arXiv subjects

Evgeny Ivanov

Publications and source records attributed to Evgeny Ivanov.

At least 55 records · Page 3Linked to original sources

arXiv2016

Long N=2, 4 multiplets in supersymmetric mechanics

We define SU(2|1) supermultiplets described by chiral superfields having non-zero external spins with respect to SU(2) \subset SU(2|1) and show that their splitting into N=2, d=1 multiplets contains the so called "long" indecomposable N=2, d=1 multiplets (2, 4, 2)_l. We give superfield formulation for this type of N=2 long multiplets and construct their most general superfield action. A simple example of long N=4, d=1 multiplet is also considered, both in the superfield and the component formulations.

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arXiv2015

Five Lectures on Supersymmetry: Elementary Introduction

These five lectures collect elementary facts about 4D supersymmetric theories with emphasis on N=1 supersymmetry, as well as the basic notions of supersymmetric quantum mechanics. Contents: I. From symmetries to supersymmetry; II. Basic features of supersymmetry; III. Representations of supersymmetry; IV. Superspace and superfields; V. Supersymmetric quantum mechanics.

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arXiv2013

New Approach to Duality-Invariant Nonlinear Electrodynamics

We survey a new approach to the duality-invariant systems of nonlinear electrodynamics, based on introducing auxiliary bi-spinor fields. In this approach, the entire information about the given self-dual system is encoded in the U(1) invariant interaction of the auxiliary fields, while the standard self-dual Lagrangians appear on shell as a result of eliminating auxiliary fields by their equations of motion. Starting from the simplest U(1) duality, we show how this approach can be generalized to the U(N) duality (with N independent Maxwell field strengths), as well as to self-dual systems of {\cal N}=1 supersymmetric electrodynamics. Also, it works perfectly for self-dual systems with higher derivatives in the action.

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arXiv2013

N=4 mechanics with diverse (4,4,0) multiplets: explicit examples of HKT, CKT, and OKT geometries

We present simple models of N=4 supersymmetric mechanics with ordinary and mirror linear (4,4,0) multiplets that give a transparent description of HKT, CKT, and OKT geometries. These models are treated in the N=4 and N=2 superfield approaches, as well as in the component approach. Our study makes manifest that the CKT and OKT supersymmetric sigma models are distinguished from the more simple HKT models by the presence of extra holomorphic torsions in the supercharges.

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arXiv2013

Auxiliary superfields in N=1 supersymmetric self-dual electrodynamics

We construct the general formulation of N=1 supersymmetric self-dual abelian gauge theory involving auxiliary chiral spinor superfields. Self-duality in this context is just U(N) invariance of the nonlinear interaction of the auxiliary superfields. Focusing on the U(1) case, we present the most general form of the U(1) invariant auxiliary interaction, consider a few instructive examples and show how to generate self-dual N=1 models with higher derivatives in this approach.

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arXiv2012

Nahm equations in supersymmetric mechanics

We elaborate on a novel model of N=4 supersymmetric mechanics with extra spin variables. A dynamical linear (1,4,3) multiplet is coupled to a "semi-dynamical" linear (3,4,1) multiplet representing spin degrees of freedom in a Wess-Zumino action. The unique coupling of these two multiplets relates the dynamical bosonic variable to an arbitrary harmonic function of the SU(2) triplet of spin variables. As we prove at the classical and quantum level, N=4 supersymmetry is equivalent to the Nahm equations for the spin variables, with the dynamical boson as evolution parameter. We treat in detail the one- and two-monopole as well as some special multi-monopole configurations. While one monopole exhibits superconformal OSp(4|2) symmetry and was worked out previously, only N=4, d=1 Poincare supersymmetry survives for multi-monopole configurations.

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arXiv2012

Superconformal mechanics

We survey the salient features and problems of conformal and superconformal mechanics and portray some of its developments over the past decade. Both classical and quantum issues of single- and multiparticle systems are covered.

