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Makoto Sakaguchi

Publications and source records attributed to Makoto Sakaguchi.

At least 19 recordsLinked to original sources

Higher-Spin Gauge Models in the BRST-antifield Formalism

We examine the mass shell condition of the bosonic higher spin gauge models which are BRST deformations of the Fronsdal action in the BRST-antifield formalism. Assuming convergence of the infinite series of the deformation parameter, we will find that these models are free on-shell. We further investigate whether this nature persists for models with fermions and models on AdS spaces. We find that these models also turn out to be free on-shell after all. Furthermore, we point out that the cubic vertices of these models are BRST-exact.

hep-th

A Comment on the Higher-Spin Gauge Models

We examine the higher-spin gauge models which are free on-shell and whose cubic vertex is BRST-exact. We show that these are free off-shell as well as on-shell. The key equation for this relates the derivative of the total deformed action $S(g)$ with respect to the deformation parameter $g$ to an $S(g)$-exact term.

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Supersymmetric Non-abelian DBI Equations from Open Pure Spinor Superstring

The BRST invariance of the open pure spinor superstring is examined in the presence of background superfields on a Dp-brane. We note that the background superfields introduced in this paper depend on boundary fermions. The BRST invariance leads to supersymmetric Dirac-Born-Infeld (DBI) equations for background superfields depending on boundary fermions as well as boundary conditions on spacetime coordinates. After quantizing boundary fermions, background superfields are promoted to non-abelian ones. As a result, we obtain the supersymmetric non-abelian DBI equations from the supersymmetric DBI equations depending on boundary fermions. It is shown that these non-abelian DBI equations reduce to the super-Yang-Mills equations in the limit alpha' -> 0. We also show the nilpotency of the BRST transformation of boundary fermions.

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On Interacting Higher Spin Bosonic Gauge Fields in BRST-antifield Formalism

We examine interacting bosonic higher spin gauge fields in the BRST-antifield formalism. Assuming that an interacting action $S$ is a deformation of the free action with a deformation parameter $g$, we solve the master equation $(S,S)=0$ from the lower orders in $g$. It is shown that choosing a certain cubic interaction as the first order deformation, we can solve the master equation and obtain an action containing all orders in $g$. The anti-ghost number of the obtained action is less than or equal to two. Furthermore we show that the obtained action is lifted to that of interacting bosonic higher spin gauge fields on anti-de Sitter spaces.

hep-th

Supersymmetric DBI Equations in Diverse Dimensions from BRS Invariance of Pure Spinor Superstring

We examine the BRS invariance of the open pure spinor superstring in the presence of background superfields on a Dp-brane. It is shown that the BRS invariance leads not only to boundary conditions on the spacetime spinors, but also to supersymmetric DBI equations of motion for the background superfields on the Dp-brane. These DBI equations are consistent with the supersymmetric DBI equations for a D9-brane.

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Non-commutative M-branes from Open Pure Spinor Supermembrane

Open supermembrane with a constant three-form flux in the pure spinor formalism is examined. The BRST symmetry of the open supermembrane action leads to non-commutative (NC) M-branes. In addition to the NC M5-brane with a self-dual two-form flux, we find a NC M9-brane with an electric flux and a NC M9-brane with a magnetic flux. The former reduces in the critical electric flux limit to an M2-brane on the M9-brane, while the latter reduces in the strong magnetic flux limit to infinitely many Kaluza-Klein monopoles dissolved into the M9-brane. These NC M-branes are shown to preserve a half of 32 supersymmetries.

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A Note on Supersymmetries in AdS_5/CFT_4

The N=4 superconformal algebra is derived from the symmetry transformations of fields in the N=4 SYM action in D=4. We use a Majorana-Weyl spinor in D=10 instead of four Weyl spinors in D=4. This makes it transparent to relate generators of the N=4 superconformal algebra to those of the super-AdS_5XS^5 algebra. Especially, we obtain the concrete map from the supersymmetries Q and conformal supersymmetries S in N=4 SYM to the supersymmetries (Q_1, Q_2) in the AdS_5XS^5 background.

hep-th

D-branes from Pure Spinor Superstring in AdS_5 x S^5 Background

We examine the surface term for the BRST transformation of the open pure spinor superstring in an AdS_5 x S^5 background. We find that the boundary condition to eliminate the surface term leads to a classification of possible configurations of 1/2 supersymmetric D-branes.

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No pair production of open strings in a plane-wave background

We consider whether an external electric field may cause the pair production of open strings in a type IIA plane-wave background. The boundary states of D-branes with condensates are constructed in the Green-Schwarz formulation of superstring theory with the light-cone gauge. The cylinder diagrams are computed with massive theta functions. Although the value of the electric field is bounded by the upper value, there is no pole in the amplitudes and it indicates that no pair production occurs in the plane-wave background. This result would be universal for a class of plane-wave backgrounds.

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Semiclassical Analysis of M2-brane in AdS_4 x S^7 / Z_k

We start from the classical action describing a single M2-brane on AdS_4 x S^7/ Z_k and consider semiclassical fluctuaitions around a static, 1/2 BPS configuration whose shape is AdS_2 x S^1. The internal manifold S^7/ Z_k is described as a U(1) fibration over CP^3 and the static configuration is wrapped on the U(1) fiber. Then the configuration is reduced to an AdS_2 world-sheet of type IIA string on AdS_4 x CP^3 through the Kaluza-Klein reduction on the S^1. It is shown that the fluctuations form an infinite set of N=1 supermultiplets on AdS_2, for k=1,2. The set is invariant under SO(8) which may be consistent with N=8 supersymmetry on AdS_2. We discuss the behavior of the fluctuations around the boundary of AdS_2 and its relation to deformations of Wilson loop operator.

