arXiv subjects

Jeong-Hyuck Park

Publications and source records attributed to Jeong-Hyuck Park.

85 records · Page 5Linked to original sources

arXiv2002

Solitons in a Grassmannian sigma-model Coupled to Chern-Simons Term

We propose an exactly solvable Grassmannian sigma-model coupled to the Chern-Simons theory. In the presence of a novel topological term our model admits exact self-dual vortex solutions which are identical to those of pure Grassmannian model, but the topological charge has a physical meaning as a magnetic flux since the gauge field is no longer auxiliary. We also extend the theory to a noncommutative plane and analyze the BPS solutions.

hep-th↗

arXiv2002

BPS equations in Six and Eight Dimensions

We consider the maximal supersymmetric pure Yang-Mills theories on six and eight dimensional space. We determine, in a systematic way, all the possible fractions of supersymmetry preserved by the BPS states and present the corresponding `self-dual' BPS equations. In six dimensions the intrinsic one has 1/4 supersymmetry, while in eight dimensions, 1/16, 2/16, ..., 6/16. We apply our results to some explicit BPS configurations of finite or infinite energy on commutative or noncommutative spaces.

hep-th↗

arXiv2001

On a Matrix Model of Level Structure

We generalize the dimensionally reduced Yang-Mills matrix model by adding d=1 Chern-Simons term and terms for a bosonic vector. The coefficient, κof the Chern-Simons term must be integer, and hence the level structure. We show at the bottom of the Yang-Mills potential, the low energy limit, only the linear motion is allowed for D0 particles. Namely all the particles align themselves on a single straight line subject to κ^2/r^2 repulsive potential from each other. We argue the relevant brane configuration to be D0-branes in a D4 after κof D8's pass the system.

hep-th↗

arXiv2001

A Study of Two-/One-form Superfields

We study two supersymmetric toy models of a k-form superfield, k=2,1 separately. By ``solving'' Jacobi identities, we show that each model is completely solvable at off-shell level, possesses a severely constrained kinematics, and gives a rigid representation of the supersymmetry algebra. This study of the toy models is motivated by our reanalysis on supersymmetry algebras in gauge theories where we discuss internal symmetry generators carrying spacetime/spinor indices.

math-ph↗

arXiv2001

Chern-Simons Theories on Noncommutative Plane

We investigate U(N) Chern-Simons theories on noncommutative plane. We show that for the theories to be consistent quantum mechanically, the coefficient of the Chern-Simons term should be quantized $κ= n/2π$ with an integer $n$. This is a surprise for the U(1) gauge theory. When uniform background charge density $ρ_e$ is present, the quantization rule changes to $κ+ρ_eθ= n/2π$ with noncommutative parameter $θ$. With the exact expression for the angular momentum, we argue in the U(1) theory that charged particles in the symmetric phase carry fractional spin $1/2n$ and vortices in the broken phase carry half-integer or integer spin $-n/2$.

hep-th↗

arXiv2000

Comments on Noncommutative Gauge Theories

We study the gauge theories on noncommutative space. We employ the idea of the covariant position to understand the linear and angular momenta, the center of mass position, and to express all gauge invariant observables including the Wilson line. In addition, we utilize the universality of the U(1) gauge theory, which originates from the underlying matrix theory, to analyze various solitons on U(N) theories, like the unstable static vortex solutions in two dimensions and BPS dyonic fluxon solutions.

hep-th↗

arXiv2000

Noncommutative Vortex Solitons

We consider the noncommutative Abelian-Higgs theory and investigate general static vortex configurations including recently found exact multi-vortex solutions. In particular, we prove that the self-dual BPS solutions cease to exist once the noncommutativity scale exceeds a critical value. We then study the fluctuation spectra about the static configuration and show that the exact non BPS solutions are unstable below the critical value. We have identified the tachyonic degrees as well as massless moduli degrees. We then discuss the physical meaning of the moduli degrees and construct exact time-dependent vortex configurations where each vortex moves independently. We finally give the moduli description of the vortices and show that the matrix nature of moduli coordinates naturally emerges.

