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Fa-Min Chen

Publications and source records attributed to Fa-Min Chen.

14 recordsLinked to original sources

A 6D nonabelian $(1,0)$ Theory

We construct a 6D nonabelian ${\cal N}=(1,0)$ theory by coupling an ${\cal N}=(1,0)$ tensor multiplet to an ${\cal N}=(1, 0)$ hypermultiplet. While the ${\cal N}=(1, 0)$ tensor multiplet is in the adjoint representation of the gauge group, the hypermultiplet can be in the fundamental representation or any other representation. If the hypermultiplet is also in the adjoint representation of the gauge group, the supersymmetry is enhanced to ${\cal N}=(2, 0)$, and the theory is identical to the $(2,0)$ theory of Lambert and Papageorgakis (LP). Upon dimension reduction, the $(1,0)$ theory can be reduced to a general ${\cal N}=1$ supersymmetric Yang-Mills theory in 5D. We discuss briefly the possible applications of the theories to multi M5-branes.

hep-th

Constructing Nonabelian (1,0) Hypermultiplet Theories in Six Dimensions

We construct a class of nonabelian superconformal (1,0) hypermultiplet theories in six dimensions by introducing an abelian auxiliary field. The gauge fields of this class of theories are non-dynamical, and this class of theories can be viewed as Chern-Simons-matter theories in 6D.

hep-th

General Wigner Rotations in $D$ Dimensions

We construct general Wigner rotations for both massive and massless particles in $D$-dimensional spacetime. We work out the explicit expressions of these Wigner rotations for arbitrary Lorentz transformations. We study the relation between the electromagnetic gauge invariance and the non-uniqueness of Wigner rotation.

hep-th

A Nonabelian $(1,0)$ Tensor Multiplet Theory in 6D

We construct a general nonabelian (1,0) tensor multiplet theory in six dimensions. The gauge field of this (1,0) theory is non-dynamical, and the theory contains a continuous parameter $b$. When $b=1/2$, the (1,0) theory possesses an extra discrete symmetry enhancing the supersymmetry to (2,0), and the theory turns out to be identical to the (2,0) theory of Lambert and Papageorgakis (LP). Upon dimension reduction, we obtain a general ${\cal N}=1$ supersymmetric Yang-Mills theory in five dimensions. The applications of the theories to D4 and M5-branes are briefly discussed.

hep-th

OSp(5|4) Superconformal Symmetry of N=5 Chern-Simons Theory

We demonstrate that the general D=3, N=5 Chern-Simons matter theory possesses a full OSp(5|4) superconformal symmetry, and construct the corresponding superconformal currents. The closure of the superconformal algebra is verified in detail. We also show that the conserved OSp(6|4) superconformal currents in the general N=6 theory can be obtained as special cases of the OSp(5|4) currents by enhancing the R-symmetry of the N=5 theory from USp(4) to SU(4).

hep-th

OSp(4|4) superconformal currents in three-dimensional N=4 Chern-Simons quiver gauge theories

We prove explicitly that the general D=3, N=4 Chern-Simons-matter (CSM) theory has a complete OSp(4|4) superconformal symmetry, and construct the corresponding conserved currents. We re-derive the OSp(5|4) superconformal currents in the general N=5 theory as special cases of the OSp(4|4) currents by enhancing the supersymmetry from N=4 to N=5. The closure of the full OSp(4|4) superconformal algebra is verified explicitly.

hep-th

Construction of New D=3, N=4 Quiver Gauge Theories

In this paper we propose a special class of 3-algebras, called double-symplectic 3-algebras. We further show that a consistent contraction of the double-symplectic 3-algebra gives a new 3-algebra, called an N=4 three-algebra, which is then identified as the exact gauged three-algebra in the N=4 quiver gauge theories. A systematic construction is proposed for the 3-brackets and fundamental identities used in building up the N=4 theories, by starting with two superalgebras whose bosonic parts share at least one simple factor or U(1) factor. This leads to a systematic way of constructing D=3, N=4 quiver theories, of which several examples with new gauge groups are presented in detail. The general N=4 superconformal Chern-Simons matter theories in terms of ordinary Lie algebras can be also re-derived in our new 3-algebra approach.

hep-th

Fusion of Superalgebras and D=3, N=4 Quiver Gauge Theories

For further investigating the underlying structures of the D=3, N=4 Chern-Simons-matter (CSM) theories, we suggest a new concept and procedure for "fusing" two superalgebras into a single new superalgebra. The starting superalgebras may be those used in the previous construction of the double-symplectic 3-algebras in the N=4 CSM theories: The bosonic parts of these two superalgebras share at least one simple factor or U(1) factor. We are able to provide two different methods to do the "fusion". Several explicit examples are presented to demonstrate the "fusion" procedure. We also generalize the "fusion" procedure so that more than two superaglebras can be fused into a single one, provided some conditions are satisfied. It is shown that two or more N=4 theories with different gauge groups may be associated with the same "fused" superalgebra.

