twistorial formulation of the N=1 D=4 superparticle with tensorial central charges describing massive and massless cases in uniform manner is given. The twistors resolve energy-momentum vector whereas the tensorial central charges are written in term of spinor Lorentz harmonics. The model makes possible to describe states preserving all allowed fractions of target-space supersymmetry. The full analysis of the number of conserved supersymmetries in models with N=1 D=4 superalgebra with tensorial central charges has been carried out.

hep-th

Uniform Twistor-Like Formulation of Massive and Massless Superparticles with Tensorial Central Charges

We construct the manifestly Lorentz-invariant twistorial formulation of N=1 D=4 superparticle with tensorial central charges which describes massive and massless cases in a uniform manner. The tensorial central charges are realized in terms of even spinor variables and central charge coordinates. The full analysis of the number of conserved supersymmetries has been carried out. In the massive case the superparticle preserves 1/4 or 1/2 of target-space supersymmetries whereas the massless superparticle preserves two or three supersymmetries.

hep-th

Massive Superparticle with Tensorial Central Charges

We construct the manifestly Lorenz-invariant formulation of the N=1 D=4 massive superparticle with tensorial central charges. The model contains a real parameter k and at $k\ne 0$ possesses one $κ$-symmetry while at k=0 the number of $κ$-symmetry is two. The equivalence of the formulations at all $k\ne 0$ is obtained. The local transformations of $κ$-symmetry are written out. It is considered the using of index spinor for construction of the tensorial central charges. It is obtained the equivalence at classical level between the massive D=4 superparticle with one $κ$-symmetry and the massive D=4 spinning particle

hep-th