hep-th↗

arXiv2000

5D Actions for 6D Self-Dual Tensor Field Theory

We present two equivalent five-dimensional actions for six-dimensional (N,0) N=1,2 supersymmetric theories of self-dual tensor whose one spatial dimension is compactified on a circle. The Kaluza-Klein tower consists of a massless vector and infinite number of massive self-dual tensor multiplets living in five-dimensions. The self-duality follows from the equation of motion. Both actions are quadratic in field variables without any auxiliary field. When lifted back to six-dimensions, one of them gives a supersymmetric extension of the bosonic formulation for the chiral two-form tensor by Perry and Schwarz.

hep-th↗

arXiv1999

Superconformal Symmetry in Three-dimensions

Three-dimensional N-extended superconformal symmetry is studied within the superspace formalism. A superconformal Killing equation is derived and its solutions are classified in terms of supertranslations, dilations, Lorentz transformations, R-symmetry transformations and special superconformal transformations. Superconformal group is then identified with a supermatrix group, OSp(N|2,R), as expected from the analysis on simple Lie superalgebras. In general, due to the invariance under supertranslations and special superconformal transformations, superconformally invariant n-point functions reduce to one unspecified (n-2)-point function which must transform homogeneously under the remaining rigid transformations, i.e. dilations, Lorentz transformations and R-symmetry transformations. After constructing building blocks for superconformal correlators, we are able to identify all the superconformal invariants and obtain the general form of n-point functions. Superconformally covariant differential operators are also discussed.

hep-th↗

arXiv1999

Superconformal Symmetry and Correlation Functions

Four-dimensional N-extended superconformal symmetry and correlation functions of quasi-primary superfields are studied within the superspace formalism. A superconformal Killing equation is derived and its solutions are classified in terms of supertranslations, dilations, Lorentz transformations, R-symmetry transformations and special superconformal transformations. In general, due to the invariance under supertranslations and special superconformal transformations, superconformally invariant n-point functions reduce to one unspecified (n-2)-point function which must transform homogeneously under the remaining rigid transformations, i.e. dilations, Lorentz transformations and R-symmetry transformations. Based on this result, we are able to identify all the superconformal invariants and obtain the general form of n-point functions for scalar superfields. In particular, as a byproduct, a selection rule for correlation functions is derived, the existence of which in N=4 super Yang-Mills theory was previously predicted in the context of AdS/CFT correspondence. Superconformally covariant differential operators are also discussed.

hep-th↗

arXiv1999

Superconformal Symmetry in Six-dimensions and Its Reduction to Four

Superconformal symmetry in six-dimensions is analyzed in terms of coordinate transformations on superspace. A superconformal Killing equation is derived and its solutions are identified in terms of supertranslations, dilations, Lorentz transformations, R-symmetry transformations and special superconformal transformations. The full superconformal symmetry, which is shown to form the group OSp(2,6|N), is possible only if the supersymmetry algebra has N spinorial generators of the same chirality, corresponding to (N,0) supersymmetry. The R-symmetry group is then Sp(N) and the corresponding superspace is R^{6|8N}. We define superinversion as a map to the associated superspace of opposite chirality. General formulae for two-point and three-point correlation functions of quasi-primary superfields are exhibited. The superconformal group in six-dimensions is reduced to a corresponding extended superconformal group in four-dimensions. Superconformally covariant differential operators are also discussed.

hep-th↗

arXiv1999

A Study of a Non-Abelian Generalization of the Born-Infeld Action

A new type of non-Abelian generalization of the Born-Infeld action is proposed, in which the spacetime indices and group indices are combined. The action is manifestly Lorentz and gauge invariant. In its power expansion, the lowest order term is the Yang-Mills action and the second term corresponds to the bosonic stringy correction to this action. Solutions of the Euler-Lagrange equation for the SU(2) case are considered and we show that there exists an instanton-like solution which has winding number one and finite action.

hep-th↗

arXiv1999

N=1 Superconformal Symmetry in Four Dimensions

N=1, d=4 superconformal group is studied and its representations are discussed. Under superconformal transformations, left invariant derivatives and some class of superfields, including supercurrents, are shown to follow these representations. In other words, these superfields are quasi-primary by analogy with two dimensional conformal field theory. Based on these results, we find the general forms of the two-point and the three-point correlation functions of the quasi-primary superfields in a group theoretical way. In particular, we show that the two-point function of the supercurrent is unique up to a constant and the general form of the three-point function of the supercurrent has two free parameters.

hep-th↗