hep-th

Superalgebra Realization of the 3-algebras in N=6, 8 Chern-Simons-matter Theories

We use superalgebras to realize the 3-algebras used to construct N=6, 8 Chern-Simons-matter (CSM) theories. We demonstrate that the superalgebra realization of the 3-algebras provides a unified framework for classifying the gauge groups of the N \geq 5 theories based on 3-algebras. Using this realization, we rederive the ordinary Lie algebra construction of the general N=6 CSM theory from its 3-algebra counterpart, and reproduce all known examples as well. In particular, we explicitly construct the Nambu 3-bracket in terms of a double graded commutator of PSU(2|2). The N = 8 theory of Bagger, Lambert and Gustavsson (BLG) with SO(4) gauge group is constructed by using several different ways. A quantization scheme for the 3-brackets is proposed by promoting the double graded commutators as quantum mechanical double graded commutators.

hep-th

Superspace Formulation in a Three-Algebra Approach to D=3, N=4,5 Superconformal Chern-Simons Matter Theories

We present a superspace formulation of the D=3, N=4,5 superconformal Chern-Simons Matter theories, with matter supermultiplets valued in a symplectic 3-algebra. We first construct an N=1 superconformal action, and then generalize a method used by Gaitto and Witten to enhance the supersymmetry from N=1 to N=5. By decomposing the N=5 supermultiplets and the symplectic 3-algebra properly and proposing a new super-potential term, we construct the N=4 superconformal Chern-Simons matter theories in terms of two sets of generators of a (quaternion) symplectic 3-algebra. The N=4 theories can also be derived by requiring that the supersymmetry transformations are closed on-shell. The relationship between the 3-algebras, Lie superalgebras, Lie algebras and embedding tensors (proposed in [E. A. Bergshoeff, O. Hohm, D. Roest, H. Samtleben, and E. Sezgin, J. High Energy Phys. 09 (2008) 101.]) is also clarified. The general N=4,5 superconformal Chern-Simons matter theories in terms of ordinary Lie algebras can be rederived in our 3-algebra approach. All known N=4,5 superconformal Chern-Simons matter theories can be recovered in the present superspace formulation for super-Lie-algebra realization of symplectic 3-algebras.

hep-th

Covariantly Constant Curvature Tensors and D=3, N=4, 5, 8 Chern-Simons Matter Theories

We construct some examples of D=3, N=4 GW theory and N=5 superconformal Chern-Simons matter theory by using the covariantly constant curvature of a quaternionic-Kahler manifold to construct the symplectic 3-algebra in the theories. Comparing with the previous theories, the N=4, 5 theories constructed in this way possess a local Sp(2n) symmetry and a diffeomorphism symmetry associated with the quaternionic-Kahler manifold. We also construct a generalized N=8 BLG theory by utilizing the dual curvature operator of a maximally symmetric space of dimension 4 to construct the Nambu 3-algebra. Comparing with the previous N=8 BLG theory, the theory has a diffeomorphism invariance and a local SO(4) invariance associated with the symmetric space.

hep-th

Symplectic Three-Algebra Unifying N=5,6 Superconformal Chern-Simons-Matter Theories

We define a 3-algebra with structure constants being symmetric in the first two indices. We also introduce an invariant anti-symmetric tensor into this 3-algebra and call it a symplectic 3-algebra. The general N=5 superconformal Chern-Simons-matter (CSM) theory with SO(5) R-symmetry in three dimensions is constructed by using this algebraic structure. We demonstrate that the supersymmetry can be enhanced to N=6 if the sympelctic 3-algebra and the fields are decomposed in a proper fashion. By specifying the 3-brackets, some presently known N=5, 6 superconformal theories are described in terms of this unified 3-algebraic framework. These include the N=5, Sp(2N) X O(M) CSM theory with SO(5) R-symmetry , the N=6, Sp(2N) X U(1) CSM theory with SU(4) R-symmetry, as well as the ABJM theory as a special case of U(M) X U(N) theory with SU(4) R-symmetry.

hep-th

Symplectic Three-Algebra and N=6, Sp(2N) X U(1) Superconformal Chern-Simons-Matter Theory

We introduce an anti-symmetric metric into a 3-algebra and call it a symplectic 3-algebra. The N=6, Sp(2N) X U(1) superconformal Chern-Simons-matter theory with SU(4) R-symmetry in three dimensions is constructed by specifying the 3-brackets in a symplectic 3-algebra. We also demonstrate that the N=6, U(M) X U(N) theory can be recast into this symplectic 3-algebraic framework.

hep-th