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arXiv2011

Galilean Conformal Mechanics from Nonlinear Realizations

We apply the nonlinear realizations method for constructing new Galilean conformal mechanics models. Our starting point is the Galilean conformal algebra which is a non-relativistic contraction of its relativistic counterpart. We calculate Maurer-Cartan one-forms, examine various choices of the relevant coset spaces and consider the geometric inverse Higgs-type constraints which reduce the number of the independent coset parameters and, in some cases, provide dynamical equations. New Galilean conformally invariant actions are derived in arbitrary space-time dimension D=d+1 (no central charges), as well as in the special dimension D=2+1 with one "exotic" central charge. We obtain new classical mechanics models which extend the standard (D=0+1) conformal mechanics in the presence of d non-vanishing space dimensions.

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arXiv2010

N=4, 3D Supersymmetric Quantum Mechanics in Non-Abelian Monopole Background

Using the harmonic superspace approach, we construct the three-dimensional N=4 supersymmetric quantum mechanics of the supermultiplet (3,4,1) coupled to an external SU(2) gauge field. The off-shell N=4 supersymmetry requires the gauge field to be a static form of the 't Hooft ansatz for the 4D self-dual SU(2) gauge fields, that is a particular solution of Bogomolny equations for BPS monopoles. We present the explicit form of the corresponding superfield and component actions, as well as of the quantum Hamiltonian and N=4 supercharges. The latter can be used to describe a more general N=4 mechanics system, with an arbitrary BPS monopole background and on-shell N=4 supersymmetry. The essential feature of our construction is the use of semi-dynamical spin (4,4,0) multiplet with the Wess-Zumino type action.

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arXiv2010

M2-Branes in N=3 Harmonic Superspace

We give a brief account of the recently proposed N=3 superfield formulation of the N=6, 3D superconformal theory of Aharony et al (ABJM) describing a low-energy limit of the system of multiple M2-branes on the AdS_4 x S^7/Z_k background. This formulation is given in harmonic N=3 superspace and reveals a number of surprising new features. In particular, the sextic scalar potential of ABJM arises at the on-shell component level as the result of eliminating appropriate auxiliary fields, while there is no any explicit superpotential at the off-shell superfield level.

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arXiv2010

New D(2,1;alpha) Mechanics with Spin Variables

We elaborate on a novel superconformal mechanics model possessing D(2,1;alpha) symmetry and involving extra U(2) spin variables. It is the one-particle case of the N=4 superconformal matrix model recently proposed in arXiv:0812.4276 [hep-th], and it generalizes to arbitrary alpha\neq0 the OSp(4|2) superconformal mechanics of arXiv:0905.4951 [hep-th]. As in the latter case, the U(2) spin variables are described by a Wess-Zumino action and define the first Hopf map S^3 -> S^2 in the target space. Upon quantization, they represent a fuzzy sphere. We find the classical and quantum generators of the D(2,1;alpha) superalgebra and their realization on the physical states. The super wavefunction encompasses various multiplets of the SU(2)_R and SU(2)_L subgroups of D(2,1;alpha), with fixed isospins. The conformal potential is determined by the external magnetic field in the Wess-Zumino term, whose amplitude is quantized like in the OSp(4|2) case. As a byproduct, we reveal new invariant subspaces in the enveloping algebra of D(2,1;alpha) for our quantum realization.

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arXiv2010

Generalized N = 2 Super Landau Models

We generalize previous results for the superplane Landau model to exhibit an explicit worldline N = 2 supersymmetry for an arbitrary magnetic field on any two-dimensional manifold. Starting from an off-shell N = 2 superfield formalism, we discuss the quantization procedure in the general case characterized by two independent potentials on the manifold and show that the relevant Hamiltonians are factorizable. In the restricted case when both the Gauss curvature and the magnetic field are constant over the manifold and, as a consequence, the underlying potentials are related, the Hamiltonians admit infinite series of factorization chains implying the integrability of the associated systems. We explicitly determine the spectrum and eigenvectors for the particular model with CP^1 as the bosonic manifold.