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Super Galilean conformal algebra in AdS/CFT

Galilean conformal algebra (GCA) is an Inonu-Wigner (IW) contraction of a conformal algebra, while Newton-Hooke string algebra is an IW contraction of an AdS algebra which is the isometry of an AdS space. It is shown that the GCA is a boundary realization of the Newton-Hooke string algebra in the bulk AdS. The string lies along the direction transverse to the boundary, and the worldsheet is AdS_2. The one-dimensional conformal symmetry so(2,1) and rotational symmetry so(d) contained in the GCA are realized as the symmetry on the AdS_2 string worldsheet and rotational symmetry in the space transverse to the AdS_2 in AdS_{d+2}, respectively. It follows from this correspondence that 32 supersymmetric GCAs can be derived as IW contractions of superconformal algebras, psu(2,2|4), osp(8|4) and osp(8^*|4). We also derive less supersymmetric GCAs from su(2,2|2), osp(4|4), osp(2|4) and osp(8^*|2).

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Non-Relativistic M2-brane Gauge Theory and New Superconformal Algebra

We study non-relativistic limits of the N=6 Chern-Simons-Matter theory that arises as a low-energy limit of the M2-brane gauge theory with background flux. The model admits several different non-relativistic limits and we find that the maximal supersymmetry we construct has 14 components of supercharges, which is a novel example of non-relativistic superconformal algebra in (1+2) dimension. We also investigate the other limits that realize less supersymmetries.

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Interacting SUSY-singlet matter in non-relativistic Chern-Simons theory

We construct an example of supersymmetric Chern-Simons-matter theory with a matter field transforming as a singlet representation of the supersymmetry algebra, where the bosonic and fermionic degrees of freedom do not match. This is obtained as a non-relativistic limit of the N=2 Chern-Simons-matter theory in 1+2 dimensions, where the particle and anti-particle coexist. We also study the index to investigate the mimatch of bosonic and fermionic degrees of freedom.

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A family of super Schrodinger invariant Chern-Simons matter systems

We investigate non-relativistic limits of the N=3 Chern-Simons matter system in 1+2 dimensions. The relativistic theory can generate several inequivalent super Schodinger invariant theories, depending on the degrees of freedom we choose to retain in the non-relativistic limit. The maximally supersymmetric Schrodinger invariant theory is obtained by keeping all particle degrees of freedom. The other descendants, where particles and anti-particles coexist, are also Schrodinger invariant but preserve less supersymmetries. Thus, we have a family of super Schrodinger invariant field theories produced from the parent relativistic theory.

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Super Schrodinger algebra in AdS/CFT

We discuss (extended) super Schrodinger algebras obtained as subalgebras of the superconformal algebra psu(2,2|4). The Schrodinger algebra with two spatial dimensions can be embedded into so(4,2). In the superconformal case the embedded algebra may be enhanced to the so-called super Schrodinger algebra. In fact, we find an extended super Schrodinger subalgebra of psu(2,2|4). It contains 24 supercharges (i.e., 3/4 of the original supersymmetries) and the generators of so(6), as well as the generators of the original Schrodinger algebra. In particular, the 24 supercharges come from 16 rigid supersymmetries and half of 16 superconformal ones. Moreover, this superalgebra contains a smaller super Schrodinger subalgebra, which is a supersymmetric extension of the original Schrodinger algebra and so(6) by eight supercharges (half of 16 rigid supersymmetries). It is still a subalgebra even if there are no so(6) generators. We also discuss super Schrodinger subalgebras of the superconformal algebras, osp(8|4) and osp(8^*|4).

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More super Schrodinger algebras from psu(2,2|4)

We discuss super Schrodinger algebras with less supercharges from N=4 superconformal algebra psu(2,2|4). Firstly N=2 and N=1 superconformal algebras are constructed from the psu(2,2|4) via projection operators. Then a super Schrodinger subalgebra is found from each of them. The one obtained from N=2 has 12 supercharges with su(2)^2 x u(1) and the other from N=1 has 6 supercharges with u(1)^3,. By construction, those are still subalgebras of psu(2,2|4). Another super Schrodinger algebra, which preserves 6 supercharges with a single u(1) symmetry, is also obtained from N=1 superconformal algebra su(2,2|1). In particular, it coincides with the symmetry of N=2 non-relativistic Chern-Simons matter system in three dimensions.

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A Semiclassical String Description of Wilson Loop with Local Operators

We discuss a semiclassical string description to circular Wilson loops without/with local operator insertions. By considering a semiclassical approximation of type IIB string theory on AdS_5 X S^5 around the corresponding classical solutions, quadratic actions with respect to fluctuations are computed. Then the dual corresponding operators describing the fluctuations are discussed from the point of view of a small deformation of the Wilson loops. The result gives new evidence for AdS/CFT correspondence.

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Holography of Non-relativistic String on AdS5xS5

We discuss a holographic dual of a non-relativistic (NR) string on AdS5xS5. The NR string can be regarded as a semiclassical string around an AdS2 classical solution corresponding to a straight Wilson line in the gauge-theory side. The quadratic action with respect to the fluctuations is composed of free massive and massless scalars, and free massive fermions on the AdS2 world-sheet. We show that the complete agreement of the spectra between the NR string and a conformal quantum mechanics (CQM). Then we show a holographic relation between normalizable modes of the NR string and wave functions in the CQM. Then it may be argued from this result that an AdS2/CFT1 would be realized in AdS5/CFT4. We can really discuss a GKPW-type relation by considering non-normalizable modes of the NR string in Euclidean signature. Those modes give a source term insertion to the Wilson line, which can also be regarded as a small deformation of it.

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