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arXiv2010

New Super Calogero Models and OSp(4|2) Superconformal Mechanics

We report on the new approach to constructing superconformal extensions of the Calogero-type systems with an arbitrary number of involved particles. It is based upon the superfield gauging of non-abelian isometries of some supersymmetric matrix models. Among its applications, we focus on the new N=4 superconformal system yielding the U(2) spin Calogero model in the bosonic sector, and the one-particle case of this system, which is a new OSp(4|2) superconformal mechanics with non-dynamical U(2) spin variables. The characteristic feature of these models is that the strength of the conformal inverse-square potential is quantized.

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arXiv2009

OSp(4|2) Superconformal Mechanics

A new superconformal mechanics with OSp(4|2) symmetry is obtained by gauging the U(1) isometry of a superfield model. It is the one-particle case of the new N=4 super Calogero model recently proposed in arXiv:0812.4276 [hep-th]. Classical and quantum generators of the osp(4|2) superalgebra are constructed on physical states. As opposed to other realizations of N=4 superconformal algebras, all supertranslation generators are linear in the odd variables, similarly to the N=2 case. The bosonic sector of the component action is standard one-particle (dilatonic) conformal mechanics accompanied by an SU(2)/U(1) Wess-Zumino term, which gives rise to a fuzzy sphere upon quantization. The strength of the conformal potential is quantized.

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arXiv2009

Supersymmetric Calogero models by gauging

New superconformal extensions of d=1 Calogero-type systems are obtained by gauging the U(n) isometry of matrix superfield models. We consider the cases of N=1, N=2 and N=4 one-dimensional supersymmetries. The bosonic core of the N=1 and N=2 models is the standard conformal A_{n-1} Calogero system, whereas the N=4 model is an extension of the U(2)-spin Calogero system.

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arXiv2008

Unitary Spherical Super-Landau Models

A Hilbert space metric is found for the SU(2|1)-invariant `superflag' Landau models, parametrized by integer 2N' and real number M, such that the Hilbert space norm is positive definite. The spectrum of these unitary super-Landau models is determined. The M=0 case yields a unitary Landau model on the supersphere SU(2|1)/U(1|1) with U(1) charge 2N=2N'+1. For the generic unitary superflag model, the manifest SU(2|1) symmetry is dynamically enhanced to SU(2|2); this is the `spherical' analog of the hidden worldline supersymmetry found previously in the planar limit.

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arXiv2007

Hierarchy of N=8 Mechanics Models

Using the N=4 superspace approach in one dimension (time), we construct general N=8 supersymmetric mechanics actions for the multiplets (b,8,8-b) classified in hep-th/0406015, with the main focus on the previously unexplored cases of (8,8,0), (7,8,1) and (6,8,2), as well as on (5,8,3) for completeness. N=8 supersymmetry of the action amounts to a harmonicity condition for the Lagrangian with respect to its superfield arguments. We derive the generic off-shell component action for the ``root'' multiplet (8,8,0), prove that the actions for all other multiplets follow from it through automorphic dualities and argue that this hierarchical structure is universal. The bosonic target geometry in all cases is conformally flat, with a unique scalar potential (except for the root multiplet). We show that the N=4 superfield constraints respect the full R-symmetry and find the explicit realization of its quotient over the manifest R-symmetry on superfields and component fields. Several R-symmetric N=4 superfield Lagrangians with N=8 supersymmetry are either newly found or reproduced by a simple universal method.

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arXiv2007

Supersymmetrizing Landau Models

This is an overview of recent progress in constructing and studying superextensions of the Landau problem of a quantum particle on a plane in the uniform magnetic field, as well as of its Haldane's $S^2$ generalization ({\tt hep-th/0311159, hep-th/0404108, hep-th/0510019, hep-th/0612300}). The main attention is paid to the planar super Landau models which are invariant under the inhomogeneous supergroup ISU(1|1), a contraction of the supergroup SU(2|1), and provide minimal superextensions of the original Landau model. Their common notable feature is the presence of a hidden dynamical worldline N=2 supersymmetry. It exists at the classical and quantum levels and is revealed most naturally while passing to the new invariant inner products in the space of quantum states in order to make the norms of all states positive. For one of the planar models, the superplane Landau model, we present an off-shell worldline superfield formulation in which the N=2 supersymmetry gets manifest.

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